PROGRAM & ABSTRACTS - Wisconsin Union - University of ...

Aging, Metabolism, Stress, Pathogenesis, and Small RNAs in C. elegans Topic Meeting 2012 

PROGRAM & ABSTRACTS 

Aging, Metabolism, Stress, Pathogenesis, and 

Small RNAs in C. elegans 

Thursday, July 12 – Sunday, July 15, 2012 

University of Wisconsin-Madison 

Union South/Memorial Union 

Madison, Wisconsin 53706 

Scientific Organizers 

Malene Hansen, Sanford-Burnham Medical Research Institute, La Jolla 

Emily Troemel, University of California, San Diego 

Organizing Committee 

Sean Curran, University of Southern California, Los Angeles 

Nils Færgeman, University of Southern Denmark, Odense, Denmark 

Danielle Garsin, University of Texas-Houston Medical School 

David Gems, University College London, United Kingdom 

Ao-Lin Hsu, University of Michigan, Ann Arbor 

Javier Irazoqui, Massachusetts General Hospital, Harvard Medical School 

Antony Jose, University of Maryland, College Park 

Ho Yi Mak, Stowers Institute for Medical Research, Kansas City, Missouri 

Dana Miller, University of Washington, Seattle 

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ii 

www.ellisonfoundation.org 

www.labexpress.com 

www.knudra.com 

SPONSORS 

ACKNOWLEDGEMENTS 

www.glennfoundation.org 

www.eppendorfna.com 

www.unionbio.com 

All sponsoring companies and University of Wisconsin Memorial Union Conference Services. 

Cover Description: Front cover image and design courtesy of Malina A. Bakowski (Troemel lab). 

Cover represents the main themes of this C. elegans Topic Meeting. 

For emergencies call (608) 890-1077 or stop by conference headquarters in Union South (Varsity Lounge)


Conference Program 

Thursday, July 12 th 

12 Noon – 7:00 pm Registration Check-In Union South, Varsity Lounge 

5:00 – 7:15 pm Opening Reception Union South, Varsity Hall 

7:15 pm Welcome and Opening Remarks Union South, Marquee 

7:30 – 10:30 pm Session 1 (Abstracts 1 – 5) Union South, Marquee 

Chairs: Danielle Garsin and Ao-Lin Hsu 

7:30 pm Keynote Speaker 

Jonathan Ewbank 

Building an integrated view of anti-fungal innate immunity 

8:30 – 9:00 pm Refreshment Break Union South, Varsity Hall 

9:00 pm Filipe Cabreiro 

Metformin increases C. elegans lifespan by altering E. coli 

folate metabolism 

(Lab: Gems) 

9:15 pm Kathleen Dumas (Lab: Hu) 

The C. elegans Dosage Compensation Protein DPY-21 

Regulates Dauer Arrest 

9:30 pm Anat Ben-Zvi (Lab: Ben-Zvi) 

Germline Stem Cells Regulate Somatic Proteostasis During 

Caenorhabditis elegans Adulthood 

9:45 pm L. Ryan Baugh (Lab: Baugh) 

Transgenerational Effects of Starvation on Development, 

Reproduction and Lifespan: Bet-hedging on an Epigenetic 

Fitness Trade-off 

Friday, July 13 th 

7:00 – 8:30 am Breakfast Union South, Varsity Hall 

8:00 am – 7:30 pm Registration/Questions Union South, Varsity Lounge 

8:00 am – 7:30 pm Poster Set-up Memorial Union, Great Hall/Reception Room 

8:30 am – 12:30 pm Session 2 (Abstracts 6 – 16) Union South, Marquee 

Chairs: Dana Miller and Matthew Gill 

8:30 am Plenary Speaker 

Siu Sylvia Lee 

Transcriptional Network Key to Longevity Determination 

and Stress Regulation 

iii


9:00 am Xiaoyan Guo (Lab: Garcia) 

SIR-2.1, an HDAC, is Required To Maintain The Male Mating 

Potency In C. elegans 

9:15 am Geert Depuydt (Lab: Braeckman) 

LC-MS Proteomics Analysis Reveals Both Common and 

Unique Changes in the Proteome of Insulin/IGF-1 Receptor 

Mutant and Dietary-Restricted C. elegans 

9:30 am Carl Franz (Lab: Wang) 

Characterization of Caenorhabditis Nematode Infecting 

Viruses 

9:45 am Alexandre de Lencastre (Lab: Slack) 

Functions of MicroRNAs During Aging 

10:00 am T. Keith Blackwell (Lab: Blackwell) 

Integration of the Unfolded Protein and Oxidative Stress 

Responses through SKN-1/Nrf 

10:15 – 10:45 am Refreshment Break Union South, Varsity Hall 

10:45 am Plenary Speaker Union South, Marquee 

Matt Kaeberlein 

Oxygen, Temperature, and Food: New Insights into the Role 

of Environment in C. elegans Aging 

11:15 am Louis Lapierre (Lab: Hansen) 

The Transcription Factor HLH-30/TFEB Regulates Autophagy 

and Modulates Longevity in C. elegans 

11:30 am Orane Visvikis (Lab: Irazoqui) 

HLH-30 Is a New Transcription Factor involved in C. elegans 

Host Response Triggered by S. aureus Infection 

11:45 am Nils Færgeman (Lab: Færgeman) 

Quantitative Proteomics Identifies SBP-1/SREBP as a General 

Transcriptional Regulator of Metabolic Pathways in C. elegans 

12:00 pm David Hall (Lab: Hall) 

Pathology of the Aging Gonad Viewed By TEM 

12:15 – 1:45 pm Luncheon Buffet Union South, Varsity Hall 


Session chairs: Ho Yi Mak and William Mair 

1:45 pm Plenary Speaker 

Kaveh Ashrafi 

New Insights Into Understanding the Regulation of Fat and 

Feeding 

2:15 pm Thomas Heimbucher (Lab: Dillin) 

Identification of DAF-16 Co-regulators with Tandem Affinity 

Purification and MudPIT 

iv


2:30 pm Emilie Demoinet (Lab: Roy) 

AMPK Regulates a Novel UPR-like Response to Mediate 

Survival During Nutrient Stress in C. elegans 

2:45 pm Panel Discussion Union South, Marquee 

Looking Ahead to Future Research Directions 


4:00 pm Plenary Speaker Union South, Marquee 

Coleen Murphy 

Pathways that regulate Reproductive Aging and Longevity 

4:30 pm Donha Park (Lab: Taubert) 

A Novel Role of TGF-β Pathway in Dietary Restriction 

Induced Longevity 

4:45 pm Ju-Ling Liu (Lab: Hekimi) 

Mitochondrial Oxidative Stress in C. elegans Alters a Pathway 

with Strong Similarities to that of Bile Acid Biosynthesis and 

Secretion in Vertebrates 

5:00 pm Justine Melo (Lab: Ruvkun) 

Surveillance of Core Cellular Processes as a Strategy for 

Xenobiotic and Pathogen Recognition 

5:30 – 7:30 pm Dinner Memorial Union, Tripp Commons 

7:30 – 9:30 pm Poster Session (Odd Numbered Posters) Memorial Union, 4th Floor 

Great Hall/Reception Room 

Aging 51 - 77 

Metabolism 79 - 93, 171 

Stress 95 - 131 

Pathogenesis 133 - 161, 169 

Small RNAs 61, 163 - 167 

Saturday, July 14 th 


8:00 am – 7:30 pm Registration/Questions Union South, Varsity Lounge 

8:30 am – 12:30 pm Session 4 (Abstracts 25 – 35) Union South, Marquee 

Session chairs: David Gems and Stefan Taubert 


Amy Pasquinelli 

Pinning Down MicroRNA Targets In Vivo 

9:00 am Nadia Storm (Lab: Antebi) 

Enhancing N-glycosylation Through Activation of the 

Hexosamine Pathway Improves ER Protein Folding Capacity 

and Slows Ageing 

v


9:15 am Yutao Chen (Lab: Baugh) 

ins-5 and ins-6 Promote Post-embryonic Development in 

Response to Feeding 

9:30 am Aimee Kao (Lab: Kenyon/Kao) 

A New Class of Stress-Resistance Genes 

9:45 am Alexander Soukas (Lab: Ruvkun/Soukas) 

Genetic Regulation of Age Pigment and Nile Red 

Accumulation in the Lysosome-Related Organelle 

10:00 am David Gems (Lab: Gems) 

A Necrotic Cascade Accelerates Stress-Induced Death and 

Causes a Burst of Anthranilic Acid Fluorescence in C. elegans 

10:15 – 10:45 am Refreshment Break Union South, Varsity Hall 


Marie-Anne Felix 

The Real Life of Caenorhabditis and Their Natural Pathogens 

11:15 am Brian Onken (Lab: Driscoll) 

Insulin Signaling and Dietary Restriction Differentially 

Regulate Glucose Metabolism to Impact C. elegans 

Healthspan 

11:30 am Suzannah Szumowski (Lab: Troemel) 

Exit of the Intracellular Pathogen Nematocida parisii from C. 

elegans Intestinal Cells 

11:45 pm Amir Sapir (Lab: Broday) 

ULP-4 SUMO protease Regulates Mitochondria Homeostasis 

During C. elegans Development and Mitochondrial Stress 

12:00 pm Jeff Simske (Lab: Simske) 

The Diet of Worms: Expression of the agl-1 (Glycogen- 

Debranching Enzyme) Embryonic Arrest Phenotype Depends 

on Maternal Diet 

12:15 – 1:45 pm Luncheon Buffet Union South, Varsity Hall 


Chairs: Arjumand Ghazi and Nils Færgeman 


Jennifer Watts 

Fatty Acid Desaturase Activity Regulates Lipid Droplet Size 

2:00 pm Nicholas Stroustrup (Lab: Fontana) 

The Lifespan Machine: A Scalable, Automated Microscope 

Increases the Throughput and Statistical Quality of 

Nematode Lifespan and Stress Resistance Assays 

2:15 am Parag Mahanti (Lab: Schroeder) 

Novel Endogenous Ligands of DAF-12 Nuclear Hormone 

Receptor Revealed by Comparative Metabolomics 

vi


2:30 pm Cole Haynes (Lab: Haynes) 

Direct Detection of Mitochondrial Dysfunction by the 

Transcription Factor ATFS-1 

2:45 pm Michael Shapira (Lab: Shapira) 

Dissecting Opposing Age-dependent Contributions of JNK 

Signaling to Stress Resistance 



Patrick Hu 

A Genetic Screen for Novel DAF-16/FoxO Regulators 

4:15 pm Markus Kunzler (Lab: Aebi) 

Interplay of Foreign and Endogenous Lectins in Innate 

Immunity of Caenorhabditis elegans 

4:30 pm Chun-Ling Sun (Lab: Crowder) 

Cell-Specific Hypoxic Injury in C. elegans: Modeling the 

Ischemic Penumbra 

4:45 pm Antony Jose (Lab: Jose) 

Movement of RNA Silencing Between C. elegans Cells 

5:00 pm Abigail Cabunoc (Lab: Stein) 

WormBase 2012: Website Redesign 

5:30 – 7:30 pm Dinner Memorial Union, Inn Wisconsin 

7:30 – 9:30 pm Poster Session (Even Numbered Posters) Memorial Union, 4th Floor 

Great Hall/Reception Room 

Aging 52 - 76 

Metabolism 78 - 92 

Stress 94 - 130, 170 

Pathogenesis 132 - 160 

Small RNAs 162 - 168 

9:30 pm – 12 Midnight Party and Dance Memorial Union, Tripp Commons 

Sunday, July 15 th 


8:00 am – 12 Noon Registration/Questions Union South, Varsity Lounge 

8:30 – 10:30 am Session 6 (Abstracts 46 – 50) Union South, Marquee 

Session Chairs: Antony Jose and Javier Irazoqui 


Dennis Kim 

Dynamic Neuroendocrine Signaling in C. elegans Behavioral 

Responses to Pathogenic Bacteria 

vii


9:00 am Rebecca Taylor (Lab: Dillin) 

The UPRER is a Cell Non-Autonomous Regulator of Stress 

Resistance and Longevity 

9:15 am Amy Walker (Lab: Naar/Walker) 

Interactions Between 1-carbon Cycle and Lipid Metabolism 

in C. elegans 

9:30 am Horishi Suzuki (Lab: Suzuki) 

Novel Approach in Oxidative Stress Study by Targeted ROS 

Generation Using a Photosensitizer SuperNova in C. elegans 


Gordon Lithgow 

Natural Products that Suppress Protein Aggregation and 

Slow Aging 

10:15 am Closing remarks 

10:30 am Refreshments and Goodbye Union South, Varsity Hall 

viii


TABLE OF CONTENTS 

Thursday, July 12, 2012 - 7:30–10:30 pm 

Session #1 - Union South, Marquee 

Abstracts 1–5 

Chairs: Danielle Garsin and Ao-Lin Hsu 

1 Keynote: Building an integrated view of anti-fungal innate immunity 

Jonathan Ewbank (Keynote Speaker) 

2 Metformin increases C. elegans lifespan by altering E. coli folate metabolism 

Filipe Cabreiro, Catherine Au, Kit-Yi Leung, Nick Greene, David Gems 

3 The C. elegans Dosage Compensation Protein DPY-21 Regulates Dauer 

Arrest 

Kathleen Dumas, Stephane Flibotte, Don Moerman, Patrick Hu 

4 Germline Stem Cells Regulate Somatic Proteostasis During Caenorhabditis 

elegans Adulthood 

Netta Shemesh, Nadav Shai, Anat Ben-Zvi 

5 Transgenerational Effects of Starvation on Development, Reproduction and 

Lifespan: Bet-hedging on an Epigenetic Fitness Trade-off 

Meghan Jobson, L. Ryan Baugh 

Friday, July 13, 2012 - 8:30 am–12:30 pm 



Chairs: Dana Miller and Matthew Gill 

6 Transcriptional Network Key to Longevity Determination and Stress 

Regulation 

Siu Sylvia Lee (Plenary Speaker) 

7 SIR-2.1, an HDAC, is Required To Maintain The Male Mating Potency In C. 

elegans 

Xiaoyan Guo, Luis rene Garcia 

8 LC-MS Proteomics Analysis Reveals Both Common and Unique Changes in 

the Proteome of Insulin/IGF-1 Receptor Mutant and Dietary Restricted C. 

elegans 

Geert Depuydt, Fang Xie, Vladislav Petyuk, Heather Brewer, Arne Smolders, Ineke Dhondt, Nilesh 

Shanmugam, David Camp II, Richard Smith, Bart Braeckman 

9 Characterization of Caenorhabditis Nematode Infecting Viruses 

Carl Franz, Marie-Anne Felix, Yanfang Jiang, Guoyan Zhao, Hilary Renshaw, Guang Wu, David 

Wang 

ix


10 Functions of MicroRNAs During Aging 

Alexandre de Lencastre, Frank Slack 

11 Integration of the Unfolded Protein and Oxidative Stress Responses through 

SKN-1/Nrf 

Kira Glover-Cutter, Stephanie Lin, T. Keith Blackwell 

12 Oxygen, temperature, and food: new insights into the role of environment in 

C. elegans aging 

Matt Kaeberlein (Plenary Speaker) 

13 The transcription factor HLH-30/TFEB regulates autophagy and modulates 

longevity in C. elegans 

Louis Lapierre, Malene Hansen 

14 HLH-30 is a new Transcription Factor involved in C. elegans Host Response 

triggered by S. aureus Infection 

Orane Visvikis, Nnamdi Ihuegbu, Lyly Luhachack, Amanda Wollenberg, Anna-Maria Alves, Gary 

Stormo, Javier Irazoqui 

15 Quantitative Proteomics Identifies SBP-1/SREBP as a General Transcriptional 

Regulator of Metabolic Pathways in C. elegans 

Julius Fredens, Kasper Engholm-Keller, Jakob Moeller-Jensen, Martin Roessel Larsen, Nils 

Færgeman 

16 Pathology Of The Aging Gonad Viewed By TEM 

David Hall, Angela Jevince, Ken Nguyen, Laura Herndon 

x 

Friday, July 13, 2012 - 1:45–5:30 pm 



Chairs: Ho Yi Mak and William Mair 

17 New Insights Into Understanding The Regulation Of Fat And Feeding 

Kaveh Ashrafi (Plenary Speaker), Katherine Cunningham, Aude Bouagnon, Liron Noiman 

18 Identification of DAF-16 Co-regulators with Tandem Affinity Purification and 

MudPIT 

Thomas Heimbucher, Zheng Liu, Andrea Carrano, Carine Bossard, Bryan Fonslow, Jonathan Yates, 

Tony Hunter, Andrew Dillin 

19 AMPK regulates a novel UPR-like response to mediate survival during 

nutrient stress in C. elegans 

Emilie Demoinet, Julie Mantovani, Richard Roy 

20 Pathways that regulate Reproductive Aging and Longevity 

Coleen Murphy (Plenary Speaker) 

21 A Novel Role of TGF-β Pathway in Dietary Restriction Induced Longevity 

Donha Park, Dara Lo, Charles Yang, Donald Riddle, Stefan Taubert


22 Mitochondrial Oxidative Stress in C. elegans Alters a Pathway with Strong 

Similarities to that of Bile Acid Biosynthesis and Secretion in Vertebrates 

Ju-Ling Liu, David Desjardins, Robyn Branicky, Luis B. Agellon, Siegfried Hekimi 

23 Surveillance of Core Cellular Processes as a Strategy for Xenobiotic and 

Pathogen Recognition 

Justine Melo, Gary Ruvkun 

24 Abstract withdrawn 

Saturday, July 14, 2012 - 8:30 am–12:30 pm 



Chairs: David Gems and Stefan Taubert 

25 Pinning Down MicroRNA Targets In Vivo 

Amy Pasquinelli (Plenary Speaker) 

26 Enhancing N-glycosylation Through Activation of the Hexosamine Pathway 

Improves ER Protein Folding Capacity and Slows Ageing. 

Nadia Storm, Martin Denzel, Adam Antebi 

27 ins-5 and ins-6 Promote Post-embryonic Development in Response to 

Feeding 

Yutao Chen, Ryan Baugh 

28 A New Class of Stress Resistance Genes 

Aimee Kao, Ayumi Nakamura, Meredith Judy, Anne Huang, Cynthia Kenyon 

29 Genetic Regulation of Age Pigment and Nile Red Accumulation in the 

Lysosome Related Organelle 

Alexander Soukas, Christopher Carr, Gary Ruvkun 

30 A Necrotic Cascade Accelerates Stress-Induced Death and Causes a Burst of 

Anthranilic Acid Fluorescence in C. elegans 

Cassandra Coburn, Parag Mahanti, Abraham Mandel, Filip Matthijssens, Bart Braeckman, Frank 

Schroeder, David Gems 

31 The real life of Caenorhabditis and their natural pathogens 

Marie-Anne Felix, (Plenary Speaker) Fabien Duveau, Tony Belicard 

32 Insulin Signaling and Dietary Restriction Differentially Regulate Glucose 

Metabolism to Impact C. elegans Healthspan 

Brian Onken, Monica Driscoll 

33 Exit of the Intracellular Pathogen Nematocida parisii from C. elegans Intestinal 

Cells 

Suzannah Szumowski, Kathleen Estes, Margery Smelkinson, Emily Troemel 

34 ULP-4 SUMO protease regulates mitochondria homeostasis during C. elegans 

development and mitochondrial stress 

Amir Sapir, Assaf Tsur, Thijs Thijs Koorman, Mike Boxem, Paul Sternberg, Limor Broday 

xi


35 The Diet of Worms: Expression of the agl-1 (Glycogen Debranching Enzyme) 

Embryonic Arrest Phenotype Depends on Maternal Diet 

Jeff Simske 

xii 

Saturday, July 14, 2012 - 1:45–5:30 pm 



Chairs: Arjumand Ghazi and Nils Færgeman 

36 Fatty acid desaturase activity regulates lipid droplet size 

Jennifer Watts (Plenary Speaker) 

37 The Lifespan Machine: A scalable, automated microscope increases the 

throughput and statistical quality of nematode lifespan and stress resistance 

assays 

Nicholas Stroustrup, Javier Apfeld, Walter Fontana 

38 Novel endogenous ligands of DAF-12 nuclear hormone receptor revealed by 

comparative metabolomics 

Parag Mahanti, Neelanjan Bose, Axel Bethke, Joshua Judkins, Joshua Wollam, Kathleen Dumas, 

Anna Zimmerman, Patrick Hu, Adam Antebi, Frank Schroeder 

39 Direct Detection of Mitochondrial Dysfunction by the Transcription Factor 

ATFS-1 

Cole Haynes 

40 Dissecting opposing age-dependent contributions of JNK signaling to stress 

resistance 

Kwame Twumasi-Boateng, Kuang-Hui Lee, Ali Salehpour, Michael Shapira 

41 A Genetic Screen for Novel DAF-16/FoxO Regulators 

Patrick Hu (Plenary Speaker), Kathleen Dumas, Albert Chen, Hung-Jen Shih, Chunfang Guo 

42 Interplay of Foreign and Endogenous Lectins in Innate Immunity of 

Caenorhabditis elegans 

Therese Wohlschlager, Alex Butschi, Katrin Stutz, Iain Wilson, Michael Hengartner, Markus Aebi, 

Markus Kunzler 

43 Cell-Specific Hypoxic Injury in C. elegans: Modeling the Ischemic Penumbra 

Chun-Ling Sun, Euysoo Kim, C. Michael Crowder 

44 Movement of RNA Silencing Between C. elegans Cells 

Antony Jose, Hai Le, Snusha Ravikumar, Sindhuja Devanapally 

45 WormBase 2012: Website Redesign 

Abigail Cabunoc, Norie de la Cruz, Adrian Duong, Maher Kassim, Xiaoqi Shi, Todd Harris, Lincoln 

Stein


Sunday, July 15, 2012 - 1:45–5:30 pm 



Chairs: Antony Jose and Javier Irazoqui 

46 Dynamic Neuroendocrine Signaling in C. elegans Behavioral Responses to 

Pathogenic Bacteria 

Dennis Kim (Plenary Speaker) 

47 The UPRER is a Cell Non-Autonomous Regulator of Stress Resistance and 

Longevity 

Rebecca Taylor, Andrew Dillin 

48 Interactions between 1-carbon cycle and lipid metabolism in C. elegans 

Amy Walker, Rene Jacobs, Jenny Watts, Veerle Rottiers, Anders Naar 

49 Novel approach in oxidative stress study by targeted ROS generation using a 

photosensitizer SuperNova in C. elegans 

Hiroshi SUZUKI, Donald Fu, Ippei Kotera, Po-An SU 

50 Natural Products that Suppress Protein Aggregation and Slow Aging 

Silvestre Alavez, Pedro Rodriguez, Maithili C. Vantipalli, David J. S. Zucker, Ida M. Klang Milena 

Price, Karla Mark, Gordon J. Lithgow (Plenary Speaker) 

xiii


xiv 

Friday & Saturday, July 13-14, 2012 - 7:30–9:30 pm 

Poster Sessions - Memorial Union, Great Hall/Reception Room (4th floor) 

Odd Numbered on Friday, Even Numbered on Saturday 

Topic: Aging 

Abstracts 51-77 

51 Expression-level Polymorphism for the Rec-8 Gene Underlies a Quantitative 

Trait Locus Governing Lifespan, Multiple Stress Resistances, and 

X-Chromosome Nondisjunction 

Srinivas Ayyadevara, Cagdas Tazearslan, Ramani Alla, Robert Shmookler Reis 

52 Effects of Dietary Restriction by Axenic Medium on Mitochondrial Function 

in Caenorhabditis elegans. 

Natascha Castelein, Berhanu Kassa, Bart Braeckman 

53 SGK-1 Extends Lifespan by Activating DAF-16/FoxO 

Albert Chen, Chunfang Guo, Kathleen Dumas, Travis Williams, Sawako Yoshina, Shohei Mitani, 

Kaveh Ashrafi, Patrick Hu 

54 Proteomic Changes Elicited by Metformin Treatment 

Wouter De Haes, Roel Van Assche, Steven Haenen, Bart Braeckman, Liliane Schoofs 

55 The p120RasGAP Family Member GAP-3 is a Novel Regulator of Dauer 

Arrest and Longevity 

Kathleen Dumas, Stephane Flibotte, Don Moerman, Patrick Hu 

56 Investigating the tissue-specific requirements for autophagy in C. elegans 

longevity mutants 

Sara Gelino, Malene Hansen 

57 Tumor suppressors and longevity in C. elegans 

Hakam Gharbi, Francesca Fabretti, Puneet Bharill, Bernhard Schermer, Thomas Benzing, Roman 

Ulrich Mueller 

58 Identification of a Novel Bacterial Species That Extends the Lifespan of 


Junhyeok Go, Kang-Mu Lee, Sang Sun Yoon 

59 The Role of Thioredoxin-1 (TRX-1) in Caenorhabditis elegans Aging 

Maria Gonzalez-Barrios, Juan Carlos Fierro-Gonzalez, Manuel Munoz, Peter Swoboda, Antonio 

Miranda-Vizuete 

60 Aging is a Determinant in Anoxia Stress Tolerance in Caenorhabditis elegans 

Jo Goy, Pamela Padilla 

62 Translational Effect of Hydrogen Sulfide on C. elegans 

Joseph Horsman, Dana Miller 

63 Roles of Specific daf-16/FoxO Isoforms in Dauer Regulation and Lifespan 

Control 

Chunfang Guo, Travis Williams, Kathleen Dumas, Sawako Yoshina, Shohei Mitani, Patrick Hu


64 Quantitative In Vivo Redox Sensors Uncover Oxidative Stress as an Early 

Event in Life 

Daniela Knoefler, Maike Thamsen, Martin Koniczek, Nicholas Niemuth, Ann-Kristin Diederich, 

Ursula Jakob 

65 Genes Acting Downstream of Sensory Neurons to Influence Longevity, Dauer 

Formation and Pathogen Responses in C. elegans 

Marta Gaglia, Dae-Eun Jeong, Eun-A Ryu, Dongyeop Lee, Seung-Jae Lee 

66 Age-dependent Alteration of Major Large Intestinal Granules in 


Kenji Nishikori, Takahiro Tanji, Eisuke Kuroda, Yuki Ueda, Hirohisa Shiraishi, Ayako Ohashi- 

Kobayashi 

67 Electrolyzed-reduced water confers increased resistance to environmental 

stresses and longevity in C. elegans 

Seul-Ki Park, Soon-Young Lee, Sang-Kyu Park 

68 A daf-16b-specific Mutation Extends C. elegans Lifespan 

Andy Polzin, Chunfang Guo, Sawako Yoshina, Shohei Mitani, Patrick Hu 

69 Molecular Mechanisms of C. elegans Germline Stem Cell Aging 

Zhao Qin, E. Jane Albert Hubbard 

70 Nutritional Deprivation in the Late Larval Stages of C. elegans Induces 

Developmental Diapause at Precise Checkpoints 

Adam Schindler, L Baugh, David Sherwood 

71 Shared Targets of TGF-β and Insulin/IGF-1 Signaling Regulate Reproductive 

Aging through Mechanisms Distinct from Somatic Aging Regulation 

Shijing Luo, Cheng Shi, Jasmine Ashraf, Coleen Murphy 

72 The Role of FAHD1 in the Aging of Caenorhabditis elegans 

Andrea Taferner, Haymo Pircher, Lucia Micutkova, Nektarios Tavernarakis, Pidder Jansen-Duerr 

73 Physical Interaction of Half ABC Transporters HAF-4 and HAF-9, Which Are 

Required for the Biogenesis of the Intestinal Lysosome-related Organelles in 


Takahiro Tanji, Kenji Nishikori, Hirohisa Shiraishi, Masatomo Maeda, Ayako Ohashi-Kobayashi 

74 Neurite Sprouting and Synapse Deterioration in the Aging C. elegans 

Nervous System 

Marton Toth, Ilija Melentijevic, Leena Shah, Aatish Bhatia, Kevin Lu, Amish Talwar, Haaris Naji, 

Carolina Ibanez-Ventoso, Piya Ghose, Angelina Jevince, Laura Herndon, Gyan Bhanot, Christopher 

Rongo, David Hall, Jian Xue, Monica Driscoll 

75 Identification of the Core Chaperone Network that Modulates Proteostasis 

in C. elegans 

Cindy Voisine, Kai Orton, Richard Morimoto 

76 The Conserved MicroRNA-80 Modulates C. elegans Longevity through 

Dietary Restriction 

Mehul Vora, Mitalie Shah, Jian Xue, Monica Driscoll 

xv


77 Supplemental cellular protection by a carotenoid astaxanthin extends 

lifespan via ins/IGF-1 signaling in C. elegans 

Sumino Yanase 

xvi 

Topic: Metabolism 

Abstracts 78-93 

78 The Role of Thioredoxin Reductase in Inorganic Selenium Metabolism in C. 

elegans 

Christopher Boehler, Roger Sunde 

79 Regulation of lipid storage and secretion: Genetics and Molecular Analysis 

Christopher Brey, Jun Zhang, Sanya Hashmi, Randy Gaugler, Sarwar Hashmi 

80 Investigation of Satiety Quiescence Signaling Using Automated Locomotion 

Assay and Hidden Markov Model Analysis to Identify Worm Behavioral States 

Thomas Gallagher, Leon Avery, Young-Jai You 

81 Circadian rhythms in metabolism, stress tolerance and pathogenesis: lessons 

from Caenorhabditis elegans. 

Maria Goya, Andres Romanowski, Maria Migliori, Sergio Simonetta, Diego Golombek 

82 Ceramide signal mediates antipsychotic drug-induced developmental delay 

and lethality in C. elegans. 

Limin Hao, Bruce Cohen, Edgar Buttner 

83 Functional Characterization of C. elegans N-acylethanolamine Biosynthetic 

Enzymes 

Neale Harrison, Ifedayo Victor Ogungbe, Matthew Gill 

84 The Mediator Subunit MED15/MDT-15 is a Conserved Transcriptional Coregulator 

in Lipid Homeostasis 

Nicole Hou, Donha Park, Stefan Taubert 

85 L1 longevity is determined by metabolic rate and that AMPK as a master 

regulator of metabolism controls 

Inhwan Lee, Amber Hendrix, Jennifer Yoshimoto, Jeongho Kim, Young-Jai You 

86 Proteomic Study and Marker Protein Identification of Caenorhabditis 

elegans Lipid Droplets 

Pingsheng Liu, Peng Zhang, Huimin Na 

87 WormSizer: High-Throughput Image Analysis of Nematode Size and Shape 

Brad Moore, James Jordan, Ryan Baugh 

88 Acetylcholine Dependent Starvation Signaling 

Robert Pollok, Leon Avery 

89 How to sense fasting : searching for the mechanism of energy homeostasis by 

IRE-1 

Jisun Shin, Hyungmin Moon, Jiwon Shim, Junho Lee


90 Pigment dispersing factor - a neuropeptidergic influence on metabolism and 

stress 

Liesbet Temmerman, Ellen Meelkop, Tom Janssen, Liliane Schoofs 

91 Ethanol Influence on Gonadal Development in C. elegans daf-18/PTEN 

Mutants 

Tim Wolf, Wenjing Qi, Ralf Baumeister 

92 Increased Levels of Hydrogen Peroxide Induce a HIF-1-dependent 

Remodeling of Lipid Metabolism in C. elegans 

Meng Xie, Richard Roy 

93 The Transmembrane Channel-like Protein TMC-1 Affects Adaptation to a 

Chemically Defined Medium in C. elegans 

Liusuo Zhang, L Rene Garcia 

Topic: Stress 

Abstracts 94-131, 170 

94 Screening for novel regulators of rnt-1 in stress response 

Soungyub Ahn, Junho Lee 

95 Screening Nuclear Receptors to Discover the Regulation of the Xenobiotic 

Stress Response 

Leah Blackwell, Amanda Marra, Andrew Davidson, Tim Lindblom 

96 Depletion of the Nascent Polypeptide-associated Complex in C. elegans 

Up-regulates ER Chaperone Expression and Engages the Unfolded Protein 

Response, Resulting in the Induction of Autophagy and Apoptosis 

Paul Arsenovic, Anthony Maldonado, Vaughn Colleluori, Tim Bloss 

97 Genetic analysis of the Unfolded Protein Response during pathogen infection 

in C. elegans 

Douglas Cattie, Kirthi Reddy, Claire Richardson, Dennis Kim 

98 BCAS2 is Essential for Drosophila Viability and Functions in Pre-mRNA 

Splicing 

Po-Han Chen, Yeou-Ping Tsao, Show-Li Chen 

99 Oxidative stress related PMK-1-HIF-1 signaling pathways in silver 

nanoparticles toxicity in C. elegans 

Jinhee Choi, Hyun - Jeong Eom, Jeong-Min Ahn 

100 Insulin-like signaling in the parasitic nematode Brugia malayi 

Kirsten Crossgrove, Brenda Garland, Peter Sackett 

101 Using Mathematical Models to Predict Gene Flow and Discover Gene 

Function 

Andrew Davidson, Marc-Andre LeBlanc, Megan Powell, Tim Lindblom 

102 EGL-9 Function is Required to Produce Viable Offspring from Animals 

Exposed to Chronic Hypoxia 

Jennifer Dennis, Pamela Padilla, Brent Little 

xvii


103 Analysis a Null Allele of the Heterochronic Gene lin-42, a period Homolog 

Theresa Edelman, Katherine McCulloch, Angela Barr, Christian Frokjaer-Jensen, Erik Jorgensen, 

Ann Rougvie 

104 SWI/SNF is Required to Maintain Memory of Adaptation to Hydrogen Sulfide 

Emily Fawcett, Dana Miller 

105 Diet & Environment Affect Oxygen-Deprivation Survival in C. elegans 

Anastacia Garcia, Pamela Padilla 

106 Transcriptional Regulation in the Oxidative Stress Response 

Grace Goh, Ada Kwong, Stefan Taubert 

107 Disruption of the ire-1/xbp-1 UPR Pathway Induces ER stress and Attenuates 

the Production and Processing of Secreted Proteins Such as Insulin 

Modi Safra, Cynthia Kenyon, Sivan Henis-Korenblit 

108 The Role of C. elegans BRAP-2 in Regulation of the Oxygen Radical 

Detoxification Response 

Queenie Hu, Lesley MacNeil, Marian Walhout, Terry Kubiseski 

109 Epigenetic regulation of stress response in C. elegans 

Moonjung Hyun, Young-Jai You 

110 The Role Of daf-2 Pathway In Primary, Secondary, And Delayed Hypoxic 

Injury 

Euysoo Kim, Chun-Ling Sun, Michael Crowder 

111 The Influence of Endoplasmic Reticulum Stress on the Dauer Developmental 

Decision in C. elegans 

Warakorn Kulalert, Dennis Kim 

112 PKC-2 in Peroxide mediated Stress and Aging 

Marianne Land, Charles Rubin 

113 High-throughput screening for small molecule modulators of SKN-1 

Chi Leung, Siobhan Malany, Andrew Deonarine, Ying Wang, Keith Choe 

114 Multisite phosphorylation fine-tunes SKN-1 activity by modulating 

interactions with WDR-23 and target DNA 

Chi Leung, Koichi Hasegawa, Keith Choe 

115 Functions of CLIC proteins in C. elegans 

Jun Liang, Cathy Savage-Dunn 

116 Mouse Nmnat1 protects C. elegans from hypoxic death 

Xianrong Mao, C. Michael Crowder 

117 Gene silencing based functional analysis of C. elegans cytochromes P450: roles 

in biotransformation, fat storage and eicosanoid formation 

Ralph Menzel, Christian Steinberg, Wolf-Hagen Schunck 

118 Deciphering the microRNA responses to High Temperature Stress 

Camilla Nehammer, Agnieszka Podolska, Konstantinos Kagias, Sebastian Mackowiak, Nikolaus 

Rajewsky, Roger Pocock 

xviii


119 Transmission of a Q/N-Rich Prion Domain Between C. elegans Tissues Causes 

an Extreme Form of Proteotoxicity 

Carmen Nussbaum-Krammer, Kyung-Won Park, Liming Li, Ronald Melki, Richard Morimoto 

120 The affect of carbohydrate diet, metabolism, germline function and age on 

oxygen deprivation response and survival in C. elegans 

Pamela Padilla, Anastacia Garcia, Jo Goy, Mary Ladage 

121 Understanding Hypoxia-dependent, HIF-independent Pathways in C. elegans 

Divya Padmanabha, Young-Jai You, Keith Baker 

122 Osmotic Stress Resistance and Cuticle Defects – Two Symptoms, One Cause 

Anne-Katrin Rohlfing 

123 Knockdown of Genes Involved in Basic Cellular Functions Impairs 

Mitochondrial ROS Stress Signaling to the Nucleus 

Eva Runkel, Shu Liu, Ralf Baumeister, Ekkehard Schulze 

124 The Effects of HIF-1 Over-Activation: Real-Time Assays for Toxin Response 

Jenifer Saldanha, Archana Parashar, Santosh Pandey, Jo Anne Powell-Coffman 

125 Exploring Natural Variation of Starvation Resistance and Growth Rate 

Moses Sandrof, Meghan Jobson, L. Ryan Baugh 

126 The Role of the Translation Machinery in Survival from Hypoxia 

Barbara Scott, Chun-Ling Sun, Xianrong Mao, Charles Yu, C. Michael Crowder 

127 The Role of the Ubiquitin-Proteasome System in the Formation of 

Polyglutamine Aggregates 

Gregory Skibinski, Lynn Boyd 

128 C. elegans as a Model to Study Drug-induced Mitochondrial Dysfunction 

Richard de Boer, Reuben Smith, Hans van der Spek, Stanley Brul 

129 Identification of pathways by which a peroxiredoxin influences stress 

resistance reveal (i) its importance for insulin/IGF1-like-signalling and (ii) new 

genes important for phase 2 detoxification gene expression, stress resistance 

and longevity 

Helen Crook, Monika Olahova, Elizabeth Veal 

130 Energy Metabolism Abnormality Of Ultraviolet Irradiation Sensitive Mutant 

Rad-8 In C. elegans 

Kayo Yasuda, Michihiko Fujii, Hitoshi Suda, Phillip Hartman, Takamasa Ishii, Naoaki Ishii 

131 Graphite Nanoplatelets and Caenorhabditis elegans: Insights from an in vivo 

Model 

Elena Zanni, Giovanni De Bellis, Maria Bracciale, Alessandra Broggi, Maria Santarelli, Maria 

Sarto, Claudio Palleschi, Daniela Uccelletti 

170 Dynamics of stress response across the worm unveils cross-tissue 

interactions 

Ronen Kopito, Christian Anderson, Erel Levine 

xix


xx 

Topic: Pathogenesis 

Abstracts 132-161, 169 

132 Cancer-like features could facilitate rapid intracellular growth of a natural 

intracellular parasite in C. elegans. 

Malina Bakowski, Amy Ma, Christopher Desjardins, Christina Cuomo, Emily Troemel 

133 Identifying a genetic basis to resistance against microsporidian parasites 

Keir Balla, Erik Andersen, Zhi Yan, Leonid Kruglyak, Emily Troemel 

134 Mapping natural variation in sensitivity to the Orsay virus in C. elegans wild 

isolates 

Tony Belicard, Marie-Anne Felix 

135 The Human Herpesvirus Type 1 Latency Associated Transcript Produces Egg 

Laying and Locomotion Defects in the Nematode C. elegans 

Ana Bratanich, Jesica Diogo 

136 The Conserved 1-Cys Peroxiredoxin, PRDX-6, has Diverse Roles in Stress 

Resistance, Innate Immunity and Aging 

Emma Button, Elizabeth Veal 

137 Shiga-like Toxin 1 Is Required Partly for The Pathogenicity of Escherichia coli 

O157:H7 in Caenorhabditis elegans 

Chang-Shi Chen, Ting-Chen Chou, Hao-Chieh Chiu, Cheng-Ju Kuo, Ching-Ming Wu, Wan-Jr Syu 

138 Leucobacter Strains Are Diverse Natural Pathogens of Caenorhabditis 

Laura Clark, Marie-Anne Felix, Maria Joao Gravato-Nobre, Jonathan Hodgkin 

139 Discriminating Pathogens from Innocuous Microbes: C/EBP Surveillance 

Immunity in C. elegans Intestinal Defense 

Tiffany Dunbar, Zhi Yan, Keir Balla, Margery Smelkinson, Emily Troemel 

140 The invertebrate lysozyme ILYS-3 aids bacterial disruption and acts in the 

intestine under non-autonomous pharyngeal control to protect against 

bacterial infection 

Maria Joao Gravato-Nobre , Jonathan Hodgkin 

141 Dissecting ERAD Component Function in a Motor Neuron Disease Model 

Angela Jablonski, Robert Kalb 

142 A Transmembrane Leucine-Rich Repeat Protein Important for Microsporidia 

Infection in C. elegans 

Robert Luallen, Malina Bakowski, Emily Troemel 

143 The redox sensor TRX-1: a potential regulator of signaling in C. elegans 

Katie McCallum, Danielle Garsin 

144 Functional Characterization of Thioredoxin 3 (TRX-3), a Caenorhabditis 

elegans Intestine-Specific Thioredoxin 

Maria Jimenez-Hidalgo, Cyril Leopold Kurz, Jose Rafael Pedrajas, Francisco Jose Naranjo-Galindo, 

Juan Cabello, Elamparithi Jayamani, Eleftherios Mylonakis, Juan Carlos Fierro-Gonzalez, Peter 

Swoboda, Antonio Miranda-Vizuete


145 Screening Potential Anthelmintic Compounds for Novel Activity 

Megan Gross, Olufadakemi Awoyinka, Michael Smith, M. Shahjahan Kabir, James Cook, Aaron 

Monte, Jennifer Miskowski 

146 Characterizing C. elegans behavior in response to E. faecalis 

Mona Gardner, Thomas Graciano, June Middleton, Edith Myers 

147 Exploring Antifungal Potential of CAMPs in the C. elegans Infection Model 

Massimiliano Olivi, Daniela Uccelletti, Maria Mangoni, Donatella Barra, Claudio Palleschi 

148 Using Bacterial Infection as a Tool to Dissect the Molecular Components of 

the Nematode Surface 

Delia O’Rourke, Rebecca Price, Dave Stroud, Jonathan Hodgkin 

149 Identification of the Transcriptional Targets of the PMK-1 p38-Dependent 

Transcription Factor ATF-7 

Daniel Pagano, Dennis Kim 

150 The Role of the G-protein Coupled Receptor FSHR-1 in the C. elegans Stress 

Response 

Amanda Miller, Hannah Anthony, Joseph Robinson, Shannon Hartley, Jennifer Powell 

151 Nematodes Living in Anoxic Conditions at a Deep-sea Methane Seep are 

Infected With Sexually Transmitted Parasitic Fungus-related Microsporidia 

Amir Sapir, Adler Dillman, Manuel Mundo-Ocampo, James Baldwin, Victoria Orphan, Paul 

Sternberg 

152 Key Residues of Cry5B Structure and Function: Mutagenesis by Alanine 

Scanning 

Jillian Sesar, Yan Hu, Sandy Chang, Arash Safavi, Raffi Aroian 

153 Caenorhabditis elegans Neutralizes Small Molecule Toxins Produced by 

Pseudomonas aeruginosa 

Gregory Stupp, Ramadan Ajredini, Arthur Edison 

154 Coprinopsis cinerea Lectins-mediated Toxicity against C. elegans 

Katrin Stutz, Alex Butschi, Silvia Bleuler-Martinez, Mario Schubert, Markus Aebi, Markus 

Kuenzler, Michael Hengartner 

155 Understanding the Molecular Underpinnings of Pathogen Recognition in C. 

elegans 

Kwame Twumasi-Boateng, Hae-Sung Kang, Michael Shapira 

156 Reactive oxygen species generated by BLI-3/Ce-Duox1 during infection 

triggers the activation of SKN-1 in C. elegans 

Ransome van der Hoeven, Katie McCallum, Melissa Cruz, Danielle Garsin 

157 TRPM Channels are Required for Clozapine’s Effects in C. elegans 

Xin Wang, Taixiang Saur, Bruce Cohen, Edgar(Ned) Buttner 

158 QTL Mapping of Differential Susceptibility to Bacteria in Caenorhabditis 

elegans 

Ziyi Wang, Michael Herman, Basten Snoek, Jan Kammenga 

xxi


159 C. elegans Acyl-CoA synthetase-3 And The Nuclear Receptor NHR-25 

Promote Epidermal Integrity And Resistance To Pathogens. 

Jordan Ward, Carole Couillault, Brendan Mullaney, Teresita Bernal, Marc Van Gilst, Kaveh Ashrafi, 

Jonathan Ewbank, Keith Yamamoto 

160 Genetic Mechanisms of Innate Immune Response: The interaction between 

Caenorhabditis elegans and the opportunistic pathogen Stenotrophomonas 

maltophilia 

Corin White, Vinod Mony, Brian Darby, Michael Herman 

161 Characterization of the Effects of Naturally Isolated Salmonella enterica 

Strains on Caenorhabditis elegans 

Amanda Wollenberg, Anna Maria Alves, Michael McClelland, Javier Irazoqui 

169 Characterizing in-host population dynamics of pathogenic bacteria during 

intestinal infection of C. elegans 

Ronen Kopito, Andrzej Nowojewski, Erel Levine 

xxii 

Topic: Small RNAs 

Abstracts 61, 162-168 

61 LEP-2/Makorin Promotes let-7 microRNA-mediated Terminal Differentiation 

in Male Tail Tip Morphogenesis 

R Antonio Herrera, Karin Kiontke, David Fitch 

162 Analysis Of mi-RNAS, Target Prediction Algorithms And Databases In C. 

elegans 

Hema Kasisomayajula, Frnklyn Bolander 

163 C. elegans rrf-1 Mutations Maintain RNAi Efficiency in the Soma in Addition 

to the Germline 

Caroline Kumsta, Malene Hansen 

164 Genetic requirements for viRNAs-mediated antiviral immunity in C. elegans 

Jeremie Le Pen, Alyson Ashe, Leonard Goldstein, Eric Miska 

165 Unifying Models of Biological Timers: A Molting Cycle Approach 

Gabriela Monsalve, Alison Frand 

166 C. elegans PRG-1 and piRNAs silence target transcripts through a secondary 

22G-siRNA pathway 

Alexandra Sapetschnig, Eva-Maria Weick, Marloes Bagijn, Leonard Goldstein, Amy Cording, Eric 

Miska 

167 MicroRNA Predictors of Longevity in C. elegans 

Zachary Pincus, Thalyana Smith-Vikos, Frank Slack 

168 A Genetic Suppressor Screen in Caenorhabditis elegans for Targets of 

Antipsychotic Drugs: Role of the Nicotinic Acetylcholine Receptor Homolog 

acr-7 

Taixiang Xu, Xin Wang, Limin Hao, Bruce Cohen, Edgar Buttner

Contact: ewbank@ciml.univ-mrs.fr 

Lab: Ewbank 


Building an integrated view of anti-fungal innate immunity 

Jonathan Ewbank 

Centre déImmunologie de Marseille-Luminy, INSERM, CNRS, Aix-Marseille 

Université , Marseille, France 

Our research focuses on how C. elegans responds to fungal infection, mainly using a 

natural pathogen, Drechmeria coniospora. Worms have a highly derived innate immune system, 

exemplified by the fact that they have no equivalent of NF-kappaB, central to immunity in 

many animal species. Nor do they have many of the receptors known from other species to be 

important for triggering host defenses. On the other hand, in common with most multicellular 

organisms, both plant and animal, C. elegans can produce antimicrobial peptides (AMPs) that 

contribute to pathogen resistance. We have applied forward and reverse genetics, proteomics, 

biochemistry, and cell biology to dissect the signaling pathways that control the expression of 

two main AMP families, the structurally-related nlp and cnc genes. 

Our recent results have given insights into the different steps of host defense: how infection 

is recognized, what signaling networks transduce this information and how the innate immune 

response is integrated into cellular and organismal physiology. 

Session 1 Keynote Speaker 

1


Metformin increases C. elegans lifespan by altering E. coli folate 

metabolism 

Filipe Cabreiro 1 , Catherine Au 1 , Kit-Yi Leung 2 , Nick Greene 2 , David Gems 1 

1 Institute of Healthy Ageing, University College London, London, UK, 2 Institute of 

Child Health, University College London, London, UK 

Metformin is the most widely prescribed drug for type II diabetes, and also increases 

lifespan in C. elegans and rodents, possibly by inducing a dietary restriction-like state. Worms 

are co-cultured with E. coli, which exerts complex nutritional and pathogenic effects on their 

host/predator affecting lifespan. In mammals, intestinal microbiota mediates effects of nutrition 

on host metabolic status, and risk of metabolic disease. We are investigating how metformin 

acts to increase worm lifespan and, perhaps, ameliorate metabolic disease. In the absence 

of E. coli, or on UV-irradiated or metformin-resistant E. coli, this drug only shortens lifespan. 

Moreover, using a range of E. coli strains, effects of metformin on worm lifespan correlate 

positively with its inhibitory effect on bacterial growth. This implies that E. coli mediates effects 

of metformin on worm lifespan. Metformin inhibits E. coli growth by impairing folate metabolism 

via a so-called “methyl trap” involving methionine synthase inhibition. Metformin effects on worm 

lifespan are phenocopied by the dihydrofolate reductase inhibitor trimethoprim (an antibiotic), 

but are independent of effects on bacterial proliferation. Thus, metformin has two effects on 

adult worms: a direct, life-shortening one (probably reflecting drug toxicity), and an indirect, 

life-extending effect promoted by bacterial metabolic alteration. The latter is mediated in the 

worm by a metabolic sensing pathway controlling the S-adenosyl-methionine/S-adenosylhomocysteine 

ratio. Life-extending effects of metformin involve sams-1 (S-adenosyl methionine 

synthetase), metr-1 (methionine synthase) and aak-2 (AMP-activated protein kinase). skn-1 

(homologous to mammalian Nrf2) and aak-2 also mediate the life-extending effects of metformin 

by protecting against drug toxicity. Consistent with this, the latter two mutants are hypersensitive 

to developmental retardation by metformin. Finally, elevated glucose, a risk factor for metabolic 

disease, abolishes life extension by metformin. In humans, side effects of metformin include 

gastrointestinal upset and folate deficiency. This, with our findings, suggests evolutionarily 

conserved bacterial mediation of metformin effects on host metabolism, and the therapeutic 

power of manipulating intestinal microbiota to assure metabolic health. 

Contact: F.cabreiro@ucl.ac.uk 

Lab: Gems 

2 

Session 1

Contact: kjdumas@umich.edu 

Lab: Hu 


The C. elegans Dosage Compensation Protein DPY-21 Regulates 

Dauer Arrest 

Kathleen Dumas1 , Stephane Flibotte2 , Don Moerman2 , Patrick Hu1 1 2 University of Michigan, Ann Arbor, MI, USA, University of British Columbia, 

Vancouver, BC, Canada 

In C. elegans, both reducing insulin/insulin-like growth factor signaling (IIS) and ablating 

the germline extend life span by promoting the translocation of DAF-16/FoxO to the nucleus. 

Nuclear DAF-16/FoxO induces transcriptional programs that promote longevity. The IIS pathway 

in C. elegans consists of conserved PI3K and Akt components that antagonize DAF-16/FoxO 

by promoting its cytoplasmic sequestration. We have discovered the EAK pathway, a novel, 

conserved pathway that inhibits DAF-16/FoxO. The EAK pathway acts in parallel to PI3K/Akt 

signaling to inhibit nuclear DAF-16/FoxO activity without promoting its translocation to the 

cytoplasm. How the EAK pathway inhibits DAF-16/FoxO is not known. 

To illuminate mechanisms by which the EAK pathway inhibits DAF-16/FoxO, we performed 

a genetic screen for suppressors of the eak-7;akt-1 dauer arrest phenotype (seak mutants). 

Among sixteen independent seak mutants isolated, three harbored distinct missense mutations 

in dpy-21, which encodes a conserved component of the dosage compensation complex (DCC) 

that represses X-chromosome gene expression in hermaphrodite animals. All three dpy-21 

mutations affect conserved residues in the C-terminus of the protein. SNP mapping indicated 

that the seak phenotype is linked to dpy-21 in all three mutants, and dpy-21 RNAi recapitulates 

the seak phenotype. Therefore, dpy-21 is likely a bonafide seak gene. 

To determine whether the effect of dpy-21 mutations on eak-7;akt-1 dauer arrest was due 

to disruption of the DCC, we performed RNAi knockdown of the ten known DCC components 

in eak-7;akt-1 double mutant animals. Whereas RNAi of sdc-1 and dpy-30 failed to suppress 

eak-7;akt-1 dauer arrest, RNAi of genes encoding the other eight DCC components suppressed 

eak-7;akt-1 dauer arrest significantly. Importantly, RNAi of dpy-27, which encodes the only 

condensin complex component that is specific to the DCC, strongly suppressed eak-7;akt-1 

dauer arrest. These results implicate multiple components of the DCC in the control of dauer 

arrest. Experiments are ongoing to determine whether the effect of DCC knockdown on dauer 

arrest is an indirect consequence of aberrant expression of X-linked or autosomal dauer 

regulatory genes as opposed to a direct effect of DCC proteins on DAF-16/FoxO target gene 

expression. 

Session 1 

3


Germline Stem Cells Regulate Somatic Proteostasis During 

Caenorhabditis elegans Adulthood 

Netta Shemesh, Nadav Shai, Anat Ben-Zvi 

Ben-Gurion University of the Negev, Beer-Sheva, Israel 

All cells rely on highly conserved protein folding and clearance pathways to detect 

and resolve protein damage and maintain protein folding homeostasis (proteostasis). The 

recognition that an age-associated imbalance in proteostasis is a potent contributor to the 

onset of neurodegenerative diseases stresses the need to understand how protein folding is 

regulated in a multi-cellular organism. We have noted that the ability of Caenorhabditis elegans 

to maintain proteostasis declines sharply following the onset of oocyte biomass production, 

suggesting that a restricted folding capacity may be linked to the onset of reproduction. To 

test this hypothesis, we monitored the effects of different sterile mutations on proteostasis 

maintenance in the soma of C. elegans. We find that germline stem cell (GSC) arrest rescued 

protein quality control, resulting in maintenance of robust proteostasis in different somatic 

tissues of adult animals. We further demonstrate that cell-nonautonomous signaling via kri-1, 

a key player in GSC-dependent regulation of fat metabolism and longevity, is a mediator of 

proteostasis maintenance in adulthood. We find that signaling through kri-1 and, specifically, the 

activity of LIPL-4, a lipase that is regulated by KRI-1, can uncouple germline proliferation from 

somatic proteostasis and prevent the switch between a robust and a limited state of proteostatic 

capacity in the soma. This decreases the age-dependent accumulation of damaged proteins 

and postpones the onset of age-dependent protein misfolding in a polyglutamine disease model. 

Contact: anatbz@bgu.ac.il 

Lab: Ben-Zvi 

4 

Session 1

Contact: ryan.baugh@duke.edu 

Lab: Baugh 


Transgenerational Effects of Starvation on Development, 

Reproduction and Lifespan: Bet-hedging on an Epigenetic Fitness 

Trade-off 

Meghan Jobson, L. Ryan Baugh 

Duke University, Durham, NC, USA 

Starvation during early human development has epigenetic effects that are thought to be 

adaptive if famine persists, and there may be transgenerational effects as well. Life in the 

wild is presumed to be feast or famine for C. elegans, suggesting that the worm has a robust 

epigenetic response to starvation. Our lab uses L1 arrest and recovery as a model to investigate 

nutritional control of development. We examined a variety of life history traits in well-fed animals 

following L1 arrest to characterize epigenetic effects of starvation. We show that development, 

reproduction and lifespan are all affected after recovery from L1 arrest and, remarkably, that 

these epigenetic effects persist for multiple generations. Development is delayed, producing 

smaller adults, and fertility is reduced, but stress resistance and lifespan increase. Egg-laying 

behavior is also affected, with a high frequency of internal hatching (i.e. ‘bagging’), revealing 

epigenetic control of reproductive behavior. Starvation causes a striking amount of phenotypic 

variation among isogenic individuals, and those that develop slowest are least fertile but most 

stress resistant. These most affected individuals live 50% longer, and they transmit the life 

span extension phenotype to their progeny as well as increased starvation resistance. Our 

work shows that environmental conditions and life history can have profound transgenerational 

epigenetic effects on several organismal traits including lifespan. In particular, we demonstrate 

epigenetic control of a fitness trade-off between reproduction and stress resistance in response 

to starvation, suggesting anticipation of stress. Furthermore, the resulting phenotypic variation 

among isogenic individuals is consistent with an evolutionary bet-hedging strategy to optimize 

fitness in fluctuating environmental conditions. 

Session 2 

5


Transcriptional Network Key to Longevity Determination and Stress 

Regulation 

Siu Sylvia Lee 

Cornell University, Ithaca, NY, USA 

The highly conserved transcriptional co-regulator HCF-1 is capable of coordinating many 

transcription and chromatin factor complexes and participates in a wide variety of biological 

processes. We previously identified the C. elegans hcf-1 null mutant to be long-lived and stress 

resistant. Our investigations revealed that HCF-1 modulates longevity and stress response by 

acting with the protein deacetylase SIR-2.1/SIRT1 to regulate the activity of DAF-16/FOXO. 

Interestingly, HCF-1 appears to also regulate SKN-1/NRF2 to specifically affect oxidative stress 

response. Our data suggest HCF-1 is an integral component of the transcriptional network key 

to longevity determination and stress regulation. 

Contact: sylvia.lee@cornell.edu 

Lab: Lee 

6 

Session 2 Plenary Speaker

Contact: xguo@bio.tamu.edu 

Lab: Garcia 


SIR-2.1, an HDAC, is Required To Maintain The Male Mating Potency In 

C. elegans 

Xiaoyan Guo 2 , Luis rene Garcia 2,1 

1 HHMI, 2 Texas A&M University, College Station, TX 

In a previous study (1), we carefully characterized that C. elegans male mating behavior 

significantly deteriorates at adult age day 3. Through direct mating behavior observations, 

Ca2+ imaging, and pharmacological tests, we found that the muscular components used for 

mating become more excitable as the males age. To further uncover the molecular mechanism, 

we found that sir-2.1, a histone deacetylase in C. elegans might be the link between the male 

mating behavior decay and the increase of the sex muscle excitability. Compared to wild type, 

sir-2.1(ok434) males mating potency prematurely decline: a significant drop is observed at 

adult age day 2, correlating with an obvious increase of sex muscle excitability. Furthermore, 

we observed that sir-2.1(ok434) males have a series of metabolism disorders: significantly 

more glycogen, fat and ATP are synthesized in sir-2.1(ok434) males. Those observations lead 

to the hypothesis that there is more ROS stress undergoing in sir-2.1 (ok434), which might be 

responsible for the increase of sex muscle excitability increase and mating potency decline. 

Indeed, we found that sir-2.1(ok434) males are more sensitive to the oxidative stress, paraquat. 

Meanwhile, for wild type males, feeding small amount of paraquat decreases the male mating 

potency at day 2 and increase the sex muscle excitability. 

1. Guo X, Navetta A, Gualberto DG, Garcia LR. Behavioral decay in aging male C. elegans correlates with 

increased cell excitability. Neurobiol Aging. 2012. 

Session 2 

7


LC-MS Proteomics Analysis Reveals Both Common and Unique 

Changes in the Proteome of Insulin/IGF-1 Receptor Mutant and 

Dietary Restricted C. elegans 

Geert Depuydt1 , Fang Xie2 , Vladislav Petyuk2 , Heather Brewer2 , Arne Smolders1 , Ineke 

Dhondt1 , Nilesh Shanmugam1 , David Camp II2 , Richard Smith2 , Bart Braeckman2 1 2 Biology Department, Ghent University, B-9000 Ghent, Belgium, Biological 

Sciences Division and Environmental Molecular Sciences Laboratory, Pacific 

Northwest National Laboratory, Richland, WA 99352, USA 

Impaired insulin/IGF-1 signaling (IIS) and dietary restriction are two well-characterized 

lifespan extending interventions that operate by (partially) independent mechanisms in C. 

elegans. Taking advantage of recent developments in quantitative LC-MS/MS based proteomics, 

we sought to uncover potentially universal, as well as condition-specific, proteomic changes 

that could underlie daf-2(e1370)- and dietary restriction-induced longevity. A most striking 

pattern in the proteome fingerprints of both long-lived IIS-mutant and DR worms is the overall 

decrease in the abundance of a large number of ribosomal proteins of both the large (60S) 

and small (40S) subunits. Consistently, we found decreased rates of protein synthesis in our 

long-lived worms. These results indicate that a general downregulation in mRNA translation 

rate is part of an adaptive response that allows daf-2 and DR worms to be long-lived. A second 

common pattern in these worms is the increased abundance of many muscle proteins, which 

we could attribute to an increase in relative, but not absolute, muscle biomass. In addition, 

increased mRNA levels of muscle-related genes and higher concentrations of branched-chain 

amino acids as a result of their reduced catabolism in daf-2, suggest C. elegans attempts 

to preserve muscle integrity in conditions of low nutrient availability. A most striking pattern 

in the daf-2 proteome profile is the strong upregulation of most core intermediary metabolic 

pathways (e.g. carbohydrate, fat, oxidative ATP generation), including several pathways that 

are reciprocally regulated. Despite this upregulation of the energy metabolic machinery, we 

found daf-2 animals fit a hypometabolic energy profile, similar to dauers, but retain the ability 

for strong activity bursts when necessary. 

Contact: Geert.Depuydt@ugent.be 

Lab: Braeckman 

8 

Session 2

Contact: franzcj@gmail.com 

Lab: Wang 


Characterization of Caenorhabditis Nematode Infecting Viruses 

Carl Franz 1 , Marie-Anne Felix 2 , Yanfang Jiang 1 , Guoyan Zhao 1 , Hilary Renshaw 1 , Guang 

Wu 1 , David Wang 1 

1 Washington University School of Medicine, Saint Louis, (MO), USA, 2 Institute of 

Biology of the Ecole Normale Superieure (IBENS), Paris, France 

Orsay virus and Santeuil virus, the first discovered viruses capable of naturally infecting 

the nematodes C. elegans and C. briggsae, respectively, were recently discovered by high 

throughput sequencing of wild Caenorhabditis strains. By similar analysis of another wild 

C. briggsae isolate, we have now discovered and sequenced the complete genome of 

another novel virus, Le Blanc virus, that shared less than 50% amino acid identity with Orsay 

and Santeuil viruses. All three viruses are most closely related to nodaviruses, which are 

positive sense RNA viruses with bipartite genomes. Comparison of their complete genomes 

demonstrated unique coding and noncoding features absent in known nodaviruses. Le Blanc 

virus, similar to Santeuil virus, was capable of infecting wild C.briggsae isolates but not the 

AF16 C. briggsae laboratory reference strain nor any tested C. elegans strains. In order to 

define the tissue tropism of nematode infection by Orsay, Santeuil and Le Blanc viruses, we 

developed immunofluorescence assays targeting proteins from each of the three viruses. 

Analysis of virally infected larval stage worms demonstrated that infection by all three viruses 

was localized to intestinal cells. Furthermore, the RNA dependent RNA polymerase and capsid 

proteins of Orsay virus exhibited distinct subcellular localization patterns. These findings identify 

a third novel virus and provide further characterization of the recently established viral infection 

system in Caenorhabditis nematodes. 

Session 2 

9


Functions of MicroRNAs During Aging 

Alexandre de Lencastre, Frank Slack 

Yale University, New Haven, CT, USA 

MicroRNAs (miRNAs) function to regulate gene expression during development in higher 

eukaryotes. Previous work in our lab has demonstrated that miRNAs of previously unknown 

function, such as miR-71, miR-238, miR-239 and miR-246 function during adulthood to promote 

or antagonize longevity and stress response in C. elegans (1). We found that these miRNAs are 

up-regulated in aging and genetically interact with components of the insulin signaling pathway 

and the DNA damage checkpoint response pathway. Together with our previous observation 

that mutations to the miRNA lin-4 and its target lin-14 significantly affect the lifespan of C. 

elegans (2), these results establish miRNAs as a new class of aging-associated genes, with 

the potential to interact with a wide range of aging pathways. 

In order to understand the biological function of these age-associated miRNAs, we have 

begun characterizing the factors downstream as well as upstream of these miRNAs that mediate 

their function. We have shown by genetic epistasis that the insulin-signalling and the DNA 

damage response pathways interact with miR-71 and miR-239. In order to characterize the 

detailed molecular identities of pathway genes that may transduce these miRNAs’ functions, 

we have surveyed the mRNA expression levels of multiple genes in these pathways in the 

genetic background of aging-associated miRNA mutants. We have found significantly deregulated 

expression of candidate targets genes in these pathways that are also predicted to 

be direct targets of these miRNAs. Similarly, we have also begun characterizing the identity 

of upstream factors that regulate the expression of our age-associated miRNAs. We have 

evidence that suggests that 2 well-known transcription factors regulate the expression of specific 

aging-associate miRNAs and suggest a possible function for these miRNAs as mediators of 

organismal response to environmental stress. Given the high conservation of aging pathways 

and miRNAs across species, it is likely that insights uncovered by this research will have high 

relevance towards our understanding of aging in higher organisms and humans. 

References: 

1. de Lencastre A. et al., Curr Biol. 20, 1-10 (2010). 

2. Boehm M., Slack FJ., Science. 310, 1954-7 (2005). 

Contact: alexandre.delencastre@yale.edu 

Lab: Slack 

10 

Session 2

Contact: keith.blackwell@joslin.harvard.edu 

Lab: Blackwell 


Integration of the Unfolded Protein and Oxidative Stress Responses 

through SKN-1/Nrf 

Kira Glover-Cutter, Stephanie Lin, T. Keith Blackwell 

Joslin Diabetes Center and Harvard Medical School, Boston, MA, USA 

C. elegans SKN-1 (ortholog of mammalian Nrf1/2/3) is critical for oxidative and xenobiotic 

stress defense, and maintenance of proteasome activity. SKN-1 also promotes longevity, and 

is important for lifespan extensions associated with reduced growth signaling (Insulin/IGF- 

1-like, TORC1, TORC2) and dietary restriction. SKN-1 regulates genes involved in various 

biological processes, and mobilizes distinct responses to different stresses or signals, including 

perturbations in protein synthesis. We now report that SKN-1 plays an essential role in the 

unfolded protein response (UPR) to stress in the endoplasmic reticulum (ER), where secretory 

and membrane proteins are synthesized, processed, and folded. SKN-1 is important for ER 

stress resistance, and is required for ER stresses to induce expression of core UPR signaling 

and transcription factors (XBP-1, ATF-5, IRE-1, HSP-4/BiP), along with downstream genes. 

A number of these genes are direct transcriptional targets of SKN-1. SKN-1 cooperates with 

UPR transcription factors at downstream regulatory targets, including its own gene, and its 

expression is induced by ER stress. SKN-1 also associates with the ER, suggesting a possible 

signaling role. Surprisingly, the UPR signaling apparatus is required for SKN-1 to accumulate 

in nuclei and activate downstream genes in response to oxidative stresses. Impairment of 

UPR signaling increases oxidative stress sensitivity, consistent with its importance for SKN-1 

functions. The data show that SKN-1 is a key UPR factor and has a broad role in maintaining 

protein homeostasis, and that its functions are modulated by interactions with other stressresponse 

transcription factors, a paradigm that may explain how SKN-1 mounts responses 

that are tailored to different stress situations. They also indicate that signaling from the ER 

plays a licensing and possibly detection role in oxidative stress responses, a relationship that 

may be important because of the centrality of redox status to ER function. 

Session 2 

11


Oxygen, temperature, and food: new insights into the role of 

environment in C. elegans aging 

Matt Kaeberlein 

University of Washington, Department of Pathology, Seattle, WA, United States 

Aging is controlled by a complex interaction between environmental and genetic factors. 

The most studied environmental modulator of longevity is nutrient availability, with dietary 

restriction known to extend lifespan in species from yeast to monkeys. In addition to food, 

oxygen and temperature are also known to be important environmental factors in determining 

adult lifespan in C. elegans. Here I will describe our recent efforts to understand how each of 

these environmental components interacts with known genetic modifiers of aging, including 

insulin-like signaling, mRNA translation, and the hypoxic response. I will also describe ongoing 

studies to define the mechanisms of lifespan extension from stabilization of the hypoxic response 

transcription factor, HIF-1, under normoxic conditions. 

Contact: kaeber@uw.edu 

Lab: Kaeberlein 

12 


Contact: lapierre@burnham.org 

Lab: Hansen 


The transcription factor HLH-30/TFEB regulates autophagy and 

modulates longevity in C. elegans 

Louis Lapierre, Malene Hansen 

Sanford-Burnham Medical Research Institute 

The cytosolic degradation process of autophagy has emerged as a key mechanism 

required for lifespan extension in C. elegans, yet the underlying regulatory mechanisms remain 

unclear. The mammalian transcription factor TFEB was recently found to coordinately upregulate 

several genes involved in both the formation of the autophagosome (i.e., the vesicle 

sequestering material for degradation) and in lysosomal processing (i.e., compartment where 

active degradation takes place). In this study, we asked if the nematode ortholog of TFEB, 

called HLH-30, is a functional homolog of mammalian TFEB. 

To investigate this hypothesis, we analyzed the function of HLH-30 in long-lived, germlineless 

glp-1 mutants. We previously reported that glp-1 mutants display increased autophagy, 

and require autophagy genes to live long (Lapierre et al., Current Biology, 2012). We found 

that glp-1 animals, along with an increased expression of hlh-30, showed significantly elevated 

mRNA levels of worm orthologs for multiple TFEB autophagy and lysosomal targets. Notably, 

the promoters of these target genes contain conserved binding sites for HLH-30. We also 

observed that glp-1 animals subjected to hlh-30 RNAi showed decreased induction of targets, 

as well as reduced numbers of GFP::LGG-1 autophagosomal puncta, indicating that HLH-30 

regulates autophagy in long-lived C. elegans. 

Finally, we asked if hlh-30 plays a role in longevity, as previously reported for multiple 

autophagy genes. We found that RNAi knockdown of hlh-30 in adult glp-1 animals significantly 

shortened their long lifespan, while not affecting the lifespan of wild-type animals. In addition, 

we observed a similar trend in another longevity model, the daf-2 insulin/IGF-1 receptor 

mutants, suggesting that hlh-30 plays a broader role in lifespan extension. Collectively, our 

findings indicate that HLH-30 is a novel longevity-modulating transcription factor, which displays 

functional similarity to its mammalian counterpart TFEB. 

Session 2 

13


HLH-30 is a new Transcription Factor involved in C. elegans Host 

Response triggered by S. aureus Infection 

Orane Visvikis 1 , Nnamdi Ihuegbu 2 , Lyly Luhachack 1 , Amanda Wollenberg 1 , Anna-Maria 

Alves 1 , Gary Stormo 2 , Javier Irazoqui 1 

1 Program of Developmental Immunology, Massachusetts General Hospital, 

Boston (MA), USA, 2 Center for Genome Sciences, Washington University, St. 

Louis (MO), USA 

The human pathogen Staphylococcus aureus can infect and kill Caenorhabditis elegans. 

Previous microarray analysis showed that S. aureus triggers a pathogen-specific transcriptional 

host response, which appears to be regulated by Toll-like receptor-independent sensing of 

pathogen-associated molecular patterns (PAMPs). To identify components that orchestrate the 

C. elegans host response, we performed bioinformatic analysis and identified evolutionarily 

conserved DNA motifs that are over-represented in the promoters of S. aureus induced 

genes (SAIGs). One such motif corresponds to the HLH-30 binding E-box. hlh-30 expression 

analysis by RT-qPCR revealed a 2-fold up-regulation upon infection. Additionally, we generated 

transgenic animals over-expressing HLH-30::GFP under its own promoter. HLH-30::GFP protein 

was found to accumulate in the nucleus upon infection, consistent with the hypothesis that 

HLH-30 is a transcription factor involved in the host response to S. aureus infection. 

To test this hypothesis, we performed RNA-seq to determine the downstream target genes 

of HLH-30 in uninfected and infected animals. Of 825 SAIGs identified in wild-type animals, 

637 SAITs (77%) were not induced in hlh-30(-) animals, confirming that HLH-30 plays a 

key role in the C. elegans host response to S. aureus. GO annotation of these 637 HLH-30 

dependent SAIGs revealed enriched terms related to antimicrobial factors. We used RT-qPCR 

and in vivo reporter analysis to confirm that HLH-30 controls induction of antimicrobial factors 

during infection. Consistently, we found that hlh-30(-) mutants exhibit enhanced susceptibility 

to S.aureus-mediated killing. Therefore, we suspect that the transcriptional defect observed 

in hlh-30(-) animals is biologically significant for host defense. Interestingly, we found that hlh- 

30(-) animals also display enhanced susceptibility to other C. elegans pathogens (S.enterica, 

P. aeruginosa, E. faecalis) suggesting that HLH-30 might also regulate the host response to 

these three pathogens. We also found that HLH-30 regulates expression of stress and aging 

genes. Consistently, we found that hlh-30(-) mutants are short-lived on non pathogenic food, 

and exhibit enhanced susceptibility to heat-shock and starvation, but not to oxidative stress. 

Altogether, these data indicate that HLH-30 is a major transcription factor that can control 

a biologically significant transcriptional host response to stresses such as S. aureus infection. 

Contact: ovisvikis@partners.org 

Lab: Irazoqui 

14 

Session 2

Contact: nils.f@bmb.sdu.dk 

Lab: Færgeman 


Quantitative Proteomics Identifies SBP-1/SREBP as a General 

Transcriptional Regulator of Metabolic Pathways in C. elegans 

Julius Fredens, Kasper Engholm-Keller, Jakob Moeller-Jensen, Martin Roessel Larsen, 

Nils Færgeman 

University of Southern Denmark, Odense, Denmark 

Stable isotope labeling by amino acids combined with mass spectrometry is a widely used 

methodology to quantitatively examine metabolic and signaling pathways in yeast, fruit flies, 

plants, cell cultures and mice. We have recently shown that C. elegans can be completely 

labeled with heavy-labeled lysine by feeding worms on prelabeled lysine auxotroph Escherichia 

coli for just one generation, and used this combined with high resolution mass spectrometry to 

identify novel genes regulated by nuclear hormone receptor 49 (Fredens et al., 2011, Nature 

Methods). We have used this methodology to examine how the multicellular organism C. 

elegans responds to knock down of SBP-1, a basic helix-loop-helix (bHLH) transcription factor 

homologous to the mammalian Sterol Regulatory Element Binding Proteins (SREBP), which is 

known as a master regulator of expression of lipogenic genes in eukaryotes. We have identified 

and quantified several thousands proteins, and among these identified several proteins that 

either become up-or down regulated in response to RNAi against SBP-1. As expected, several 

of the down-regulated proteins we identified are involved in the biosynthesis of fatty acids and 

glycerolipids, however, our results also indicate that SBP-1 regulate the transcription of genes 

involved in ceramide synthesis. Additionally, we identified a large number of proteins involved 

in carbohydrate- and amino acid metabolism to be down regulated upon SBP-1 knock down. 

Collectively, our findings suggest that SBP-1 not only regulate the expression of lipogenic genes, 

but also the expression of amino acid and carbohydrate metabolism. We therefore hypothesize 

that SBP-1 is a general transcriptional regulator of metabolic pathways in C. elegans. 

Session 2 

15


Pathology Of The Aging Gonad Viewed By TEM 

David Hall, Angela Jevince, Ken Nguyen, Laura Herndon 

Albert Einstein College of Medicine, Bronx, NY USA 

The Caenorhabditis elegans germline and somatic gonad undergo complex changes 

during larval development and achieve peak mature function during the first several days of 

adult life. After about 6 days of adult life, the animal’s reproductive capabilities begin to decline 

sharply. We used electron microscopy to characterize these unique age-related changes in 

the C. elegans germline and have concentrated on two ages, 10 and 18 days. Our findings 

suggest that initially the distal gonad arm becomes much shorter, but otherwise seems intact 

and the germline may still undergo some mitotic divisions. Between days 7-10 of adulthood, the 

wild type animal adopts an emo phenotype characterized by an accumulation of endomitotic 

oocytes in the proximal gonad arm. Egg laying fails and the uterine contents become trapped 

by the closed vulva, sometimes including a few fertilized embryos. By 10 days, we see multiple 

“haploid” oocytes undergoing acrosomal activation without being fertilized, since all sperm 

are exhausted. After activation, these oocytes do not form an eggshell, but gradually enlarge, 

undergoing nuclear endoreduplication to produce large masses of chromatin, surrounded by 

complex cytoplasm, first filling the uterus and then moving backwards into the ovary. Aging 

germline cells within the ovary and uterus are thus mixed with retained embryonic tissues 

that together can swell into a rigid mass centered at the midbody. We are in the process of 

determining whether the course of gonad decline is related to the decline in other tissues and 

if animals with longer healthspans and better body movement show less dramatic changes 

in their gonad. 

Contact: david.hall@einstein.yu.edu 

Lab: Hall 

16 

Session 2

Contact: kaveh.ashrafi@ucsf.edu 

Lab: Ashrafi 


New Insights Into Understanding The Regulation Of Fat And Feeding 

Kaveh Ashrafi, Katherine Cunningham, Aude Bouagnon, Liron Noiman 

University of California San Francisco, San Francisco, CA, United States 

Serotonergic regulation of fat content and feeding behavior has been studied intensively 

for understanding the basic neurociruitry of energy balance in various organisms and as a 

therapeutic target for human obesity. Its underlying molecular mechanisms still remain poorly 

understood. In C. elegans, serotonin signaling regulates fat content, food intake behavior as 

well as a number of other behaviors. We have discovered that serotonergic regulation of feeding 

can be initiated by the chemosensory ADF neurons. A signaling relay comprised of the SER-5 

receptor, AMP-activated kinase, and glutamatergic signaling links serotonergic signaling from 

the ADF chemosensory neurons to the pharyngeal nervous system of the animal to modulate 

pumping rate. SER-5 mediated regulation of AMPK occurs in previously uncharacterized 

neurons that are the sole site of function of hlh-34, the C. elegans counterpart of human SIM1, 

a transcription factor associated with obesity. These findings highlight the deep evolutionary 

origins of feeding regulatory mechanisms that operate in the mammalian hypothalamus. 

Interestingly, the feeding relay described above does not play a role in serotonergic regulation of 

fat content. Instead, another serotonergic relay comprised of a distinct set of neurally expressed 

serotonergic receptors signal to peripheral pathways to determine whether energetic resources 

should be directed to fat storage or fat oxidation pathways. As such, fat content is not simply 

a secondary consequence of food intake but regulated through neuroendocrine pathways 

that function independent of feeding regulatory mechanisms. We have discovered that these 

feeding-independent, fat regulatory pathways can be acted upon by heavily-used herbicides 

and other pollutants that are pervasive in the environment. This challenges the prevalent 

dogma that obesity is primarily a behavioral issue arising from either excessive caloric intake 

or reduced energy expenditure. 

Session 3 Plenary Speaker 

17


Identification of DAF-16 Co-regulators with Tandem Affinity 

Purification and MudPIT 

Thomas Heimbucher 1 , Zheng Liu 1 , Andrea Carrano 1 , Carine Bossard 1 , Bryan Fonslow 2 , 

Jonathan Yates 2 , Tony Hunter 1 , Andrew Dillin 1 

1 The Salk Institute for Biological Studies, La Jolla, CA, USA, Howard Hughes 

Medical Institute, Glenn Center for Aging Research, 2 The Scripps Research 

Institute, La Jolla, CA 

The FoxO transcription factor DAF-16 regulates a wide range of organismal functions: 

it is involved in C. elegans development and reproduction, in stress response and life span 

regulation. Association of DAF-16 with diverse binding partners might be crucial for mediating 

these heterogeneous functions. To identify DAF-16 regulators we established a biochemical 

approach to purify DAF-16 associated proteins. DAF-16 was fused to various epitop-tags. On the 

basis of a reporter assay it was analyzed whether tagged DAF-16 versions were transcriptionally 

active. Their activity was further assessed by their ability to rescue phenotypes of a daf-16 

null mutant. A functional tagged DAF-16 variant was used to generate a transgenic worm line. 

DAF-16 protein complexes were isolated by tandem affinity purification and potential DAF-16 

binding partners were identified by tandem mass-spectrometry (MudPIT). In an additional 

reporter based screen DAF-16 co-regulators were validated. Their potential roles in dauer 

formation, stress resistance and longevity are currently being pursued. We will discuss their 

identity and potential functions in insulin/IGF-1 signaling. 

This work was supported in part by the Austrian Science Fund (FWF, grant J2734), by a 

grant from NIH, and by the Glenn Center for Aging Research. 

Contact: theimbucher@salk.edu 

Lab: Dillin 

18 

Session 3

Contact: emilie.demoinet@mcgill.ca 

Lab: Roy 


AMPK regulates a novel UPR-like response to mediate survival during 

nutrient stress in C. elegans 

Emilie Demoinet, Julie Mantovani, Richard Roy 

McGill University, Montreal, Canada 

To enhance survival during periods of prolonged nutrient stress, many organisms execute 

developmental or reproductive diapause, which are reversible states of developmental 

dormancy. When growth conditions are suboptimal, Caenorhabditis elegans can arrest its 

development and execute a diapause like state. The best characterized of these are the first 

larval stage (L1) and dauer diapause. The C. elegans L1 arrest is a response to an insufficient 

level of nutrient to initiate postembryonic development, whereby development is suspended 

and environmental stress resistance is increased without obvious morphological modification. 

Wild type L1 hatchlings can normally survive up to 2 weeks in the absence of food under these 

conditions. We have shown that maximal survival in the L1 diapause requires aak-2, one of 

the 2 homologues of the alpha subunit of AMP-activated protein kinase (AMPK). AMPK is a 

metabolic master switch that is activated in response to various nutritional and stress signals. 

Its main function is to maintain cellular energy homeostasis by enhancing energy generating 

pathways, while blocking energy-consuming processes. We found that larvae that lack AMPK 

(aak(0)), are compromised for protein folding allowing aggregates to accumulate in the L1 

larvae, leading to their premature death after 5 days. The addition of glucose, delays aggregate 

accumulation and partially rescues survival. A similar accumulation of unfolded protein is 

observed in starved wild type L1 larvae just prior to death, which is delayed following glucose 

addition, while increasing their survival twofold. Accumulation of misfolded protein activates a 

highly conserved adaptive signaling cascade known as the unfolded protein response (UPR), 

which, when activated, can lead to adaptation or death. We have found that in the presence of 

an energetic stress, a previously uncharacterized UPR-like response involving novel effectors 

becomes activated to ensure organismal survival. Based on genetic and cell biological data, we 

suggest that AMPK regulates this response to prolong survival in the diapause until favorable 

energy conditions are restored. 

Session 3 

19


Pathways that regulate Reproductive Aging and Longevity 

Coleen Murphy 

Princeton University, Princeton, NJ, United States 

The understanding of the regulation of early aging is likely to be particularly helpful in 

improving quality of life. To that end, we study not only life span, but also such early aging 

phenotypes as loss of reproductive capacity. While the daf-2 Insulin/IGF-1-like signaling 

pathway and daf-16/FoxO are critical regulators of both of these phenotypes, other factors are 

emerging as regulators of specific aspects of aging. For example, TGF-beta dauer signaling 

affects longevity, but not reproductive span, while TGF-beta Sma/Mab signaling regulates 

reproductive aging but not longevity. Both autonomous and non-autonomous activities play a 

role in regulating and coordinating these pathways’ regulation of their transcriptional targets 

as well as their final phenotypic outputs. 

Contact: ctmurphy@princeton.edu 

Lab: Murphy 

20 


Contact: dpark@cmmt.ubc.ca 

Lab: Taubert 


A Novel Role of TGF-β Pathway in Dietary Restriction Induced 

Longevity 

Donha Park 1,2 , Dara Lo 1 , Charles Yang 1 , Donald Riddle 2 , Stefan Taubert 1 

1 Centre for Molecular Medicine and Therapeutics, University of British Columbia, 

Vancouver, BC, Canada, 2 Michael Smith laboratories, University of British 

Columbia, Vancouver, BC, Canada 

Transforming growth factor β (TGF-β) signaling plays a pivotal role to regulate cell 

proliferation, apoptosis, organ development and cancer metastasis. The downstream effector 

of TGF-β signaling, Smad proteins, interact with variety of partner proteins to achieve their 

function. To better understand Smad signaling, we performed immunoprecipitation (IP) of C. 

elegans DAF-8/R-Smad followed by mass spectrometry and identified the TGFβI receptor DAF- 

1 and HID-1 (High Temperature induced Dauer) as a novel DAF-8 interacting proteins. Others 

previously showed that HID-1 interacts physically with the E3 ubiquitin ligase WWP-1, which 

is required for dietary restriction (DR)-induced life span extension. To test whether HID-1 also 

affects longevity, we determined the life spans of hid-1 mutants and of worms over-expressing 

hid-1 in ad libitum (AL) and DR conditions. The hid-1 mutants showed a shortened adult life 

span, whereas hid-1 overexpression extended life span in AL and DR conditions. Furthermore, 

we found that over-expression of the TGFβI receptor daf-1 (daf-1oe) also extended worm life 

span in DR conditions, and this life span extension was dependent on hid-1. RNAi against skn- 

1/bZIP or pha-4/FoxA transcription factors only partially suppressed the daf-1oe mediated life 

span extension, indicating that TGF-β regulates DR-induced life span in parallel to skn-1 and 

pha-4. Furthermore, daf-7/TGFβ1 transcript and DAF-1 protein levels were maintained in DR 

conditions but decreased in AL fed worms over time, indicating that DR conditions may lead 

to sustained TGF-β signaling. Lastly, because mobilization of stored lipids may be affected in 

DR, we quantified the expression of several lipid metabolism genes. We found that several lipid 

β-oxidation genes, including daf-22, were induced by DR in daf-7 dependent manner, and that 

DR failed to extend the life span of daf-22 mutants. Overall, our results suggest that TGF-β 

signaling plays an important role in DR-induced life span extension, possibly be controlling 

lipid metabolism genes. 

Session 3 

21


Mitochondrial Oxidative Stress in C. elegans Alters a Pathway with 

Strong Similarities to that of Bile Acid Biosynthesis and Secretion in 

Vertebrates 

Ju-Ling Liu1 , David Desjardins1 , Robyn Branicky1,2 , Luis B. Agellon1 , Siegfried Hekimi1 1 2 McGill University, Montreal, Canada, MRC Laboratory of Molecular Biology, 

Cambridge, UK 

Mammalian bile acids (BAs) are oxidized breakdown products of cholesterol whose 

amphiphilic properties serve in lipid and cholesterol uptake. BAs also act as hormonelike 

substances that regulate metabolism. The C. elegans clk-1 mutants sustain elevated 

mitochondrial oxidative stress and display a slow defecation phenotype that is sensitive to 

the level of dietary cholesterol. We found that: 1) The defecation phenotype of clk-1 mutants 

is suppressed by mutations in tat-2, identified in a previous unbiased screen for suppressors 

of clk-1. TAT-2 is homologous to ATP8B1, a flippase required for normal BAs secretion in 

mammals. 2) The phenotype is suppressed by cholestyramine, a resin that binds BAs. 3) The 

phenotype is suppressed by the knock-down of C. elegans homologues of BA-biosynthetic 

enzymes. 4) The phenotype is enhanced by treatment with BAs but not by other detergents. 

5) Lipid extracts from C. elegans contain an activity that mimics the effect of BAs on clk-1 and 

the activity is more abundant in clk-1 extracts. 6) clk-1 and clk-1; tat-2 double mutants show 

altered cholesterol content. 7) The clk-1 defecation phenotype is enhanced by high dietary 

cholesterol and this effect requires TAT-2. 8) Suppression of clk-1 by tat-2 is rescued by BAs, 

and this requires dietary cholesterol. 9) The clk-1 phenotypes, including the level of activity 

in lipid extracts, are suppressed by antioxidants and enhanced by depletion of mitochondrial 

superoxide dismutases. Our observations suggest that C. elegans synthesizes and secretes 

molecules with properties and functions that resemble that of BAs. These molecules act in 

cholesterol uptake and their level of synthesis is up-regulated by mitochondrial oxidative 

stress. Future investigations should reveal whether these molecules are in fact BAs, which 

would suggest the unexplored possibility that the elevated oxidative stress that characterizes 

the metabolic syndrome might participate in disease processes by affecting the regulation of 

metabolism through BAs synthesis. 

Contact: ju-ling.liu@mail.mcgill.ca 

Lab: Hekimi 

22 

Session 3

Contact: jmelo@molbio.mgh.harvard.edu 

Lab: Ruvkun 


Surveillance of Core Cellular Processes as a Strategy for Xenobiotic 

and Pathogen Recognition 

Justine Melo, Gary Ruvkun 

Massachusetts General Hospital, Boston, MA USA 

The nematode C. elegans is attracted to nutritious bacteria and is repelled by pathogens 

and poisons. The basis for discrimination between benign and harmful food sources is poorly 

understood. We show that RNAi and toxin-mediated disruption of core cellular activities, 

including protein translation, oxidative respiration, and protein degradation, stimulate behavioral 

avoidance of normally attractive bacteria. RNAi of these and other essential processes 

induced expression of drug detoxification and innate immune reporters in the absence of 

toxins or pathogens, suggesting that disruption of a single cellular process may be sufficient 

to trigger protective behavioral and physiological defenses. Disruption of core processes in 

individual tissues (such as the intestine or hypodermis) was sufficient to stimulate aversion 

behavior, revealing a neuroendocrine axis of control that additionally involved Jnk kinase and 

serotonin signaling circuits. We propose that surveillance pathways overseeing core cellular 

activities allow animals to recognize and reject poisonous food sources, including microbial 

pathogens that deploy toxins to sabotage vital host functions. Such a strategy should prove 

resilient to pathogen co-evolution and confer resistance to pathogens with which a host has 

no evolutionary history. 

Session 3 

23


Abstract Withdrawn 

Contact: haynesc@mskcc.org 

Lab: Haynes 

24 

Session 3

Contact: apasquinelli@ucsd.edu 

Lab: Pasquinelli 


Pinning Down MicroRNA Targets In Vivo 

Amy Pasquinelli 

UCSD, La Jolla, CA, USA 

MicroRNAs (miRNAs) regulate gene expression by guiding Argonaute proteins to specific 

target mRNA sequences. Identification of bona fide miRNA target sites in animals is challenged 

by uncertainties regarding the base-pairing requirements between miRNA and target as well 

as the location of functional binding sites within mRNAs. To address these problems on a 

genome widescale, we developed a biochemical and computational strategy aimed at isolating 

and analyzing endogenous mRNA target sequences bound by the Argonaute protein ALG-1 in 

Caenorhabditis elegans. C. elegans provides several advantages for identifying miRNA target 

sites in vivo: a single Argonaute protein, ALG-1, is largely responsible for miRNA function, a 

viable alg-1 genetic mutant control allows for extensive elimination of background sequence 

noise, a short but well-established list of miRNA targets expected to be bound by ALG-1 at 

discrete positions is available, and the in vivo binding context of endogenous ALG-1:RNA 

interactions in live animals is preserved. Using cross-linking and ALG-1immunoprecipitation 

coupled with high-throughput sequencing (CLIP-seq), we identified extensive ALG-1 interactions 

with specific 3’UTR and coding exon sequences and discovered features that distinguish 

miRNA complex binding sites in 3’UTR from other genic regions. Furthermore, these studies 

revealed that Argonaute also binds non-codingRNAs and point to a novel role for Argonaute 

in the regulation of miRNA biogenesis. 


25


Enhancing N-glycosylation Through Activation of the Hexosamine 

Pathway Improves ER Protein Folding Capacity and Slows Ageing. 

Nadia Storm, Martin Denzel, Adam Antebi 

Max Planck Institute, Cologne, Germany 

Organismal ageing is the progressive loss of cellular homeostasis - including protein 

homeostasis, which comprises all processes maintaining a functional proteome. The endoplasmic 

reticulum (ER) is the site of protein synthesis for all secreted and membrane proteins, and 

the ER protein folding fidelity is closely monitored. Proper ER protein folding depends on 

chaperones, and requires N-glycosylation of the nascent peptide chain. Insufficient folding 

capacity triggers a stress response pathway, termed the unfolded protein response (UPR). The 

UPR signaling pathway is critical for normal C. elegans lifespan and for lifespan extension via 

the insulin signaling pathway. We hypothesized that improving ER stress resistance might result 

in lifespan extension. To identify novel mutations that improve ER protein folding we carried 

out a developmental drug resistance screen. After chemical mutagenesis, we selected for 

resistance to tunicamycin, which interferes with ER protein folding by inhibiting N-glycosylation. 

Next, we analyzed the lifespan of the tunicamycin resistant mutants. We found that increasing 

metabolite flux through the hexosamine pathway (HP) by gain-of-function mutations of the 

pathway’s key enzyme, glucosamine-fructose 6-phosphate aminotransferase (gfat-1), results 

in ER stress resistance and lifespan extension. The HP provides UDP-N-acetylglucosamine 

(UDP-GlcNAc) that is required in the first step of N-glycan synthesis, which is inhibited by 

tunicamycin. Tunicamycin resistance resulting from GFAT-1 hyperacitvation could be mimicked 

by feeding wild type C. elegans with HP intermediates and was DAF-16/FOXO-independent. 

GFAT-1 hyperactivation or exposure to UDP-GlcNAc precursors reduced the expression of 

UPR target genes during ER stress, as seen in the gain-of-function mutants, suggesting an 

elevated threshold for UPR activation resulting from increased folding capacity. Increased HP 

metabolite flux further alleviated pathology in nematode models of proteotoxic stress, such as 

polyglutamine expansion, a model for Huntington’s disease. These data, together with GFAT-1’s 

high degree of conservation makes the HP a potential target for the treatment of age-related 

proteotoxic diseases in humans. 

Contact: nstorm@age.mpg.de 

Lab: Antebi 

26 

Session 4

Contact: yutao.chen@duke.edu 

Lab: Baugh 


ins-5 and ins-6 Promote Post-embryonic Development in Response to 

Feeding 

Yutao Chen, Ryan Baugh 

Department of Biology and IGSP Center for Systems Biology, Duke University, 

Durham, NC, USA 

Animals must coordinate development with fluctuating nutrient availability. Nutrient availability 

governs post-embryonic development in C. elegans: larvae that hatch in the absence of food 

do not initiate post-embryonic development but enter “L1 arrest” (or “L1 diapause”) and can 

survive starvation for weeks. Insulin-like signaling is a key regulator of L1 arrest and recovery. 

However, the C. elegans genome encodes 40 putative insulin-like peptides (ILPs), and there is 

evidence that they can function to promote development (“agonists”) or arrest (“antagonists”). 

We used the nCounter platform to measure high-resolution mRNA expression dynamics for all 

40 ILPs in response to feeding and fasting in recently hatched L1 larvae. Expression of 18 of 

the ILPs is significantly affected by switching nutrient conditions. We classified several ILPs 

as candidate agonists or antagonists based on expression. Destabilized YFP reporter gene 

analysis confirms nutritional control of transcription and reveals the intestine as the primary 

site of transcriptional regulation. Phenotypic analysis during recovery from L1 arrest reveals 

that ins-5 and ins-6 deletion mutants have retarded developmental dynamics affecting M and 

V-lineage cell divisions. This is the first phenotype reported for ins-5, and the role of ins-6 in L1 

recovery is consistent with its role in dauer exit. Other ILPs that regulate dauer formation, life 

span or germ line proliferation do not have detectable effects on L1 development. Together these 

results suggest specificity of ILPs function, even among agonists. By combining expression 

and phenotypic analysis, we identified 2 ILPs that promote rapid post-embryonic development 

in response to feeding, and we report additional functional predictions based on expression 

analysis. 

Session 4 

27


A New Class of Stress Resistance Genes 

Aimee Kao, Ayumi Nakamura, Meredith Judy, Anne Huang, Cynthia Kenyon 

University of California San Francisco, San Francisco, CA 

Animals have many ways of protecting themselves against stress; for example, they can 

induce stress-protective pathways or they can kill damaged cells via apoptosis. How the 

choice between these different options is made is not well understood. Here we show that C. 

elegans mutations that block the normal course of programmed cell death confer resistance 

to a specific set of environmental stressors: heat, ER and osmotic stress. Surprisingly, ced-3 

caspase mutations that block apoptosis; ced-1 and other engulfment mutations that prevent 

apoptotic cell removal, and progranulin (pgrn-1) mutations that accelerate dying cell removal, 

all increased stress resistance. Because it is a gene that is associated with multiple diseases 

in humans, including neurodegeneration, auto-immunity and cancer, we characterized pgrn-1 

mutant-associated stress resistance in detail. We found that the ER stress resistance elicited 

by pgrn-1 mutations exhibits genetic dependency on the unfolded protein response (UPR) 

factors IRE-1 and PEK-1, the MAP kinase PMK-1 and the stress-related transcription factor 

DAF-16/FOXO. Mutations in pgrn-1 and the ced genes may induce a common pathway, since 

they do not exhibit additive effects. To explain these findings, we propose that C. elegans has a 

surveillance system that detects perturbations in the normal cell death pathway and responds 

to them by inducing an alternative, organism-wide stress-protective pathway. These genes 

represent a new class of stress response regulators. 

Contact: akao@memory.ucsf.edu 

Lab: Kenyon/Kao 

28 

Session 4

Contact: asoukas@chgr.mgh.harvard.edu 

Lab: Ruvkun/Soukas 


Genetic Regulation of Age Pigment and Nile Red Accumulation in the 

Lysosome Related Organelle 

Alexander Soukas 1 , Christopher Carr 2 , Gary Ruvkun 1 

1 Massachusetts General Hospital, Boston, MA, USA, 2 Massachusetts Institute of 

Technology, Cambridge, MA, USA 

When fed to C. elegans, the vital dye Nile red highlights the cellular compartment known 

as the lysosome related organelle. While work by us and others indicates that this cellular 

compartment is distinct from canonical lipid droplets, the lysosome related organelle is well 

implicated in aging and metabolism as it is the site of accumulation of lipofuscin, or age pigment. 

We have found that both autofluorescence and feeding Nile red accumulate to a greater 

extent in short-lived C. elegans, and are therefore seem to be markers of progeria. To test this 

systematically, we have conducted large-scale genetic and genomic screens for altered feeding 

Nile red accumulation andautofluorescence. ~80 genes have been confirmed to alter Nile red 

accumulation, and we have examined these using RNAi and quantitative, high-throughput 

microscopy in genetic backgrounds which have altered age pigment accumulation. The results 

begin to shed light on the complex genetics underlying age pigment formation and accumulation 

and mutants obtained from forward genetics demonstrate that it is possible to genetically 

separate feeding Nile red accumulation from autofluorescent age pigment accumulation. The 

gene networks identified may shed light on fundamentals of the aging process as well as 

regulation of the lysosome related organelle and its role in aging and metabolism. 

Session 4 

29


A Necrotic Cascade Accelerates Stress-Induced Death and Causes a 

Burst of Anthranilic Acid Fluorescence in C. elegans 

Cassandra Coburn 1 , Parag Mahanti 2 , Abraham Mandel 1 , Filip Matthijssens 3 , Bart 

Braeckman 3 , Frank Schroeder 2 , David Gems 1 

1 University College London, London, UK, 2 Cornell University, Ithaca, NY, USA, 

3 Ghent University, Ghent, Belgium 

Under UV light, C. elegans gut granules (which are lysosome-related organelles) emit 

intense blue fluorescence. It has been suggested that the fluorescent material is lipofuscin, a 

heterogeneous aggregate of damaged proteins and lipids, that can accumulate with age within 

the lysosomes of mammalian cells. Autofluorescence increases with age in worm cohorts and 

so has commonly been used as a biomarker of aging. Lipofuscin accumulation in aging worms 

would be consistent with the notion that aging is caused by the accumulation of molecular 

damage. However, several observations imply that the blue fluorescent substance in worms 

is not lipofuscin. We have observed that oxidative stress does not increase blue fluorescence 

levels. Moreover, when individual worms are monitored throughout life, blue fluorescence 

only increases at the point of death (“death fluorescence”). Death fluorescence is also seen 

when young worms are killed. To identify the blue fluorophore we compared wild type (N2) 

with glo-1(zu437) (Gut granule LOss) mutants, which also do not exhibit death fluorescence, 

using a 2D NMR-based comparative metabolomic approach. This identified an anthranilic acid 

glucosyl ester and its 3’-phosphorylated derivative as the source of the blue fluorescence. 

Anthranilic acid is derived from tryptophan by action of the kynurenine pathway, where the 

rate limiting enzyme is tryptophan 2,3-dioxygenase (TDO). RNAi knockdown of the putative 

TDO C28H8.11 abrogated both gut granule and death fluorescence. (This provides a useful 

tool to aid studies of fluorescent reporters of gut-expressed genes, which can be masked by 

gut granule fluorescence). Our work has shown that death fluorescence is generated by a 

systemic cascade of cellular necrosis. We are currently investigating the role of this cascade, 

and of the kynurenine pathway, in aging and death. Our findings show that blocking necrosis 

or anthranilate synthesis extends lifespan in stressed animals. This suggests that systemic 

necrosis and the associated burst of anthranilate production can hasten organismal death. 

Contact: david.gems@ucl.ac.uk 

Lab: Gems 

30 

Session 4

Contact: felix@biologie.ens.fr 

Lab: Felix 


The real life of Caenorhabditis and their natural pathogens 

Marie-Anne Felix1 , Fabien Duveau1 , Tony Belicard1 1Institute of Biology of the Ecole Normale Supérieure, CNRS-Inserm-ENS, 46 rue 

d’Ulm, 75230 Paris cedex 05, France, 1Institute of Biology of the Ecole Normale 

Supérieure, CNRS-Inserm-ENS, 46 rue d’Ulm, 75230 Paris cedex 05, France 

C. elegans is a major laboratory model organism, yet its life and variation in the wild are 

little known. Especially, other organisms occurring in the habitats where C. elegans feeding 

stages are found are likely to be important players in its ecology, as potential food, pathogens 

or predators. 

We find natural populations of Caenorhabditis species in rotting vegetal matter, such 

as fruits, flowers and stems. Population counts may span a range of 1 to over 10,000 

Caenorhabditis individuals in a single fruit or stem. Some populations with an intermediate 

census size (10-1000) contained no dauer larvae at all, whereas larger populations always 

included some larvae in the pre-dauer or dauer stages. It appears thus likely that C. elegans 

undergoes a population boom upon encountering a favorable rotting substrate, separated by 

periods of migration in the dauer stage. 

In our surveys in France, C. elegans and C. briggsae were found to co-occur on the same 

substrates. We followed their respective spatio-temporal distribution in an apple orchard over 

four years and found a seasonal distribution that matches their temperature preference in the 

laboratory in competition experiments. 

Wild Caenorhabditis were observed to often harbor a live bacterial flora in their intestinal 

lumen. In some instances, the flora proliferates and a large bacterial plug obstructs the whole 

intestinal tract. 

Pathogens provide strong and changing selection pressures. Natural pathogens are thus 

relevant to study the defense systems of C. elegans and their potentially rapid evolution, and 

may provide interesting models of co-evolution between host and pathogen. Several natural 

pathogens of C. elegans were isolated, including microsporidia, bacteria, fungi and recently 

the first viruses that infect C. elegans or C. briggsae (Félix, Ashe, Piffaretti et al. PLoS Biol. 

2011). Different C. elegans wild isolates show widely different sensitivity to the Orsay virus, as 

assayed by viral load upon infection. A genome-wide association study of Orsay virus sensitivity 

in a worldwide set of C. elegans isolates indicates one major locus segregating in the species 

(see abstracts by T. Belicard et al. and J. Le Pen et al.). 

Thanks to the many colleagues who helped this work, especially the labs of Dave Wang and Eric Miska, 

Emily Troemel, Jonathan Hodgkin, Nathalie Pujol, Buck Samuel and all fellow samplers! 


31


Insulin Signaling and Dietary Restriction Differentially Regulate 

Glucose Metabolism to Impact C. elegans Healthspan 

Brian Onken, Monica Driscoll 

Rutgers University 

A major goal of aging research is to understand the underlying relationship between 

nutritional intake, metabolism, and healthy aging. Low-glycemic index diets have been shown 

to reduce risk of age-related metabolic diseases such as diabetes and cardiovascular disease, 

and reduced caloric intake via dietary restriction increases healthspan across species. One 

potential approach for supporting healthy aging is via interventions that engage healthspanpromoting 

metabolism. 

In Caenorhabditis elegans, adding excess glucose to the growth medium shortens 

lifespan [1, 2], while inhibiting the glycolytic enzyme hexokinase with the glucose analog 

2-deoxyglucose increases lifespan [1]. We have shown that disrupting genes encoding two 

other glycolytic enzymes that catalyze unidirectional, irreversible reactions in glycolysis 

lengthens Caenorhabditis elegans median lifespan, induces large gains in youthful locomotory 

ability, and triggers a fluorescent biomarker that distinguishes a healthy metabolic state. 

Conversely, disrupting counterpart unidirectional gluconeogenic genes decreases nematode 

healthspan. In investigating potential longevity-related pathways that might impinge upon 

glucose metabolism, we found that disrupting glycolytic genes increases healthspan through 

the FOXO transcription factor DAF-16, which is also required for the increased lifespan seen 

with lowered levels of insulin signaling, and which is downregulated by increased glucose 

availability [2]. Strikingly, we also found that gluconeogenic activity is specifically required for 

increased healthspan under dietary restriction, and that the SKN-1 transcription factor, which 

is required for the beneficial effects of dietary restriction [3], is also needed for the healthspan 

effects seen with decreased gluconeogenesis. These results provide evidence for an intriguing 

new paradigm: breakdown of glucose via glycolysis negatively impacts healthy aging through 

insulin signaling and DAF-16, while dietary restriction engages the reciprocal gluconeogenic 

pathway to promote healthspan via SKN-1. Our observations support that healthspan might be 

optimized via dietary, pharmacological, or genetic interventions that increase gluconeogenic 

activity or decrease glycolysis. 

1. Schulz TJ, Zarse K, Voigt A, Urban N, Birringer M, et al. (2007). Cell Metab 6: 280-293. 

2. Lee SJ, Murhpy CT, Kenyon C (2009). Cell Metab 10: 379-391. 

3. Bishop NA, Guarente L (2007). Nature 447: 545-549. 

Contact: onken@biology.rutgers.edu 

Lab: Driscoll 

32 

Session 4

Contact: sszumows@ucsd.edu 

Lab: Troemel 


Exit of the Intracellular Pathogen Nematocida parisii from C. elegans 

Intestinal Cells 

Suzannah Szumowski, Kathleen Estes, Margery Smelkinson, Emily Troemel 

University of California San Diego, San Diego, (CA), USA, University of California 

San Diego, San Diego, (CA), USA 

Microsporidia comprise a diverse phylum of fungal-related pathogens that infect a broad 

range of hosts, including insects and humans. As obligate intracellular parasites, microsporidia 

are dependent on their hosts for replication. Although they likely usurp many host processes, 

very little is known about the mechanisms of pathogenesis used by these ubiquitous microbes. 

Recently we found that the microsporidia Nematocida parisii reorganizes the host C. elegans 

actin cytoskeleton and terminal web prior to making a non-lytic exit from host cells. We found 

that N. parisii spores exit from the apical side of intestinal cells into the lumen, and that they are 

free of host membrane after exit. By studying how N. parisii exits from cells while minimizing 

damage to the host we expect to learn about key mechanisms of microsporidia transmission, 

as well as intestinal cell biology and intracellular trafficking. 

Our previous studies indicated that actin was required for N. parisii exit from intestinal 

cells, but we did not know the underlying mechanism. We now show that actin forms distinct 

“coats” on spores localized near the apical membrane. The number of actin coats in an animal 

is positively correlated with the number of spores that are shed. In addition, animals with 

actin-coated spores are more contagious than animals without actin-coated spores. Thus, 

we believe that actin-coated spores are exiting the host, and we are developing methods to 

image this process in vivo. So far, this process strongly resembles “kiss and coat” exocytosis 

where fusing membranes trigger actin polymerization in order to stabilize exiting cargo that 

is large or insoluble. 

Consistent with exocytic membrane topology, we observe intracellular host membrane 

around microsporidia prior to exit. Early during infection, microsporidia appear to be in direct 

contact with the cytoplasm, but later in infection EM analysis shows host membrane surrounding 

the pathogen. Thus, we believe that during development microsporidia steal intracellular 

membrane from the host. We hypothesize that this membrane comes from the mitochondria, 

based on imaging and analysis of mitochondrial mutants. In this way, microsporidia appear 

to usurp host processes in order to proceed through their life cycle and exit non-lytically from 

host cells. 

Session 4 

33


ULP-4 SUMO protease regulates mitochondria homeostasis during C. 

elegans development and mitochondrial stress 

Amir Sapir1 , Assaf Tsur2 , Thijs Thijs Koorman3 , Mike Boxem3 , Paul Sternberg1 , Limor 

Broday2 1Howard Hughes Medical Institute and Division of Biology, California Institute of 

Technology, Pasadena, CA 91125, USA, 2Department of Cell and Developmental 

Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel, 

3Developmental Biology, Utrecht University, Utrecht 3584, The Netherlands 

Mitochondria energy production and metabolism must be tightly and dynamically regulated 

to meet the different energetic and metabolic requirements of normal physiology, aging, and 

stress. Our understanding of the molecular mechanisms controlling these condition-dependent 

modulations of mitochondria activity, however, remains rudimentary at best. We hypothesize 

that post translational modification of mitochondrial proteins by organelle-specific effectors is 

taking place for a global regulation of mitochondria homeostasis. To address this hypothesis, 

we combined RNAi screening with protein localization and bioenergetics studies in C. elegans 

. We screened different members of the ubiquitin or SUMO effectors known to regulate protein 

post-translational modification. Focusing on the SUMO pathway, we identified a predicted 

SUMO protease, ulp-4, and found it to exhibits a complex age related and mitochondrial stressdependant 

expression and recruitment to the mitochondria of body wall muscles. To identify the 

transcription factors regulating ulp-4 expression, we conducted a small scale RNAi screen of 

candidate transcription factors known to function during stress and aging. We Identified atsf-1, 

a transcription factor that is activated by mitochondrial stress, as a regulator of ulp-4 stressdependent 

expression. In concurrence with ULP-4 mitochondrial localization, ulp-4 mutant 

worms exhibit a strong age dependent attenuation of muscle activity and abnormal mitochondria 

morphology presumably stemming from a reduction of mitochondria activity. ULP-4 protein 

localization into inner organelle domains supports a role of ULP-4 in regulating matrix proteins. 

To identify the mitochondrial targets of ULP-4, we screened C. elegans two-hybrid libraries and 

found association with phi-50, an orthologous gene of human 3-hydroxy-3-methylglutaryl CoA 

synthase that functions in the metabolic switch of mitochondria toward stress and starvation 

induced ketogenesis. Our results are emerging toward a regulatory pathway in which one of the 

molecular readouts of various environmental and physiological stressors is atsf-1 dependent 

ulp-4 expression in the body wall muscles. This expression is followed by ULP-4 protein 

recruitment to the mitochondria matrix where it may regulate the sumoylation state of PHI-50 

to support the metabolic switch toward mitochondrial stress-induced ketogenesis. 

Contact: amirsa@caltech.edu 

Lab: Broday 

34 

Session 4

Contact: jsimske@metrohealth.org 

Lab: Simske 


The Diet of Worms: Expression of the agl-1 (Glycogen Debranching 

Enzyme) Embryonic Arrest Phenotype Depends on Maternal Diet 

Jeff Simske 

Rammelkamp Center, Cleveland (OH), USA 

Previous analysis of agl-1 demonstrated that reduction in agl-1 activity results in reduced 

activity of AMPK, presumably though inhibition of AMPK via branched glycogen (limit dextrin) 

binding to the AMPKβ subunit AAKB-1 and/orAAKB-2. An ongoing challenge in studying agl-1 

mutants has been a mysterious loss of phenotype. Ultimately it was revealed that phenotypic 

expression depends on bacterial diet. Specifically, agl-1 mutants grown on freshly seeded, 

live OP50 display little embryonic arrest. Conversely, when grown on UV-killed OP50, agl-1 

hermaphrodites produce almost 100% arrested embryos. Similar agl-1 phenotypes are observed 

when grown on glucose or glycerol plates seeded with fresh OP50. A similar connection between 

bacterial viability and agl-1 phenotype was also observed when the drug metformin was tested 

for the ability to suppress agl-1 phenotypes through AMPK activation. When plated on media 

containing metformin, growth of OP50 itself is attenuated, and the phenotype of agl-1 mutants 

is enhanced. Conversely, metformin present in UV-killed bacterial plates or in glucose plates 

is able to suppress agl-1 phenotypes, but does not prevent bacterial growth in the presence 

of elevated glucose. Notably, bacteria grown on glucose or metformin+glucose are different in 

consistency than OP50 on normal NGM plates. These results suggest that metformin and dietary 

supplements influence agl-1 phenotypes primarily, but not exclusively through their effect on 

the bacterial food source. To test whether metformin exclusively acts via diet, metformin was 

injected directly into the pseudocoelom or gonad of agl-1 mutants grown on UV-killed OP50; 

agl-1 phenotypes were mildly suppressed. Furthermore, unlike UV-killed bacteria, live bacteria 

+ metformin diet resulted in animals with reduced brood size, and a pale, sickly appearance. 

Thus metformin affects worm physiology both through bacteria-dependent and independent 

pathways. Interestingly, the dietary maternal effect is reversible: when agl-1 hermaphrodites 

laying arrested embryos are shifted from dead or glucose-supplemented bacteria to live OP50, 

embryos hatch after a day or so and hermaphrodites shifted from ‘permissive’ diet to UV-killed 

bacteria generate dead embryos in a similar time-span. In all experimental conditions tested, 

severity of agl-1 phenotype correlates with reduction in AMPK activity. Ongoing research is 

focused on determining the metabolic factors that suppress agl-1 phenotypes. 

Session 4 

35


Fatty acid desaturase activity regulates lipid droplet size 

Jennifer Watts 

Washington State University, Pullman, WA, United States 

Fatty acid desaturation regulates membrane functions as well as fat storage in animals. C. 

elegans contains all of the enzymes required to synthesize long-chain polyunsaturated fatty 

acids, including arachidonic and eicosapentaenoic acid, from acetyl-CoA. The first double bond 

in a saturated fatty acyl chain is inserted by the D9 desaturases, also known as stearoyl-CoA 

desaturases (SCDs). C. elegans fat-6;fat-7 double mutants cannot catalyze the D9 desaturation 

of 18:0, leading to worms with high levels of 18:0 and a deficiency of C20 PUFAs. Similar to 

SCD1 knockout mice, these mutants have low fat stores and elevated rates of fat oxidation. 

Visualization of fat stores in the fat-6;fat-7 double mutants revealed small size droplets 

compared to wild type. We have constructed triple mutant strains in order to combine high fat 

mutants, such as daf-2, with the low fat SCD mutants. We found that droplet size resembles 

the fat-6;fat-7 in all triple mutant combinations, implying that SCD activity is necessary for the 

formation of large-sized lipid droplets. While most triple mutant strains have reduced fat stores 

as well as small lipid droplets, daf-2;fat-6;fat-7 triple mutants are able to store higher levels 

of triacyglycerols, even though the lipid droplet size is small. These studies reveal a specific 

role of stearoyl-CoA desaturase in regulating lipid droplet size. 

Contact: jwatts@wsu.edu 

Lab: Watts 

36 


Contact: stroustr@fas.harvard.edu 

Lab: Fontana 


The Lifespan Machine: A scalable, automated microscope increases 

the throughput and statistical quality of nematode lifespan and stress 

resistance assays 

Nicholas Stroustrup, Javier Apfeld, Walter Fontana 

Harvard Medical School 

Survival assays can provide evidence of a gene or environment’s role in aging and 

stress resistance. The interpretability of these widely-used experiments hinges crucially on 

the accuracy and precision with which measurements can be acquired. To address current 

limitations in the throughput, statistical power, and replicability of manual survival assays, we 

have developed an automated system for the acquisition and analysis of C. elegans mortality 

data. Our goal for this technology is not only to automate and improve the accuracy of the 

standard methodology, but also to remain low-cost and scalable. 

We present our recent experiences operating a microscope consisting of fifty flatbed 

scanners, which together monitor 30,000 individuals across 800 agar plates and 2.5 square 

meters of agar lawn, imaged every fifteen minutes at 8 um resolution. Our automated software 

analyzes this large volume of data to identify the death times of individual worms based on 

their movement, with a focus on subtle, late-life postural changes. Our toolset allows rapid 

visual validation of automated results, a critical step for the routine production of statistically 

rigorous mortality data. 

We discuss our results from a focused, high-throughput thermotolerance screen, as well as 

a high-resolution analysis of the lifespan of several insulin/IGF pathway mutants. We present 

our characterization of the strengths and limitations in sensitivity and reliability of C.elegans 

lifespan and stress resistance assays. We hope to spread our technology as a means for 

increasing the consistency and reproducibility of survival data between labs, and to support the 

accumulation of a self-consistent body of demographic aging data in the C. elegans community. 

Session 5 

37


Novel endogenous ligands of DAF-12 nuclear hormone receptor 

revealed by comparative metabolomics 

Parag Mahanti1 , Neelanjan Bose1 , Axel Bethke1 , Joshua Judkins1 , Joshua Wollam3 , 

Kathleen Dumas2 , Anna Zimmerman1 , Patrick Hu2,5 , Adam Antebi3,4 , Frank Schroeder1 1Boyce Thompson Institute and Department of Chemistry and Chemical Biology, 

Cornell University, Ithaca, (NY), USA, 2Life Sciences Institute, University of 

Michigan, Ann Arbor, (MI), USA, 3Max Planck Institute for Biology of Aging, 

Cologne, Germany, 4Huffington Center on Aging, Dept. of Molecular and Cellular 

Biology, Baylor College of Medicine, Houston, (TX), USA, 5Dept. of Internal 

Medicine and Cell and Developmental Biology, UMich Medical School, Ann Arbor, 

(MI), USA 

Small-molecule ligands of nuclear hormone receptors (NHRs) play a central role in the 

regulation of metazoan development, cell differentiation and metabolism. While small changes 

in ligand structures strongly affects NHR transcriptional activity, the endogenous ligands of 

many metazoan NHRs still remain poorly characterized. 

Using comparative metabolomics, we identified the endogenous ligands of the C. elegans 

NHR DAF-12, a vitamin D and liver X receptor homolog that regulates larval development and 

adult lifespan. The identified molecules show strong bio-activity and include only one of two 

previously predicted DAF-12 ligands and feature unexpected structural motifs reminiscent of 

mammalian bile acids. 

Comparative metabolomics of mutants of steroid-modifying enzymes provides evidence 

for differential regulation of DAF-12-ligand biosyntheses, indicating that different endogenous 

NHR ligands may serve partially divergent functions. Our results show that previous, classical 

genetics-based hypotheses about NHR signaling in C. elegans must be revised and demonstrate 

the utility of unbiased comparative metabolomics for the identification of metazoan NHR ligands. 

Contact: parag.mahanti@gmail.com 

Lab: Schroeder 

38 

Session 5

Contact: haynesc@mskcc.org 

Lab: Haynes 


Direct Detection of Mitochondrial Dysfunction by the Transcription 

Factor ATFS-1 

Cole Haynes 

Memorial Sloan-Kettering Cancer Center 

Mitochondrial dysfunction contributes to the ill-effects of aging, diseases including cancer 

and Parkinson’s, as well as bacterial infection. The mechanisms organisms employ to protect 

cells from mitochondrial dysfunction are poorly understood. Our previous studies indicated 

that perturbations to mitochondrial function up-regulated mitochondrial chaperone genes via 

a signaling pathway termed the mitochondrial unfolded protein response (UPRmt), however 

the mechanism by which mitochondrial stress is detected and the signal communicated to the 

nucleus has remained elusive. An RNAi screen identified components required for signaling the 

stress response including the transcription factor ATFS-1. Consistently, worms lacking ATFS- 

1 are much more susceptible to mitochondrial dysfunction than wild-type worms. Here, we 

demonstrate that ATFS-1 directly monitors mitochondrial function to coordinate the induction 

of the UPRmt. Once activated, ATFS-1 mediates a broad transcriptional response of over 350 

genes to ameliorate the cellular and organismal effects of mitochondrial dysfunction. Included, 

are the expected mitochondrial chaperone and protease genes as well as ROS-detoxification 

machinery located throughout the cell. Components required for mitochondrial fission as well 

as autophagy were also induced by ATFS-1. Perhaps most interesting, we did not observe any 

induction of the electron transport chain genes. However, ATFS-1 did induce components of the 

glycolysis pathway suggesting that ATFS-1 mediates a shift in metabolism during mitochondrial 

dysfunction. The role of ATFS-1 and the UPRmt during physiological scenarios such as aging 

and bacterial infection will be discussed. 

Session 5 

39


Dissecting opposing age-dependent contributions of JNK signaling to 

stress resistance 

Kwame Twumasi-Boateng2,1 , Kuang-Hui Lee1 , Ali Salehpour1 , Michael Shapira1 1 2 Dept. of Integrative Biology, UC Berkeley (CA) USA, Graduate Group in 

Microbiology 

Physiological responses to adverse environmental conditions attempt to protect the animal 

from the relevant threat and maintain homeostasis. However, stress responses can also 

be detrimental, and this is usually thought to be the by-product of prolonged or excessive 

activation. We have recently identified an example in which the contribution of a stress 

protective mechanism changed from beneficial to detrimental without any difference in its 

activation, solely determined by the age of the animal (Twumasi-Boateng (2012) Aging Cell, 

in press). The age-dependent reversal was identified in the contribution of the conserved C. 

elegans JNK homolog, KGB-1. From providing protection against heavy metals and protein 

folding stress during development it becomes detrimental during early adulthood, sensitizing 

animals to environmental stress and shortening their lifespan. One mediator of kgb-1’s agedependent 

contributions was found to be the conserved longevity-associated transcription 

factor DAF-16 – DAF-16’s intestinal function was enhanced by KGB-1 in developing larvae, 

but attenuated in adults. Genetic analyses in daf-16 mutants corroborated the hypothesis that 

kgb-1-dependent lifespan shortening was mediated by DAF-16 attenuation, but showed no 

involvement of daf-16 in other kgb-1-dependent phenotypes, most intriguingly in its beneficial 

contribution to larval protection from heavy metals. Seeking to identify additional mediators of 

kgb-1-dependent and age-dependent phenotypes, we used microarray analysis to compare 

gene expression patterns between kgb-1 mutants and wildtype animals. These analyses 

revealed a large group of genes induced following kgb-1 activation independently of daf-16, 

among them genes induced in an age-specific manner, and further helped recognizing the 

extra-intestinal involvement of an additional transcription factor, FOS-1 (a component of the AP-1 

stress transcription factor), in the increased heavy metal resistance following KGB-1 activation 

in developing worms. We are continuing in de-constructing the age-dependent contribution of 

kgb-1 to stress responses and lifespan, and in characterizing the involvement of downstream 

processes and mediators. Our results to date depict KGB-1 as a hub for age-dependent and 

tissue-specific interactions and suggest that age is an important context determining whether 

KGB-1 activation would be beneficial or detrimental. 

Contact: mshapira@berkeley.edu 

Lab: Shapira 

40 

Session 5

Contact: pathu@umich.edu 

Lab: Hu 


A Genetic Screen for Novel DAF-16/FoxO Regulators 

Patrick Hu, Kathleen Dumas, Albert Chen, Hung-Jen Shih, Chunfang Guo 

Life Sciences Institute, University of Michigan, Ann Arbor, MI, United States 

FoxO transcription factors promote longevity in invertebrates and may control aging in 

humans. Mouse models implicate FoxO transcription factors in the pathogenesis of cancer, 

Type 2 diabetes, cardiovascular disease, and osteoporosis. Thus, understanding how FoxO 

transcription factors are regulated is expected to illuminate fundamental biological processes 

that underlie aging and age-related diseases. 

In C. elegans, the DAF-2 insulin-like signaling pathway and the germline are the major 

regulators of DAF-16/FoxO activity. Both inhibit DAF-16/FoxO by promoting its cytoplasmic 

sequestration. However, nuclear translocation of DAF-16/FoxO is not sufficient for activation, 

indicating that other inputs that control nuclear DAF-16/FoxO activity exist. We recently 

discovered EAK-7, a conserved protein of unknown function that acts in parallel to the serine/ 

threonine kinase AKT-1 to inhibit nuclear DAF-16/FoxO activity. How EAK-7 regulates DAF- 

16/FoxO is not known. Since EAK-7 is associated with the plasma membrane, it likely acts 

indirectly to control nuclear DAF-16/FoxO activity. 

To identify novel DAF-16/FoxO regulators in an unbiased manner, we have performed a 

genetic screen for suppressors of the dauer arrest phenotype of an eak-7;akt-1 double mutant 

(seak mutants). Whole genome sequencing of sixteen independent seak mutants has identified 

eighteen genes, each of which harbors distinct nonsynonymous mutations in more than one 

mutant strain. None of these genes has previously been implicated in FoxO regulation or lifespan 

control. We have validated two of these genes, both of which are conserved in mammals, 

as bonafide seak genes. The identification and characterization of seak mutants promises to 

yield new insights into the molecular basis of aging while engendering the development of 

new strategies to combat aging and age-related diseases. 


41


Interplay of Foreign and Endogenous Lectins in Innate Immunity of 


Therese Wohlschlager 1 , Alex Butschi 2 , Katrin Stutz 2 , Iain Wilson 3 , Michael Hengartner 2 , 

Markus Aebi 1 , Markus Kunzler 1 

1 Institute of Microbiology, ETH Zurich, Switzerland, 2 Institute of Molecular Life 

Sciences, University of Zurich, Switzerland, 3 Department of Chemistry, University 

of Natural Resources and Life Sciences (BOKU), Vienna, Austria 

Lectins are proteins that are able to recognize specific carbohydrate epitopes. As all living 

cells display a characteristic carbohydrate coat on their surface, lectins play an important role 

in intercellular and interorganismic interactions. In the context of Caenorhabditis elegans innate 

immunity, it has been hypothesized that endogenous lectins in the intestinal lumen shield 

endogenous carbohydrate epitopes from recognition by carbohydrate-binding bacterial toxins 

in that they display the same specificity as the toxin (1). However, only few molecular targets 

of endogenous and foreign lectins in C. elegans have been identified and characterized to 

date (2). Furthermore, it is not clear why lectins with the same specificity are toxic in one case 

(foreign lectins) but not in the other (endogenous lectins). 

During the last few years, we have isolated and characterized a variety of soluble, 

intracellular lectins from reproductive structures of different fungi and demonstrated that many 

of these lectins display toxicity towards Caenorhabditis elegans (3). We hypothesize that these 

lectins are part of an innate defense system of fungi against fungivorous nematodes. For some 

of the nematotoxic fungal lectins, we identified the carbohydrate epitopes that are recognized 

in C. elegans and are essential for susceptibility of the nematode to the lectin (4-7). These 

epitopes are nematode-specific, part of protein- or lipid-bound glycans and mostly localized 

to the apical surface of the intestinal epithelium. We have recently identified candidate C. 

elegans glycoproteins carrying glycans that are apparently targeted by different nematotoxic 

fungal lectins and also by endogenous C. elegans lectins. We are currently in the process of 

purifying these proteins in sufficient amounts from C. elegans to analyze their glycans. The 

results may provide further insight into the toxicity mechanism of foreign lectins and a possible 

role of endogenous lectins in C. elegans innate immunity. 

(1) Ideo et al. 2009 J. Biol. Chem. 284:26493-501 

(2) Takeuchi et al. 2011 Biol. Pharm. Bull. 34:1139-42 

(3) Bleuler-Martinez et al. 2011 Mol. Ecol. 20:3056-70 

(4) Titz et al. 2009 J. Biol. Chem. 284:36223-33 

(5) Butschi et al. 2010 PLoS Pathogens 6:e1000717 

(6) Wohlschlager et al. 2011 J. Biol. Chem. 286:30337-43 

(7) Schubert et al. 2012 PLoS Pathogens, in press 

Contact: markus.kuenzler@micro.biol.ethz.ch 

Lab: Aebi 

42 

Session 5

Contact: sunc@morpheus.wustl.edu 

Lab: Crowder 


Cell-Specific Hypoxic Injury in C. elegans: Modeling the Ischemic 

Penumbra 

Chun-Ling Sun 1 , Euysoo Kim 1 , C. Michael Crowder 1,2 

1 Department of Anesthesiology, 2 Department of Developmental Biology, 

Washington University School of Medicine, St. Louis, Missouri 

Stroke is the leading cause of disability in the US and the fourth leading cause of death yet 

has no approved cytoprotective therapy. In stroke, neurons in the most severely hypoxic areas 

die immediately while those in surrounding less hypoxic areas (termed the ischemic penumbra) 

are injured but may recover or have delayed cell death. The penumbral cells are the therapeutic 

target in stroke, but a genetically tractable model of the penumbra is lacking. Towards that end, 

we expressed rars-1(+) in C. elegans with cell-type-specific promoters in the background of 

rars-1(gc47rf), a mutation that strongly protects C. elegans from organismal hypoxic death. 

Hypoxic incubation of strains with pharyngeal myocyte-specific rars-1(+) expression in gc47 

produced severe pharyngeal pathology and pumping defects without killing the animal after 

initial recovery. We observed hypoxic necrotic cell death in the pharynx and in other parts of the 

worm whereas none was observed in the gc47 background strain. Over the next four days, we 

observed an increasing Unc phenotype and delayed animal death. Likewise selective rescue 

of gc47 in GABA neurons with rars-1(+) produced initial pathology in GABA neurons and then 

a delayed severe Unc phenotype (distinct from that produced by GABAergic dysfunction) and 

delayed animal death. Thus, these strains model aspects of the ischemic penumbra, particularly 

delayed cell death and spread of injury from primarily injured cells to surrounding cells. We 

are now beginning to ask if previously identified hypoxic protective mutants/RNAis function to 

protect particular cell types and primarily versus secondarily injured cells. 

Session 5 

43


Movement of RNA Silencing Between C. elegans Cells 

Antony Jose, Hai Le, Snusha Ravikumar, Sindhuja Devanapally 

University of Maryland, College Park, MD, USA 

RNA silencing is triggered by double-stranded RNA (dsRNA) and transported between 

cells in C. elegans. The import of silencing RNA into cells requires a conserved tyrosine kinase 

that likely promotes endocytosis and a conserved dsRNA-selective transporter that allows 

entry into the cytoplasm. Genetic mosaic analyses suggest that exported RNA comprise of 

two classes of dsRNA: long dsRNA and Dicer-processed short-interfering RNA (siRNA). Both 

classes of dsRNA are likely made and exported through a general mechanism that operates 

in all cell types because distinct tissues such as the gut, muscles, and neurons can all export 

silencing RNA. But, how cells decide to export silencing RNA and the molecular machinery 

that controls such export are unknown. 

Silencing RNA can either be exported from any cell within a tissue or from a specific subset 

that is specialized for RNA export. To distinguish between these two possibilities, we examined 

the silencing of a multicopy transgene that expresses green fluorescent protein (GFP) in C. 

elegans gut cells in the absence of RNA transport between cells. Gut cells that make and export 

silencing RNA will silence GFP expression, but cells that require the import of silencing RNA 

will fail to do so. We found that a subset of cells (~45% on average) in all animals silenced GFP 

expression. This subset, however, differed from one animal to another such that all gut cells 

could silence GFP expression in at least one animal. These results suggest that cells that export 

RNA silencing are determined in a stochastic manner in each animal. To identify mutants that 

are defective in the transport of mobile RNA between cells, we performed a forward genetic 

screen using dsRNA expressed from neurons (exporters) to silence GFP expression in gut 

cells (importers). We isolated 54 silencing exported from neurons defective (send) mutants 

using this screen and are currently analyzing 19 of the most strongly defective send mutants. 

Thus, the export of silencing RNA derived from expressed dsRNA is widespread and cells 

that export such RNA differ between animals of the same genotype. Our genetic screen, 

focused on the transport of RNA silencing between distinct tissues, is likely to uncover the 

proteins that enable this general RNA export mechanism. 

Contact: amjose@umd.edu 

Lab: Jose 

44 

Session 5

Contact: abigail.cabunoc@oicr.on.ca 

Lab: Stein 


WormBase 2012: Website Redesign 

Abigail Cabunoc, Norie de la Cruz, Adrian Duong, Maher Kassim, Xiaoqi Shi, Todd 

Harris, Lincoln Stein 

Ontario Institute for Cancer Research, Toronto, Canada 

WormBase (www.wormbase.org) has served the ever growing needs of the nematode 

research community since 2000. Initially created as a resource for the C.elegans genome and 

its biology, WormBase now includes a wider variety of data from 15 related species. This growth 

in data is mirrored by increased website use. In response to the constantly growing data and 

user traffic, the WormBase web team has redesigned both the underlying architecture and 

user interface of the website. In this interactive presentation, we will review the new WormBase 

website, walk through basic and advanced tasks using the new interface, and examine several 

features which take advantage of the nematode research community. 

Session 5 

45


Dynamic Neuroendocrine Signaling in C. elegans Behavioral 

Responses to Pathogenic Bacteria 

Dennis Kim 

MIT, Cambridge, MA 

We have investigated host-microbe interactions in Caenorhabditis elegans, focusing on the 

molecular genetic analysis of immune and neural responses to microbes in this simple host 

organism. The TGF-ß signaling pathway functions in the neuroendocrine regulation of diverse 

physiological processes in C. elegans. I will present our recent studies of how bacteria induce 

changes in TGF-ß signaling that promote pathogen avoidance behavior. 

Contact: dhkim@mit.edu 

Lab: Kim 

46 


Contact: rtaylor@salk.edu 

Lab: Dillin 


The UPRER is a Cell Non-Autonomous Regulator of Stress Resistance 

and Longevity 

Rebecca Taylor, Andrew Dillin 

Howard Hughes Medical Institute, The Salk Institute for Biological Studies, La 

Jolla, CA 

The ability to ensure proteostasis is critical for maintaining proper cell function and 

organismal viability, but is mitigated by aging. We analyzed the role of the endoplasmic reticulum 

Unfolded Protein Response (UPR ER ) in aging of C. elegans, and found that the ability to activate 

the UPR ER was lost with age. This age-onset loss of ER proteostasis could be reversed via the 

expression of a constitutively active form of XBP-1, XBP-1s. Expression of XBP-1s specifically 

in the nervous system was sufficient to rescue stress resistance, increase longevity and was 

able to specifically activate the UPR ER in distal, non-neuronal cell types through a cell nonautonomous 

mechanism. Loss of UPR ER signaling components in the distal cells blocked cell 

non-autonomous signaling from the nervous system, thereby blocking increased longevity of 

the entire animal. Reduction of small clear vesicle (SCV) release blocked the non-autonomous 

signaling of the UPR ER , suggesting that the release of neurotransmitters is required for this 

inter-tissue signaling event. Our findings point towards a Secreted ER Stress Signal (SERSS) 

that promotes ER stress resistance and longevity. 

Session 6 

47


Interactions between 1-carbon cycle and lipid metabolism in C. 

elegans 

Amy Walker 1 , Rene Jacobs 2 , Jenny Watts 3 , Veerle Rottiers 4 , Anders NAar 4 

1 UMASS Medical School Worcester, MA USA, 2 University of Alberta, Edmonton, 

Canada, 3 University of Washington Pullman, 4 MGH Cancer Center, Boston MA 

USA 

Nutritional and metabolic pathways feed into diverse cellular processes. A growing body 

of evidence also suggests that some transcription factors are affected by metabolic cues to 

coordinate gene expression with nutrient availability. The SREBP family of transcription factors 

regulate genes for generating fatty acids and phospholipid in metazoans and cholesterol 

synthesis in vertebrates. These factors are inhibited by cholesterol in vertebrates, however the 

regulatory feedback mechanisms for lipogenic genes have been less clear. Using C. elegans 

and mammalian models, we have found that SBP-1 and mammalian SREBP-1 control the 

expression of genes in the 1-carbon cycle, which produces methyl groups necessary for 

protein and phospholipid methylation. In addition, lack of phospholipid methylation initiates a 

regulatory cascade that results in increased SBP-1/SREBP-1 activity. Up-regulation of SBP-1/ 

SREBP-1 activity when methylation capacity or phospholipid synthesis is diminished results 

in increased lipogenesis and may be relevant to the development of fatty liver in mammals. 

Finally, our discovery that SREBP transcription factors are linked to metabolic pathways 

controlling methylation opens additional avenues in understanding how gene regulation is 

linked to metabolic control. 

Contact: amy.walker@umassmed.edu 

Lab: Naar/Walker 

48 

Session 6

Contact: wmadaki@gmail.com 

Lab: Suzuki 


Novel approach in oxidative stress study by targeted ROS generation 

using a photosensitizer SuperNova in C. elegans 

Hiroshi Suzuki, Donald Fu, Ippei Kotera, Po-An SU 

University of Toronto, Toronto, Ontario, CANADA 

Oxidative stress has been implied innumerable diseases, including cancer, myocardial 

infarction, and neurodegenerative diseases such as Parkinson’s Disease (PD). Traditional 

approaches have mostly relied on indirect generation of reactive oxygen species(ROS) using 

chemical inhibitors of mitochondria respiratory chain to induce oxidative stress; however, 

chemicals may diffuse into unexamined cells and exert unintended side-effects. The lack of 

specificity has hampered direct evaluation of its role in pathology and diseases. 

We here established a novel approach to directly generate ROS by using the photosensitizer 

SuperNova: a genetically-encoded, red fluorescent protein that generates ROS upon light 

activation, in specific cells, cellular compartments,and specific timing. SuperNova is a newly 

developed monomeric version of KillerRed. 

SuperNova was expressed specifically in mechanosensory neurons and dopaminergic 

(DA). Upon light activation, we induced neurodegeneration, revealed by loss of neuronal 

morphology, and by depletion in function as examined by behaviour assays. The behavioural 

response mediated by the mechanosensory neurons was rapidly abolished before the 

morphological change was detectable, which is analogous to various diseases that develop 

symptoms years before the appearance of neurodegenerations. In context of PD, we crossed 

our SuperNovatransgenic worms into the mutants of PD-related genes and observed a 

sensitization of DA neuron degeneration in lrk-1background, which is in good agreement with 

the proposed protection by LRRK2/lrk-1. Furthermore, our controlled activation of SuperNova 

killed DA neurons(PDE) while the adjacent mechanosensory neurons (PVM) remained intact 

in the cross of the two Tg strains, demonstrating the powerful model to address the selective 

death of DA neurons in PD. Moreover, we targeted SuperNova to the mitochondria of body 

wall muscles, which lead to deformed mitochondria, but nocell ablation was observed. We 

hypothesized a protective mechanism preventing the progress of damage, and addressed 

the protection by using deletion mutantsand feeding RNAi; cell ablation was observed when 

Parkin/pdr-1 mutant was combined with RNAi of sod-2 (mitochondrial superoxide dismutase) 

or pink-1. Thus, the novel method we established to deliver oxidative stress in specific cells, 

specific organelle at specific timing and duration in live animals will be a valuable tool to study 

oxidative stress and other physiological/pathological status where ROS plays roles. 

Session 6 

49


Natural Products that Suppress Protein Aggregation and Slow Aging 

Silvestre Alavez1 , Pedro Rodriguez1 , Maithili C. Vantipalli1 , David J. S. Zucker1,2 , 

Ida M. Klang1,3 Milena Price, Karla Mark, and Gordon J. Lithgow1 1Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, 

California 94945, USA. 2Department of Natural Sciences and Mathematics, 

Dominican University of California, San Rafael, California, 94901, USA. 

3Karolinska Institute, Center for Biosciences at NOVUM, Department of 

Biosciences and Nutrition, Hälsovägen 7, S-141 83 Huddinge, Sweden. 

We have undertaken screen of synthetic and natural compounds to find agents for aging 

interventions. Since aging can be considered a causal factor in a number of age-related 

diseases. We hope such screen could yield useful therapeutics. We focused our search on 

compounds that maintain protein homeostasis. Collapse of protein homeostasis results in 

protein misfolding cascades and the accumulation of insoluble protein fibrils and aggregates, 

such as amyloids. A group of small molecules, traditionally used in histopathology to stain 

amyloid in tissues, bind protein fibrils and slow aggregation in vitro and in cell culture. We 

proposed that treating animals with such compounds would promote protein homeostasis in 

vivo and increase longevity. Here we show that exposure of adult Caenorhabditis elegans 

to the amyloid-binding dye Thioflavin T (ThT) resulted in a profoundly extended lifespan and 

slowed ageing. ThT also suppressed pathological features of mutant metastable proteins and 

human β-amyloid-associated toxicity. These beneficial effects of ThT depend on the protein 

homeostasis network. Other agents that extend lifespan also suppress protein homeostasis 

such as Lithium. We are testing for common mechanisms of action. This is reveling tissue 

non-autonomous signaling between neurons and muscle. 

Our results to date demonstrate that pharmacological maintenance of the protein 

homeostatic network by natural products has a profound impact on aging rates, prompting 

the development of novel therapeutic interventions against ageing and age-related diseases. 

Contact: glithgow@buckinstitute.org 

Lab: Lithgow 

50 



Expression-level Polymorphism for the Rec-8 Gene Underlies 

a Quantitative Trait Locus Governing Lifespan, Multiple Stress 

Resistances, and X-Chromosome Nondisjunction 

Srinivas Ayyadevara 1,3 , Cagdas Tazearslan 2 , Ramani Alla 1 , Robert Shmookler Reis 1,3 

1 University of Arkansas for Medical Sciences, Little Rock,AR,USA, 2 Albert Einstein 

College of Medicine,Bronx, NY, 3 Central Arkansas Veterans Health Care System, 

Little Rock,AR,USA 

We identified a quantitative trait locus (QTL) on chromosome 4, lsq4, that affects lifespan 

and resistance to oxidative and thermal stresses in Caenorhabditis elegans. We have now 

defined lsq4 allelic effects on transcript levels of genes lying within the QTL region, and also 

across the entire genome. Of the twenty-eight confirmed genes in the lsq4 interval, eleven 

showed 2-to 15-fold allele-specific differential expression by quantitative real-time PCR. Ten 

differentially expressed lsq4 genes were examined for RNA-interference effects on the QTL 

traits. One gene, rec-8, increased lifespan when disrupted in worms bearing the shorterlived 

allele, but its knockdown had no effect in the longer-lived isogenic strain. RNAi to rec-8 

also reverts all other traits of the shorter-lived allele, including greater sensitivity to paraquat 

and heat shock, and reduced male frequency. Thus, allele-determined differences in rec-8 

expression can explain all known effects of this QTL. The rec-8 polymorphism may provide 

an instructive example of balancing selection (wherein each of two alleles is favored under 

different circumstances), and/or antagonistic pleiotropy (in which early benefits to Darwinian 

fitness drive selection for an allele that is deleterious in post-reproductive life). 

Contact: ayyadevarasrinivas@uams.edu 

Lab: Shmookler Reis 

Poster Topic: Aging 

51


Effects of Dietary Restriction by Axenic Medium on Mitochondrial 

Function in Caenorhabditis elegans. 

Natascha Castelein 1 , Berhanu Kassa 2 , Bart Braeckman 1 

1 Ghent University, Ghent, Belgium, 2 University of Cologne, Cologne, Germany 

C. elegans lifespan can be drastically extended by using a semidefined axenic culturing 

medium instead of the standard E. coli food source. This culturing method probably imposes 

dietary restriction (axenic dietary restriction, ADR) and slows down the aging process. The 

molecular causes of aging are not well understood, but it is widely believed that oxidative stress 

plays an important role in this process. Oxidative stress is a side effect of aerobic metabolism 

and may lead to progressive oxidative damage to macromolecules and a concomitant functional 

decline. Since aerobic metabolism occurs in the mitochondria, these organelles are considered 

to play a central role in the aging process. 

We hypothesize that mitochondria of the long-lived axenically cultured worms show a 

completely different physiology and are much more efficient compared to fully fed controls. 

To assess mitochondrial function, we measured oxygen consumption of isolated 

mitochondria, using a Clark type electrode (O2k, Oroboros instruments). Preliminary data 

suggest that respiration of isolated ADR mitochondria is substantially lowered compared to 

fully fed controls, but they appear to be better coupled. Further investigation will shed more 

light on how mitochondria are affected by ADR conditions. First, multiple substrate and inhibitor 

titration protocols will be applied to gain an extended understanding on the functions of different 

mitochondrial pathways under ADR conditions. Simultaneously, membrane potential will be 

monitored using TPP + electrodes. 

Second, in vivo quantification of ROS levels with transgenic worms expressing ROS 

biosensors will provide a better indication of real-time physiological conditions under ADR. 

Apart from mitochondrial physiology, we studied the role of DR-related genes in lifespan 

extension of ADR worms. We found that lifespan extension by ADR is partially dependent on 

AAK-2 and CUP-4 but independent of SKN-1 and UCP-4. 

Contact: Natascha.castelein@ugent.be 

Lab: Braeckman 

52 

Poster Topic: Aging

Contact: atchen@umich.edu 

Lab: Hu 


SGK-1 Extends Lifespan by Activating DAF-16/FoxO 

Albert Chen1 , Chunfang Guo2 , Kathleen Dumas1 , Travis Williams2 , Sawako Yoshina3 , 

Shohei Mitani3 , Kaveh Ashrafi4 , Patrick Hu2 1Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 

USA, 2Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA, 3Dept. of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, 

Japan, 4Dept. of Physiology, UCSF School of Medicine, San Francisco, CA, USA 

The FoxO family of transcription factors is implicated in aging and age-related diseases in 

species as diverse as invertebrates and mammals. In C. elegans, loss-of-function mutations 

in the conserved insulin-like signaling pathway result in increased transcriptional activity of 

the C. elegans FoxO ortholog DAF-16, which is sufficient to extend adult lifespan severalfold. 

DAF-16 and FoxO possess three highly conserved sites that lie within consensus motifs for 

the conserved AGC family kinases Sgk and Akt (referred to as AGC sites). Mammalian cell 

culture data suggest that phosphorylation of any of these sites by Sgk and Akt inhibits FoxO by 

promoting its cytoplasmic sequestration. Consistent with this model, C. elegans AKT-1 and AKT- 

2 limit lifespan by inhibiting DAF-16/FoxO. However, recent experiments using both loss- and 

gain-of-function mutations suggest that SGK-1 increases lifespan in C. elegans by activating 

DAF-16/FoxO, counter to the prevailing paradigm where SGK-1 solely inhibits DAF-16/FoxO. 

These results suggest that our understanding of how FoxO is regulated by Sgk is incomplete. 

We hypothesize that the FoxO N-AGC site acts as a conserved switch: SGK-1 phosphorylation 

of the C-AGC site inhibits DAF-16/FoxO when the N-AGC site is phosphorylated, but activates 

DAF-16/FoxO when the N-AGC site is not phosphorylated. To this end, we are building MosSCI 

strains harboring single-copy DAF-16/FoxO transgenes encoding various combinations 

of phosphomimetic and phosphodefective AGC site mutations. Because the mechanisms 

controlling DAF-16/FoxO activity are highly conserved, insights into the role of SGK-1 in 

controlling C. elegans longevity may be relevant to common human diseases associated with 

aging such as cancer, Type 2 diabetes, cardiovascular disease, and osteoporosis. 


53


Proteomic Changes Elicited by Metformin Treatment 

Wouter De Haes 1 , Roel Van Assche 1 , Steven Haenen 1 , Bart Braeckman 2 , Liliane 

Schoofs 1 

1 KU Leuven, Leuven, Belgium, 2 UGent, Ghent, Belgium 

Aging is a complex process in which molecular and cellular damage gradually accumulates, 

which in turn leads to increased vulnerability and ultimately death. Research has shown that 

aging and longevity are regulated by a combination of several pathways, although the specifics 

are still poorly understood. Many of these signaling pathways are involved in nutrient detection 

and, as such, it isn’t surprising that dietary restriction (a reduction in food uptake without 

malnutrition) leads to an extension of healthy lifespan. Metformin, the most widely used antidiabetic 

for the treatment of type-2 diabetes, also has lifespan-extending effects. Research 

has shown that this increase of longevity in healthy metformin-treated subjects might be the 

result of metformin mimicking the effect of dietary restriction. 

In our study, we use C. elegans and gel-based differential proteomics in order to elucidate 

the molecular effectors involved in the life-extending effect of metformin. Studies have already 

shown that the positive effect of metformin on C. elegans lifespan is dependent on AMPactivated 

protein kinase (AAK-2) and the skinhead (SKN)-1 transcription factor. Our proteomic 

study showed a significant upregulation of several proteins involved in carbohydrate catabolism, 

which is consistent with the predicted function of AAK-2. We also found overlap with data 

from several studies of dietary restriction, including downregulation of proteins involved in 

reproduction and the group of transthyretin-like proteins. Furthermore, we identified several 

upregulated proteins with unknown functions, including a protein with predicted kinase activity 

and a transcription factor. In the future, we will determine their effect on longevity and compare 

our results with planned gel-based proteomic studies of dietary restriction. 

Contact: wouter.dehaes@bio.kuleuven.be 

Lab: Schoofs 

54 

Poster Topic: Aging

Contact: kjdumas@umich.edu 

Lab: Hu 


The p120RasGAP Family Member GAP-3 is a Novel Regulator of Dauer 

Arrest and Longevity 

Kathleen Dumas2 , Stephane Flibotte1 , Don Moerman1 , Patrick Hu2 1 2 University of British Columbia, Vancouver, BC, Canada, University of Michigan, 

Ann Arbor, MI, USA 

In C. elegans, both reducing insulin/insulin-like growth factor signaling (IIS) and ablating 

the germline extend life span by promoting the translocation of DAF-16/FoxO to the nucleus. 

Nuclear DAF-16/FoxO induces transcriptional programs that promote longevity. The IIS pathway 

in C. elegans consists of conserved PI3K and Akt components that antagonize DAF-16/FoxO 

by promoting its cytoplasmic sequestration. We have discovered the EAK pathway, a novel, 

conserved pathway that inhibits DAF-16/FoxO. The EAK pathway acts in parallel to PI3K/Akt 

signaling to inhibit nuclear DAF-16/FoxO activity without promoting its translocation to the 

cytoplasm. How the EAK pathway inhibits DAF-16/FoxO is not known. 

To illuminate the mechanism underlying EAK pathway inhibition of nuclear DAF-16/FoxO 

activity, we identified suppressors of eak-7;akt-1 dauer arrest (seak mutants). We identified 

gap-3, a p120 GTPase activating protein (GAP) family member, as a seak gene. GAP-3 is 

homologous to human RASA1, which was first identified as a RasGAP that antagonizes 

Ras by promoting its GTPase activity. GAP-3 is one of three putative RasGAPs encoded in 

the C. elegans genome. A spontaneous missense mutation in the RasGAP domain of gap- 

3 suppresses the 25°C dauer arrest phenotype of eak-7;akt-1 double mutant animals. Two 

independent loss of function alleles of gap-3, zh94 and ga139, also suppress eak-7;akt-1 

dauer arrest, confirming gap-3 as a seak gene. In contrast, mutations in gap-1 and gap-2 did 

not significantly influence eak-7;akt-1 dauer arrest. Initial experiments suggest gap-3 mutation 

also suppresses the life span extension phenotype of eak-7;akt-1 double mutants. Notably, 

the let-60/Ras gain-of-function allele n1046 suppresses eak-7;akt-1 dauer arrest to a lesser 

degree than gap-3 loss-of-function alleles, suggesting that GAP-3 may have Ras-independent 

functions in the control of dauer arrest. These results implicate GAP-3 as a novel regulator 

of dauer arrest and longevity. We are currently exploring the potential role of GAP-3 in the 

transduction of signals from both the EAK pathway and the PI3K/Akt pathway to DAF-16/FoxO. 


55


Investigating the tissue-specific requirements for autophagy in C. 

elegans longevity mutants 

Sara Gelino, Malene Hansen 

Sanford-Burnham Institute for Medical Research, La Jolla, (CA), USA 

Multiple conserved pathways and processes can modulate lifespan, including dietary 

restriction and reduced insulin/IGF-1 signaling. We and others have recently shown that 

autophagy – a cellular process by which cytoplasmic components are degraded and recycled 

– is induced in multiple long-lived C. elegans mutants, including dietary-restricted eat-2 animals 

and in daf-2 mutants with reduced insulin/IGF-1 signaling. Accordingly, autophagy genes are 

required for the long lifespan of these mutants, suggesting that autophagy promotes longevity 

by mechanisms still to be identified. 

To learn more about the role of autophagy in aging, we are investigating where autophagy 

may promote longevity in the organism. To address this question, we are utilizing several 

tissue-restricted RNA interference models to inactivate autophagy in specific tissues of eat- 

2 and daf-2 mutants. Knowledge of where in the animal that autophagy appears to have a 

rejuvenating effect will shed light on the underlying mechanism by which autophagy may 

promote longevity. Interestingly, in our preliminary studies, we have observed that the longevity 

function of autophagy is indeed restricted to specific tissues of these long-lived animals. 

Based on these results, we propose that autophagy is utilized in certain tissues to remove 

damaged proteins and organelles that would normally accumulate during the aging process. 

In this way, the autophagic turnover of damaged macromolecules, the nature of which is still 

to be identified, may prolong the youthfulness of a cell, tissue, and organism. 

Contact: sgelino@sbmri.org 

Lab: Hansen 

56 

Poster Topic: Aging


Tumor suppressors and longevity in C.elegans 

Hakam Gharbi 1,2 , Francesca Fabretti 2 , Puneet Bharill 2 , Bernhard Schermer 1,2 , Thomas 

Benzing 1,2 , Roman Ulrich Mueller 1,2 

1 Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated 

Diseases, University of Cologne, Cologne, Germany, 2 Department II of Internal 

Medicine and Center for Molecular Medicine, University of Cologne, Cologne, 

Germany 

Caenorhabditis elegans is one of the most prominent model organisms in aging research 

due to its simple genetic amenability and short life-cycle. Recently several groups showed 

that loss of the tumor suppressor protein vhl-1 leads to longevity in the nematode. This effect 

is predominantly mediated by hif-1, a hypoxia-inducible factor, the degradation of which is 

mediated by vhl-1. This increased lifespan appears to be the consequence of an enhanced 

cellular stress response, since these strains do also show improved survival upon exposure 

to a row of stressors. 

In Von-Hippel-Lindau syndrome, which is a rare genetic condition that goes along with the 

development of various tumors, pVHL (Von-Hippel-Lindau protein) is mutated. Furthermore, 

pVHL was shown to be the most important renal tumor suppressor preventing the formation 

of Renal Cell Carcinoma. 

Work by both our and other groups now provides evidence that other tumor suppressor 

proteins are linked to longevity and regulation of cellular stress resistance in C.elegans. This 

finding indicates that protection from tumor formation in mammalian cells– which obviously does 

not play a role in a short-lived nematode – comes at the expense of reduced cellular fitness 

and stress resistance. The current data allow for the hypothesis that temporary inhibition of 

certain tumor suppressor proteins in a timely fashion that does affect tumorigenesis could be 

a novel tool to protect organs from damaging stimuli. 

Contact: hakam.gharbi@uk-koeln.de 

Lab: Benzing 


57


Identification of a Novel Bacterial Species That Extends the Lifespan 

of Caenorhabditis elegans 

Junhyeok Go 1,2 , Kang-Mu Lee 1 , Sang Sun Yoon 1,2 

1 Department of Microbiology, Yonsei University College of Medicine, Seoul, South 

Korea, 2 Brain Korea 21 Project for Medical Sciences, Yonsei University College of 

Medicine, Seoul, South Korea 

Caenorhabditis elegans is a nematode used in various fields of biological research. C. 

elegans has been a useful model organism to study innate immunity, because (i) its lifecycle 

is shorter than other higher order animals, (ii) it is genetically tractable, and (iii) it shares 

common innate immune systems with human. C. elegans has an alimentary canal, similar 

to the mammalian intestine. Therefore it has a potential to be used as a model organism to 

study microbial interaction with host intestine. At the moment, however, no bacterial species 

that forms commensal mutualism with C. elegans has been reported. Because C. elegans is 

originally isolated from soil, we tested several bacterial species of soil origin to examine whether 

they can formulate mutually beneficial relationship with C. elegans host. Many of tested strains 

exert no virulence to C. elegans. Importantly, one of them (soil isolate no. 2) let C. elegans 

live significantly longer than the common prey of C. elegans, Escherichia coli OP50 does. The 

median lethal time (LT 50) of this soil isolate no. 2 (SI-2) is over 140 % of the OP50 control. We 

are undertaking species identification of SI-2 at the moment. Not only extending C. elegans’ 

lifespan, SI-2 enhances larval growth of C. elegans. The size of larvae fed with SI-2 is twice 

the size of larvae fed with OP50 when compared at the early developmental stage, while the 

grown worms are of similar size. But SI-2 cannot rescue reduced resistance to pathogen after 

bacterial treatment at the pre-hatch stage. The pre-hatch bacterial treatment with all bacteria 

that we treated induces higher susceptibility to pathogens. Our results provide clues that may 

broaden our understandings of C. elegans lifecycle. 

Contact: megasage@hotmail.com 

Lab: Yoon 

58 

Poster Topic: Aging


The Role of Thioredoxin-1 (TRX-1) in Caenorhabditis elegans Aging 

Maria Gonzalez-Barrios 1,2 , Juan Carlos Fierro-Gonzalez 3 , Manuel Munoz 1 , Peter 

Swoboda 3 , Antonio Miranda-Vizuete 1,2 

1 Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville, 

Spain, 2 Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen 

del Rocio/CSIC, Seville, Spain, 3 Center for Biosciences at NOVUM, Dept. of 

Biosciences and Nutrition, Karolinska Institute, Huddinge, Sweden 

Thioredoxins comprise a conserved family of proteins that mostly depend on their 

oxidoreductase attributes to reduce disulfide bonds in many target proteins. These redox 

regulators are involved in many biological processes, including stress resistance and aging. 

In C. elegans, thioredoxin-1 (TRX-1) is expressed specifically in ASJ sensory neurons, which 

have been shown to regulate both dauer formation and longevity. Indeed, we have previously 

reported that trx-1 (ok1449) null mutants show a decrease in their lifespan while worms 

overexpressing trx-1 have a slight increase in lifespan. Aiming to determine the pathways 

where trx-1 impacts longevity, we generated double mutants of trx-1 (ok1449) with eat-2 

(ad1116), a genetic surrogate of caloric restriction. Interestingly, trx-1 (ok1449) fully suppressed 

the extended longevity of eat-2 (ad1116) mutants. Insulin signaling is another major pathway 

regulating longevity in all organisms and in C. elegans it has been shown to act independently 

of caloric restriction. Surprisingly, trx-1 (ok1449) also reduces the longer lifespan of the insulin 

receptor mutant daf-2 (e1370) by approximately 70%. However, trx-1 (ok1449) mutants do 

not suppress the extended longevity of downstream insulin pathway mutants such as pdk-1 

(sa680) and, interestingly, double mutants of trx-1 (ok1449) with the FOXO transcription factor 

gene daf-16 (mu86) are even shorter lived than any of the single mutants. Furthermore, trx-1 

(ok1449) mutants do not suppress the nuclear translocation of DAF-16::GFP in daf-2 (m577) 

mutants. Together, these data suggest that TRX-1 regulates longevity through the insulin 

pathway, albeit independently of DAF-16. The DAF-12 transcription factor belongs to the 

nuclear steroid hormone receptor family and has recently been shown to regulate the longevity 

of some insulin pathway mutants. To determine whether TRX-1 modulates insulin pathway 

longevity via DAF-12, we used the reporter DAF-9::GFP, which is a direct transcriptional target 

of DAF-12 and is upregulated in a daf-2 (m577) mutant background. Our preliminary data 

indicate that trx-1 (ok1449) mutants significantly downregulate DAF-9::GFP levels in a daf-2 

(m577) background, suggesting that trx-1 might also act in the steroid hormone route. Current 

efforts in the lab are dedicated to further explore the role of trx-1 in longevity mediated by the 

steroid hormone pathway. 

Contact: mgonbar@upo.es 

Lab: Miranda-Vizuete 


59


Aging is a Determinant in Anoxia Stress Tolerance in Caenorhabditis 

elegans 

Jo Goy1,2 , Pamela Padilla1 1 2 University of North Texas, Denton, Texas, USA, Harding University, Searcy, 

Arkansas, USA 

The physiology of aging is a hot topic in biological research, driven in part by the increasing 

age of the human population. Oxygen deprivation is associated with health issues such as 

stroke, pulmonary dysfunction and heart disease that commonly affect the elderly. We previously 

showed that the one-day old adult hermaphrodite survives 24h of anoxia (>90% survivorship, 

20C) yet are sensitive to long-term anoxia (LTA, 72h, 20C); anoxia sensitivity is suppressed by 

mutations resulting in sterility and decreased ovulation rate. The majority of stress response 

studies have been conducted on one-day old adult hermaphrodites. We determined that 

aging has a positive effect on LTA survival with a significant increase in survivorship at day 

3 of adulthood and a peak in 5-day old adults. The increase in tolerance was suppressed by 

mating at adult day 2, reinforcing the idea that reproduction compromises anoxia tolerance. To 

further analyze how aging animals respond to anoxia additional strains including the wild-type 

Hawaiian isolate (CB4856), LTA tolerant (daf-2(e1370), glp-1(e2141), fog-2(q71)) and sensitive 

(aak-2(gt33), daf-16(mu86)) strains were examined. LTA tolerant strains maintained a high 

level of survivorship through day 5 of adulthood at which point a gradual age-related decline in 

survival was observed. Similar to wild-type, LTA sensitive strains showed an increase in anoxiasurvival 

rate at day 3 of adulthood although rates failed to reach that of age-matched wild-type 

and LTA tolerant strains. These observations suggest the suppressive effect of reproduction 

is distinct from the genetic effect. Males show an age-related decrease in anoxia-tolerance 

distinct from hermaphrodites. To determine if age influences the effect of genotype on anoxia 

tolerance we analyzed survivorship of the double mutant glp-1(e2141); daf-12(rh61rh411) at 

day 1, 3, and 5 of adulthood exposed to LTA. At 1 day of adulthood absence of DAF-12 did not 

suppress survivorship after LTA exposure compared to age-matched LTA tolerant glp-1(e2141) 

controls. However, at day 5 of adulthood anoxia-survival was significantly decreased (p


LEP-2/Makorin Promotes let-7 microRNA-mediated Terminal 

Differentiation in Male Tail Tip Morphogenesis 

R Antonio Herrera, Karin Kiontke, David Fitch 

New York University, New York, (NY), US 

We have identified a new heterochronic gene, lep-2, which is required for male tail tip 

morphogenesis (TTM) during L4. Heterochronic genes regulate when stage-specific events 

occur during larval development. They interact in a pathway to ultimately schedule terminal 

differentiation events at L4. In males, terminal differentiation of the tail tip occurs at L4 as 

the tail tip cells (hyp8-11) change from a pointed cone-like shape to a rounded dome-like 

shape by cell fusion, retraction, and migration. Heterochronic genes that specify L4 fates 

(lin-41 and let-7) schedule TTM to start at mid-L4. When lost, lin-41 causes TTM to occur 

earlier (in L3), resulting in adult tail tip phenotypes that are over-retracted. When let-7 activity 

is reduced, TTM is delayed, resulting in adults with pointed, “leptoderan” tail tips. Loss-offunction 

mutations in lep-2 similarly produce a leptoderan phenotype, with a concomitant 

delay in the expression of dmd-3, the master regulator of TTM. lep-2 animals exhibit other 

developmental-delay phenotypes: they fail to exit the larval molting cycle or produce an “adult” 

cuticle. Also, in males the Lep phenotype is suppressed after passage through the dauer larvae 

stage. Through epistasis analysis, we have determined that lep-2 resides in the heterochronic 

pathway downstream of lin-14 to promote let-7. In lep-2 mutants we observe elevated levels of 

heterochronic gene reporters that are downregulated prior to TTM (lin-28 & lin-41). Our data 

suggest that the function of lep-2 is to negatively regulate lin-28, the let-7 repressor, and have 

found that LIN-28 protein levels are elevated in lep-2 mutants. With comparative genomic 

hybridization on a lep-2 deletion mutant, we identified lep-2 as the sole C. elegans Makorin 

(Mkrn). Mkrns are ancient eukaryotic genes which have conserved motifs: a RING domain 

flanked by 4 C3H-zinc fingers. Although the functional role of Mkrns during development has 

not been well understood, a general pattern is their involvement in terminal differentiation 

events. Our demonstration that the C. elegans Mkrn is a heterochronic gene suggests that 

an anciently conserved Mkrn function in mammals and nematodes may be to promote let-7mediated 

differentiation by repressing LIN-28 during development. 

Contact: antonio.herrera@nyu.edu 

Lab: Fitch 

Poster Topic: Small RNAs 

61


Translational Effect of Hydrogen Sulfide on C. elegans 

Joseph Horsman, Dana Miller 

Deparetment of Biochemistry, University of Washington, Seattle, WA, USA 

Exposure to low concentrations of H 2S has been shown to increase lifespan in C. elegans 

by 70%. The conserved transcription factor hypoxia inducible factor-1 (HIF-1), in additional to 

its role in responding to low concentrations of oxygen (hypoxia), is key in the initial response 

to H 2S. Hypoxia induces dramatic translational effects and it has recently been shown that H 2S 

can effect translation in specific mammalian tissues. Our goal is to characterize the organismal 

affects of H 2S in C. elegans. We have shown that exposure to low levels of H 2S does not change 

global levels of translation in C. elegans. In contrast, we do observe a dramatic decrease in 

translation when animals are exposed to hypoxia, as expected. The translation repression 

effects of acute hypoxia are HIF-1 independent. Unexpectedly, we have found that HIF-1 is 

required to maintain translation in H 2S. When H 2S concentration is increased to toxic levels, 

translation decreases in a manner corresponding to the toxic dose. We show that decreases 

in translation at high concentrations of H 2S are not correlated with survival. Together, our 

data suggest that effects of H 2S on C. elegans, such as lifespan, are not caused by changes 

in translation. This work helps build a basis to continue our work in studying the molecular 

mechanism by which H 2S affects C. elegans. 

Contact: horsman@uw.edu 

Lab: Miller 

62 

Poster Topic: Aging


Roles of Specific daf-16/FoxO Isoforms in Dauer Regulation and 

Lifespan Control 

Chunfang Guo 1 , Travis Williams 1 , Kathleen Dumas 1 , Sawako Yoshina 2 , Shohei Mitani 2 , 

Patrick Hu 1 

1 University of Michigan, Ann Arbor, MI, USA, 2 Tokyo Women’s Medical University 

School of Medicine, Tokyo, Japan 

FoxO transcription factors promote longevity in invertebrates and influence the pathogenesis 

of mouse models of common human diseases associated with aging such as cancer, Type 2 

diabetes, cardiovascular disease, and osteoporosis. In C. elegans, the FoxO transcription factor 

DAF-16 promotes dauer arrest in the context of reduced insulin-like signaling during larval 

development and prolongs adult lifespan. Recent work has implicated two distinct DAF-16/FoxO 

isoforms that possess unique N-terminal amino acid sequences, DAF-16A and DAF-16D/F/H, 

in dauer regulation and lifespan control. Our experiments with RNAi constructs that target 

specific daf-16/FoxO isoforms are consistent with previous studies suggesting that DAF-16A is 

the major isoform regulating dauer arrest, whereas both DAF-16A and DAF-16D/F/H play roles 

in lifespan control. To further elucidate the biological functions of DAF-16A and DAF-16D/F/H, 

we have isolated deletion mutations that affect specific daf-16/FoxO isoforms. Quantitative 

reverse transcriptase PCR confirmed the isoform specificity of these mutations. Thus far our 

analysis reveals that daf-16a-specific mutations fully suppress the dauer-constitutive phenotype 

of akt-1(mg306) and daf-2(e1368) mutants but only weakly suppress the dauer-constitutive 

phenotype of daf-2(e1370) mutants. These results are commensurate with those obtained 

with daf-16a-specific RNAi constructs. daf-16a-specific mutations also partially suppress the 

longevity phenotype of daf-2(e1370) mutants, consistent with previous findings implicating both 

DAF-16A and DAF-16D/F/H in lifespan control. Interestingly, in animals lacking a germline, daf- 

16a-specific mutations suppressed lifespan extension to nearly the same extent as a daf-16/ 

FoxO null mutation. Thus, in contrast to insulin-like signaling, which controls lifespan through 

both DAF-16A and DAF-16D/F/H, the germline influences longevity primarily by regulating 

DAF-16A activity. Experiments with daf-16d/f/h-specific mutations are ongoing. 

Contact: pathu@umich.edu 

Lab: Hu 


63


Quantitative In Vivo Redox Sensors Uncover Oxidative Stress as an 

Early Event in Life 

Daniela Knoefler, Maike Thamsen, Martin Koniczek, Nicholas Niemuth, Ann-Kristin 

Diederich, Ursula Jakob 

University of Michigan, Ann Arbor, MI 

Obstacles in elucidating the role of oxidative stress in aging include difficulties in 1) tracking 

in vivo oxidants, in 2) identifying proteins which are affected, and in 3) correlating changes in 

oxidant levels with lifespan. We used quantitative redox proteomics to determine the onset 

and the cellular targets of oxidative stress during the lifespan of Caenorhabditis elegans. In 

parallel, we used genetically encoded sensor proteins to determine peroxide levels in live 

animals in real time. We discovered that C. elegans encounters significant levels of oxidants 

as early as during larval development. Oxidant levels drop rapidly as animals mature and 

reducing conditions prevail throughout the reproductive age, after which age-accompanied 

protein oxidation sets in. Long-lived daf-2 mutants transition faster to reducing conditions, 

whereas short-lived daf-16 mutants retain higher oxidant levels throughout their mature life. 

These results suggest that animals with improved capacity to recover from early oxidative 

stress have significant advantages later in life. 

Contact: knoefler@umich.edu 

Lab: Jakob 

64 

Poster Topic: Aging


Genes Acting Downstream of Sensory Neurons to Influence 

Longevity, Dauer Formation and Pathogen Responses in C. elegans 

Marta Gaglia 1 , Dae-Eun Jeong 2 , Eun-A Ryu 2 , Dongyeop Lee 2 , Seung-Jae Lee 2 

1 University of California, Berkeley, Berkeley, California, USA, 2 Pohang University 

of Science & Technology, Pohang, Gyeongbuk, South Korea 

Sensory neurons of C. elegans affect the decision between arrest in the dauer stage 

and reproductive growth during larval development, and they also modulate the lifespan of 

the animals in adulthood. However, the molecular mechanisms underlying these effects are 

incompletely understood. Here we report how different effector genes act downstream of 

sensory neurons to influence three physiological outputs – longevity, dauer formation and 

pathogen response. We identified transcripts whose levels are influenced by mutations in the 

intraflagellar transport protein daf-10, which cause defects in the morphology and function of 

many ciliated sensory neurons in C. elegans. Among the genes with altered expression in daf- 

10 mutant animals, we found transcriptional targets of the DAF-12/nuclear hormone receptor. 

We show that DAF-12/nuclear hormone receptor influences specifically the high-temperatureinduced 

dauer-formation phenotype of these animals, but does not affect their extended 

lifespan. Moreover, we identified a solute transporter gene that is induced by daf-10 mutations 

and is required for their effect on longevity. Unexpectedly, we found that pathogen-responsive 

genes were repressed in daf-10 mutant animals and that these sensory mutants exhibited 

altered susceptibility to and behavioral avoidance of bacterial pathogens, independently of 

DAF-12/NHR or the solute transporter. Thus, sensory input seems to influence a diverse set 

of transcriptional responses that modulate basic biological processes in C. elegans. 

Contact: seungjaelee1@gmail.com 

Lab: Lee 


65


Age-dependent Alteration of Major Large Intestinal Granules in 


Kenji Nishikori, Takahiro Tanji, Eisuke Kuroda, Yuki Ueda, Hirohisa Shiraishi, Ayako 

Ohashi-Kobayashi 

Iwate Medical University, Yahaba, Iwate, Japan 

Dietary restriction response in C. elegans is one of the important targets of aging research. 

Intestine is a major organ responsible for uptake, digestion, storage and distribution of nutrients. 

In C. elegans intestinal cells, there are several different types of granules, which seem to be 

related with certain functions of the organ, however their function and regulation in response 

to internal and external conditions have yet to be elucidated. Therefore, we focused on the 

age- and nutrition-dependent changes of the intestinal granules in order to find new indexes 

of aging. 

At the late larval and early adult stages, at least three types of intestinal granules have been 

identified: lysosomotropic dyes (acridine orange and LysoTracker)–positive acidic granules, 

oil red O-positive fat storage granules, and LMP-1-localized non-acidic granules [1,2,3]. We 

previously reported that ABC transporters, HAF-4 and HAF-9, colocalize with LMP-1, on the 

surface of a major subset of intestinal granules. Interestingly, in the deletion mutants for haf-4 

and haf-9, loss of the non-acidic granules, but not of other granules, was observed [4]. 

Here we report that even in the haf-4 and haf-9 mutant worms, some kinds of intestinal 

granules come to occupy most of the cytosolic volume at the postreproductive adult stage. 

We aimed to characterize those granules emerging at the later stage of adulthood by using 

fluorescent protein-tagged marker proteins. As a result, LMP-1, HAF-4, and HAF-9 were not 

localized any longer on the major intestinal granules in the aged wildtype N2 worms. In addition, 

we also revealed that the difference of major granules in larvae and adults in response to food 

deprivation. HAF-4 and HAF-9-positive larval intestinal granules selectively decrease by food 

deprivation, whereas HAF-4 and HAF-9-negative intestinal granules in aged worms still exist 

after food deprivation treatment. These results indicate that the age-associated alteration of 

major intestinal granules happens during adulthood. Further molecular characterization of 

these granules is on going. 

References 

1. Hermann GJ et al. Mol. Cell. Biol. 2005. 2. O’Rourke EJ et al. Cell Metab. 2009. 3. Kostich M. et al. J. Cell. 

Sci. 2000. 4. Kawai H. et al. Mol. Cell. Biol. 2009 

Contact: aohashi@iwate-med.ac.jp 

Lab: Ohashi-Kobayashi 

66 

Poster Topic: Aging


Electrolyzed-reduced water confers increased resistance to 

environmental stresses and longevity in C. elegans 

Seul-Ki Park, Soon-Young Lee, Sang-Kyu Park 

Soonchunhyang University, Asan, Rep. of Korea 

Free radical theory of aging suggests oxidative stress caused by reactive oxygen species 

plays a pivotal role in normal aging. To determine the effect of reduced water on stress response 

and aging, we used electrolyzed-reduced water. Electrolysis of water produces reduced water 

at the cathode and oxidized water at the anode. Previous studies show that electrolyzedreduced 

water could block the activity of reactive oxygen species produced as a byproduct of 

metabolism in cells and protect cellular DNA from oxidative damage caused by free radicals in 

human lymphocyte. Here, we tested the effect of electrolyzed-reduced water on resistance to 

various environmental stresses, such as oxidative stress, heat stress, and UV in the nematode 

Caenorhabditis elegans. Worms grown in NGM media prepared with electrolyzed-reduced 

water have increased resistance to oxidative stress, thermotolerance, and UV-resistance 

compared to worms grown in media made with distilled water. We also observed a significant 

lifespan-extending effect of electrolyzed-reduced water in Caenorhabditis elegans. In addition, 

the fertility, one of biomarkers of healthspan in Caenorhabditis elegans, was significantly 

increased by electrolyzed-reduced water. These data suggest that electrolyzed-reduced water 

can play as a powerful radical scavenger and, as a result of that, can extend both lifespan and 

healthspan of Caenorhabditis elegans. 

Contact: skpark@sch.ac.kr 

Lab: Park 


67


A daf-16b-specific Mutation Extends C. elegans Lifespan 

Andy Polzin 1 , Chunfang Guo 1 , Sawako Yoshina 2 , Shohei Mitani 2 , Patrick Hu 1 

1 University of Michigan, Ann Arbor, MI, USA, 2 Tokyo Women’s Medical University 

School of Medicine, Tokyo, Japan 

In C. elegans, the FoxO ortholog daf-16 promotes dauer arrest, stress resistance, and 

lifespan extension in the context of reduced insulin-like signaling. Recent evidence has 

suggested that individual DAF-16/FoxO isoforms may have distinct biological functions. 

Studies in which each isoform was transgenically expressed in a daf-16/FoxO null background 

implicated DAF-16A and DAF-16D/F/H as the major isoforms governing dauer arrest, stress 

resistance, and lifespan control. To further explore the function of specific DAF-16/FoxO 

isoforms, we generated animals harboring deletion mutants that selectively eliminate the 

expression of individual DAF-16/FoxO isoforms. Strikingly, we found that animals with the 

daf-16b(tm5031) mutation live approximately 20% longer and are more thermotolerant than 

wild-type animals. This finding suggests that, in contrast to DAF-16A and DAF-16D/F/H, which 

promote longevity, DAF-16B shortens lifespan. daf-16b(tm5031) does not further extend the 

lifespan of daf-2 mutants or glp-1 mutants that lack a germline, suggesting that DAF-16B 

may control lifespan by regulating the activity of other DAF-16/FoxO isoforms. Experiments 

to determine the site of action of DAF-16B in lifespan control are ongoing. 

Contact: polzinaj@umich.edu 

Lab: Hu 

68 

Poster Topic: Aging


Molecular Mechanisms of C. elegans Germline Stem Cell Aging 

Zhao Qin, E. Jane Albert Hubbard 

Developmental Genetics Program, Skirball Institute of Biomolecular Medicine, 

NYU School of Medicine, New York, NY, USA 

Failure to maintain stem cells with age is associated with conditions such as tissue 

degeneration and increased susceptibility to tissue damage in many organisms, including 

humans. Here we use the C. elegans germ line as a general model to study stem cell aging. 

The C. elegans germ line combines a well-established genetic model for aging studies with an 

accessible stem cell system, providing a unique opportunity to dissect the effects of aging on 

stem cells. Our results suggest a depletion mechanism that requires insulin/IGF-like signaling 

via DAF-16/FOXO. Further, we found that insulin signaling acts neither in the germ line nor the 

intestine. These results suggest a novel mechanism for insulin/IGF-like signaling in regulating 

age-associated physiological changes that is anatomically separable from its previously 

described roles in larval germline proliferation and lifespan regulation. 

Contact: Zhao.Qin@med.nyu.edu 

Lab: Hubbard 


69


Nutritional Deprivation in the Late Larval Stages of C. elegans Induces 

Developmental Diapause at Precise Checkpoints 

Adam Schindler, L Baugh, David Sherwood 

Duke University, Durham, NC USA 

C. elegans has served as a model system to study the effects of nutritional conditions 

on development. When food is abundant, animals grow through four larval stages, L1–L4, 

before reaching adulthood. In the absence of sufficient nutrients, animals arrest growth either 

in the L1 larval stage or in dauer, an alternative developmental pathway that is initiated late 

in the L1 stage. The effects of nutrient deprivation on progression through later larval stages 

has not been thoroughly explored, and is of interest because several tissues develop during 

these times, including those that form the egg-laying system. To examine the effects of nutrient 

deprivation on later larval development, we first grew animals to approximately the L2 molt 

before removal from food. Under these conditions, animals arrested growth in the early-L3 

larval stage, as determined by molting cycle reporters and by the pattern of cell divisions in the 

vulval, uterine, sex muscle, and germline cell lineages. When animals were instead removed 

from food shortly after the L2 molt, about half the population passed the L3 checkpoint and 

invariantly molted to L4, where they again arrested in the early part of the larval stage. In 

L4-arrested animals, all of the tissue lineages examined developed beyond their L3 arrest 

points, suggesting that a global developmental checkpoint had been passed. The extent of 

development upon passing the L3 checkpoint varied between tissues: vulval precursor cells 

completed all cell divisions and arrested at a precise developmental point, whereas uterine, 

sex muscle, and germ cell divisions arrested at earlier developmental times and in a variable 

manner. Our results demonstrate that global checkpoints regulate development through the 

L3 and L4 larval stages, and that tissue-specific responses determine the extent of growth 

upon passing the checkpoints. Our work expands the range of developmental checkpoints in 

C. elegans to include the later larval stages after the dauer decision. 

Contact: adam.schindler@duke.edu 

Lab: Sherwood 

70 

Poster Topic: Aging


Shared Targets of TGF-β and Insulin/IGF-1 Signaling Regulate 

Reproductive Aging through Mechanisms Distinct from Somatic 

Aging Regulation 

Shijing Luo, Cheng Shi, Jasmine Ashraf, Coleen Murphy 

Lewis-Sigler Institute for Integrative Genomics and Department of Molecular 

Biology, Princeton University, Princeton, NJ 08544, USA 

In humans, female reproductive capacity decline is one of the earliest aging phenotypes. 

We recently found that both TGF-β Sma/Mab and Insulin/IGF-1 signaling (IIS) regulate C. 

elegans reproductive span through maintenance of oocyte and germline quality with age. 

However, the molecular mechanisms downstream of IIS that regulate oocyte quality are 

unknown. Furthermore, it is not known whether the mechanisms that maintain oocyte quality 

and reproductive span are the same as those that maintain somatic tissues with age and 

extend the life span of IIS mutants. 

Here we have used transcriptional analysis to identify a set of gene targets regulated 

by the IIS receptor DAF-2 in oocytes. Many of the daf-2 oocyte targets are shared with the 

oocyte targets of the TGF-β Sma/Mab signaling mutant, sma-2, which also slows reproductive 

aging. Our data suggest that the IIS and TGF-β Sma/Mab pathways share important common 

mechanisms of oocyte quality maintenance. These mechanisms are also the processes that 

decline with age in mammalian oocytes. By contrast, transcriptional analyses suggest that daf- 

2’s somatic and oocyte maintenance targets are largely non-overlapping. Thus, IIS appears to 

regulate reproductive aging and somatic aging through largely different mechanisms. Our results 

indicate that mitotic and post-mitotic cells use distinct molecular strategies to combat aging. 

Contact: cshi@princeton.edu 

Lab: Murphy 


71


The Role of FAHD1 in the Aging of Caenorhabditis elegans 

Andrea Taferner 1 , Haymo Pircher 1 , Lucia Micutkova 1 , Nektarios Tavernarakis 2 , Pidder 

Jansen-Duerr 1 

1 Institute for Biomedical Aging Research, Innsbruck, Austria, 2 Institute of 

Molecular Biology and Biotechnology, Foundation for Research and Technology, 

Heraklion, Greece 

The 25 kDa protein FAHD1 (FAH domain containing protein 1) is the second member of the 

FAH superfamily that has been identified in the human genome but it has not been researched 

extensively so far. In a recent study, it was shown that FAHD1 exhibits acylpyruvase activity, 

demonstrated by the hydrolysis of acetylpyruvate and fumarylpyruvate in vitro. The enzyme 

was found expressed in all tested murine tissues, with highest expression in liver and kidney 

and was also found in several human cell lines, where it localized to mitochondria (Pircher et 

al., 2011). Using a proteomic screen for mitochondrial proteins that are differentially regulated 

in young and senescent human cells, FAHD1 has been identified as a target for age-related 

post-translational modifications. 

Concerning organismic aging, it has been shown that the depletion of the FAHD1 gene 

product by RNAi led to a significant reduction in the mean lifespan of Caenorhabditis elegans. 

To further examine the physiological function of the FAHD1 ortholog in the worm, a FAHD1 

knock-out mutant C. elegans strain was generated. This mutant worm shows – in addition to 

the lifespan reduction - abnormalities in its phenotype compared to wild-type worms, especially 

concerning fecundity and locomotion. It will be used in a variety of experiments, including 

epistasis experiments and metabolic studies. 

The findings suggest an important function for the FAHD1 ortholog in C. elegans. We hope 

that with our work we will be able to clarify the physiological function and regulation of FAHD1, 

as well as its involvement in the aging process of C. elegans. 

Contact: andrea.taferner@oeaw.ac.at 

Lab: Jansen-Duerr 

72 

Poster Topic: Aging


Physical Interaction of Half ABC Transporters HAF-4 and HAF-9, 

Which Are Required for the Biogenesis of the Intestinal Lysosomerelated 

Organelles in Caenorhabditis elegans 

Takahiro Tanji, Kenji Nishikori, Hirohisa Shiraishi, Masatomo Maeda, Ayako Ohashi- 

Kobayashi 

Iwate Medical University, Yahaba, Iwate, Japan 

C. elegans HAF-4 and HAF-9 are ABC transporters highly homologous to human lysosomal 

peptide transporter TAPL (TAP-like; ABCB9). From their high identity at the amino acid sequence 

level, they are predicted to be paralogues. They colocalize on the membrane of non-acidic but 

LAMP (lysosome-associated membrane protein) homolog LMP-1-positive lysosome-related 

organelles in intestinal cells, and are both required for the normal formation of the organelles 

(Kawai et al. (2009) Mol. Biol. Cell, 20, 2979-90). Although the organelles are prominent from 

the late larval to young adult stage, they rapidly collapse by food deprivation, or disappear as 

the worm ages even under fed conditions. HAF-4 and HAF-9 might actually participate in the 

dynamic changes of the organelles in response to age and trophic conditions. 

As HAF-4 and HAF-9 are half-type transporters, they should function as homodimers and/ 

or a heterodimer. Preceding genetic interaction analyses between haf-4 and haf-9 proposed 

two possible models; they function as a heterodimer, and/or they function differentially but 

cooperatively as homodimers (Tanji et al., 4th East Asia C. elegans Meeting). However, which 

mode of dimerization they employ is yet to be identified. 

Here, we show that HAF-4 and HAF-9 require each other for their stable expression. 

Western blot analysis revealed that the expression level of HAF-4 and HAF-9 decreased in 

both the haf-4 and haf-9 single mutants. Moreover, knock-down of either gene by means of 

RNA interference results in the decreasing fluorescence of both HAF-4::GFP and HAF-9::GFP 

in the transgenic worms. These results suggest that HAF-4 and HAF-9 are not stable in the 

absence of each other. Furthermore, we detected the physical interaction between HAF-4::GFP 

and HAF-9::mCherry in the transgenic worms by co-immunoprecipitation analyses. These 

results strongly suggest the heterodimer formation of HAF-4 and HAF-9. 

Contact: ttanji@iwate-med.ac.jp 

Lab: Ohashi-Kobayashi 


73


Neurite Sprouting and Synapse Deterioration in the Aging C. elegans 

Nervous System 

Marton Toth1 , Ilija Melentijevic1 , Leena Shah1 , Aatish Bhatia1 , Kevin Lu1 , Amish Talwar1 , 

Haaris Naji1 , Carolina Ibanez-Ventoso1 , Piya Ghose1 , Angelina Jevince2 , Laura 

Herndon2 , Gyan Bhanot1 , Christopher Rongo1 , David Hall2 , Jian Xue1 , Monica Driscoll1 1 2 Rutgers University, Piscataway, NJ, USA, Albert Einstein College of Medicine, 

New York, NY, USA 

C. elegans is a powerful model for analysis of the conserved mechanisms that modulate 

healthy aging. In the aging nematode nervous system, neuronal death and/or detectable loss 

of processes are not readily apparent, but because dendrite restructuring and loss of synaptic 

integrity are hypothesized to contribute to human brain decline and dysfunction, we combined 

fluorescence microscopy and electron microscopy (EM) to screen at high resolution for nervous 

system changes. We report two major components of morphological change in the aging C. 

elegans nervous system: 1) accumulation of novel outgrowths from specific neurons, and 2) 

physical decline in synaptic integrity. Novel outgrowth phenotypes, including branching from the 

main dendrite or new growth from somata, appear at a high frequency in some aging neurons, 

but not all. Mitochondria are often associated with age-associated branch sites. Lowered insulin 

signaling confers some maintenance of ALM and PLM neuron structural integrity into old age, 

and both DAF-16/FOXO and heat shock factor transcription factor HSF-1 exert neuroprotective 

functions. hsf-1 can act cell autonomously in this capacity. EM evaluation in synapse-rich 

regions reveals a striking decline in synaptic vesicle numbers and a dimunition of presynaptic 

density size. Interestingly, old animals that maintain locomotory prowess exhibit less synaptic 

decline than same-age decrepit animals, suggesting that synaptic integrity correlates with 

locomotory healthspan. Our data reveal similarities between the aging C. elegans nervous 

system and mammalian brain, suggesting conserved neuronal responses to age. Dissection 

of neuronal aging mechanisms in C. elegans may thus influence the development of brain 

healthspan-extending therapies. 

Contact: marton.l.toth@gmail.com 

Lab: Driscoll 

74 

Poster Topic: Aging


Identification of the Core Chaperone Network that Modulates 

Proteostasis in C. elegans 

Cindy Voisine, Kai Orton, Richard Morimoto 

Northwestern University, Evanston, (IL), USA 

Chaperone networks have central roles in proteostasis to prevent misfolding and the 

accumulation of protein aggregates that occur during aging and age-related neurodegenerative 

disease. While chaperones have been shown to suppress aggregation and toxicity of diverse 

proteins in multiple model systems, nearly all of these studies have taken candidate gene 

approaches, thus providing little understanding of the chaperone network. To address this, 

we have taken a functional domain-based, hierarchical clustering approach to identify 203 

chaperones belonging to sixteen families including individualized cytoplasmic and organellar 

folding factors that are expressed in the metazoan C. elegans. Using well-characterized 

folding sensors, including disease associated proteins and metastable proteins expressed in 

the body wall muscles, we asked whether a shared chaperone network exists that maintains 

functionality in vivo despite the proteotoxic stress. Reduced expression of only 16 chaperones 

by RNAi, corresponding to specific members of the Hsp90, Hsp70, Hsp60 (chaperonin), Hsp40, 

and TPR families, enhanced toxicity when Aβ or polyglutamine is expressed. Despite having 

distinct primary amino acid sequences and no structural commonalities other than forming 

aggregates suggests that these specific members function as a core chaperone network to 

maintain proteostasis. Knockdown of the core chaperone network also destabilized endogenous 

metastable proteins and accelerated the onset of sarcopenia in wild type animals. These findings 

implicate a small limited network of core chaperones that protects the proteome during aging 

and in age-related diseases. 

Contact: c-voisine@northwestern.edu 

Lab: Morimoto 


75


The Conserved MicroRNA-80 Modulates C. elegans Longevity through 

Dietary Restriction 

Mehul Vora, Mitalie Shah, Jian Xue, Monica Driscoll 

Rutgers, The State University of New Jersey, Piscataway (NJ), U.S.A 

Dietary or Caloric restriction (DR) is a conserved metabolic pathway that can prolong 

longevity and extend mid-life vigor (healthspan). In almost all model organisms, DR can delay 

onset of age-associated diseases. We conducted a screen to ascertain whether any of the 

available mir mutants are in constitutive DR, using a unique fluorimetric signature for the C. 

elegans DR state that our lab previously discovered. We exploited this biomarker to screen 

through miRNA deletion mutants to identify mir mutants that might persist in a constitutive 

DR-like state. 

We identified a single mir mutant, affecting the conserved mir-80 gene, which robustly 

exhibits the fluorimetric DR signature. mir-80 mutants [referred as mir-80(Δ)] also exhibit 

reduced fecundity and appear pale and thin. Like DR-animals, mir-80(Δ) is hypersensitive 

to the DR mimetic drug metformin, which is the drug response expected for animals that are 

already in DR (pushed over the edge into starvation). Interestingly, a transcriptional GFP 

reporter for mir-80 is responsive to food (upregulated in the presence of food and downregulated 

in absence of food) for three different DR regimens and a key molecular reporter 

of DR, the transcription factor skn-1, is activated by mir-80 deletion.Consistent with being in 

DR, mir-80(Δ) also exhibits several parameters of healthy aging, including extension of mean 

lifespan, reduced age pigment accumulation, and maintenance of youthful swimming and 

muscle physiology in old age compared to wild type animals. Gene expression analysis and 

a pilot screen of known DR-associated genes identified 5 conserved genes to be involved 

in the longevity phenotypes of mir-80(Δ). We also show genetically that mir-80(Δ) longevity 

effects are partially dependent on IIS pathway components. In sum, the mir-80(Δ) mutant is 

constitutively in DR even though it eats an ad lib diet—and it ages well as a consequence. 

To our knowledge, this work describes the first miRNA that modulates healthy aging by DR 

metabolic regulation. 

Contact: mehulmvora@gmail.com 

Lab: Driscoll 

76 

Poster Topic: Aging


Supplemental cellular protection by a carotenoid astaxanthin extends 

lifespan via ins/IGF-1 signaling in C. elegans 

Sumino Yanase 

Daito Bunka University School of Sports and Health Science, Department of 

Health Science, Higashi-matsuyama, Saitama, Japan 

Astaxanthin (AX), which is produced by some marine animals, is a type of carotenoid 

that has antioxidative properties. In this study, we initially examined the effects of AX on the 

aging of a model organism C. elegans that has the conserved intracellular pathways related 

to mammalian longevity. The continuous treatments with AX (0.1 to 1 mM) from both the 

prereproductive and young adult stages extended the mean lifespans by about 16-30% in the 

wild-type and long-lived mutant age-1 of C. elegans. In contrast, the AX-dependent lifespan 

extension was not observed even in a daf-16 null mutant. Especially, the expression of genes 

encoding superoxide dismutases and catalases increased in two weeks after hatching, and 

the DAF-16 protein was translocated to the nucleus in the AX-exposed wild-type. These results 

suggest that AX protects the cell organelle mitochondria and nucleus of the nematode, resulting 

in a lifespan extension via an Ins/IGF-1 signaling pathway during normal aging, at least in part. 

Contact: syanase@ic.daito.ac.jp 

Lab: Yanase 


77


The Role of Thioredoxin Reductase in Inorganic Selenium Metabolism 

in C. elegans 

Christopher Boehler, Roger Sunde 

University of Wisconsin, Madison, WI, USA 

The trace element selenium (Se) is an essential mineral with a narrow range of 

concentrations between adequacy and toxicity. Recent studies have associated higher intakes 

of Se with prevention of cancer and other diseases, but increased Se supplementation has 

also demonstrated adverse effects on human health. Therefore, further understanding of the 

metabolism underlying Se toxicity is needed. In this study, we used a C. elegans biological 

model to assess chronic inorganic Se toxicity, and to determine the essentiality of a proposed 

key enzyme in inorganic Se reduction and metabolism, thioredoxin reductase (trxr). Wild-type 

N2 Bristol (N2B) worms were grown in a defined, Se-deficient axenic liquid media (0.1 µM 

Se) for a period of 12 days with increasing Se concentrations ranging from 0 mM-5 mM using 

different inorganic Se forms (selenate, selenite, selenide). Knock-out strains for trxr-1 and 

trxr-2 genes were created and utilized in dose response curves to investigate the essentiality 

of thioredoxin reductase in handling excess Se. N2B C. elegans exposed to Se in the form of 

selenite or selenide displayed a similar, sigmoidal growth response to increasing concentrations 

of Se with reduced growth at 0.1 mM Se, a 50% growth reduction (LC50) at 0.2 mM and 0.23 

mM respectively, and lethality at 1 mM Se. In contrast, selenate resulted in 1/5th the toxicity 

seen for selenite and selenide and a LC50 of 0.95 mM Se in N2B worms, with lethality not 

observed until 3 mM Se. trxr-1-/- and trxr-2 -/- knock-out strains were outcrossed to N2 males, 

with genotypes confirmed by PCR and SDS-PAGE gels. A double knock-out (dko) was created 

through crossing the single mutants to further determine if trxr is essential in increasing Se 

concentrations. The absence of the trxr-1, trxr-2, or both genes (dko) displayed no obvious 

growth defects, or changes in sensitivity to increasing concentrations of any form of inorganic 

Se. Interestingly, while the LC50 concentration ranged from 0.16-0.23 mM for selenite and 

selenide in wild-type, single and dko strains, the LC50 for selenate was about 4 fold higher 

(0.85 mM) in wild-type and knock-out strains. Results indicating a decreased toxicity of selenate 

compared to selenite or selenide. The absence of the thioredoxin reductase does not change 

the susceptibility to Se toxicity suggesting additional alternate reductase(s) can reduce selenite 

and selenate in C. elegans. (Funded in part by UW WIS04909 and WIS01435) 

Contact: cboehler@wisc.edu 

Lab: Sunde 

78 

Poster Topic: Metabolism

Contact: cbrey@marywood.edu 

Lab: Hashmi 


Regulation of lipid storage and secretion: Genetics and Molecular 

Analysis 

Christopher Brey1 , Jun Zhang2 , Sanya Hashmi2 , Randy Gaugler3 , Sarwar Hashmi 2 

1 2 Marywood University, Scranton, PA, 18505, LFKI, NY Blood Center, Manhattan, 

NY 10065, 3Rutgers University, New Brunswick, NJ 08901 

To maintain lipid homeostasis, dietary lipids are absorbed from the small intestine and 

transported to various organs and tissues. The excess of ingested food is largely converted 

into intracellular TG deposits in lipid droplets that are most prominent in mammalian adipose 

tissues and to a lesser degree in heart, muscle and liver. The stored TG provides the primary 

source of energy during periods of food deficiency. However, the accumulation of high TG 

levels can cause hyperlipidemia, a serious medical condition with a disturbing epidemic 

forecast afflicting a growing number of the human population. In mammals there is a strict 

regulatory mechanism of lipid transport and distribution that helps maintain normal levels of TG 

in adipocytes. Some members of mammalian Krüppel-like factors, KLFs are the key players 

controlling adipogenesis. We have shown that aberrant activity of a Caenorhabditis elegans 

KLF-3 not only results in high TG accumulation in the intestine but also caused defects in 

fertility suggesting that excessive fat deposition and reproductive defects may be intimately 

linked. We also found reduced expression of C. elegans dsc-4 and/or vit genes, the homologs 

of mammalian MTP and apoB respectively that control mammalian lipoprotein assembly and 

transport. Similar to klf-3 (ok1975) mutation, mutation in both dsc-4 (qm182) and vit-5 (ok3239), 

results in elevated levels of fat accumulation in worm intestine. Our data suggests that Klf-3 

functions to limit fat storage and plays a role in its mobilization to other tissues. Hence, klf-3 is 

an essential regulator of lipid storage and transport, that mutation in klf-3 affects this regulatory 

function leading to fat accumulation. Our research aim is to define the mechanisms by which 

KLF-3 exerts its effects, and sets the groundwork for translation of these findings towards the 

goal of improved prevention and treatment of hyperlipidemia, and its related disorders. We are 

using three complementary, but interdependent, strings of research involving a) C. elegans; 

b) cellular and c) mouse models. 

Poster Topic: Metabolism 

79


Investigation of Satiety Quiescence Signaling Using Automated 

Locomotion Assay and Hidden Markov Model Analysis to Identify 

Worm Behavioral States 

Thomas Gallagher, Leon Avery, Young-Jai You 

Virginia Commonwealth University, Richmond, VA, USA 

Satiated animals stop eating, stop moving, and go to sleep[1]. We identified a behavior in 

worms that mimics this behavior, satiety quiescence[1]. We have developed an automated and 

quantitative system tracking worm locomotion to provide a detailed and integrated analysis of 

worm nutritional state and signaling. Tracking worm locomotion shows long periods of inactivity 

under conditions that enhance satiety quiescence. This inactivity is not seen in conditions 

known to disrupt satiety quiescence; if worms are not fasted, if they are refed on poor quality 

food, or if they have a mutation in satiety signaling pathways. This validates our automated 

system for measuring satiety quiescence. 

Our tracking data show that conditions that disrupt satiety quiescence increase locomotion. 

Moreover, restoring pkg-1 expression in a dozen head neurons under the tax-4 promoter 

decreases locomotion back to the level of wildtype. Because the impaired satiety quiescence 

in daf-7 worms is rescued by expression of daf-7 in ASI neurons (contained in the tax-4 set) 

[1], we attempted to rescue pkg-1 worms by expressing pkg-1(gf) in ASI neurons. This results 

in a decrease in locomotion similar to the tax-4 rescue. Genetic ablation of the ASI neurons 

causes an increase in locomotion, further showing that satiety signals are conveyed in ASI 

neurons. Additionally, we used calcium imaging to find that ASI is activated by food and nutrients, 

suggesting a role for ASI neurons in conveying nutrient availability. 

To identify behavioral states from locomotion we are developing a Hidden Markov Model 

(HMM) analysis. This allows us to view the behavioral state of a worm over time and address 

more complex questions such as the effect of genes, food quality, and nutritional state on percent 

time spent in each behavioral state, frequency of switching between states, and whether there 

is a cyclic pattern of behavior. 

1. You, Y.J., et al., Insulin, cGMP, and TGF-beta signals regulate food intake and quiescence in C. elegans: 

a model for satiety. Cell Metab, 2008. 7(3): p. 249-57. 

Contact: gallaghertl@mymail.vcu.edu 

Lab: You 

80 



Circadian rhythms in metabolism, stress tolerance and pathogenesis: 

lessons from Caenorhabditis elegans. 

Maria Goya 1 , Andres Romanowski 1 , Maria Migliori 1 , Sergio Simonetta 2 , Diego 

Golombek 1 

1 Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina, 2 Fundacion 

Instituto Leloir, Ciudad Autonoma de Buenos Aires, Argentina 

Circadian rhythms in physiological patterns are ubiquitously found in nature. They are driven 

by endogenous biological clocks and are synchronized to environmental cues. C. elegans 

is a model organism widely used in diverse areas of research but not well characterized in 

chronobiological studies. C. elegans might provide fundamental information about the basis 

of circadian rhythmicity in eukaryotes, due to its ease of use and manipulations, as well as of 

availability of genetic data and mutant strains. We have designed an automated system to track 

individual nematodes and demonstrated the existence of circadian activity rhythms in both LD 

(light:dark, 12h:12h) and DD (constant darkness) conditions; circadian periods were found to 

be of 24.2 ±0.44 h and 23.9 ±0.40 h respectively. These rhythms were affected by a mutation 

in lin-42, a homolog of the clock gene per. In addition, circadian periods were temperaturecompensated 

and could also be entrained by temperature cycles. 

C. elegans is a soil-dwelling nematode subjected to daily changes in environmental 

stressors; the ability to predict such variation might confer an adaptative advantage. We studied 

stress tolerance to abiotic and biotic stressors and found a rhythm in tolerance patterns for 

oxidative and osmotic stress, peaking at daytime and nightime, respectively. Expression of 

stress-related genes was determined by qRealTime-PCR: gpdh-1 and gpx showed a significant 

diurnal variation. When exposed to Pseudomonas fluorescens or Pseudomonas aeruginosa 

(two soil-occuring bacteria that kill C. elegans), we found lower tolerance during nightime. 

We have also studied circadian rhythms in metabolic variables, such as food consumption 

and defecation. Food consumption rate (determined by decreasing OD600 of E. coli OP50) 

was shown to be rhythmic and a peak was found in the evening. Defecation rhythms also 

showed to be governed in a circadian manner. These results show that control animals have 

a 24 h modulation of the ultradian defecation rhythm. Finally, we have detected aaNAT activity 

and melatonin in this nematode. aaNAT exhibited a diurnal variation peaking at ZT12, and 

melatonin could serve as a possible circadian output signal. 

In summary, our results show that the circadian system regulates changes in behavior, 

metabolism, abiotic stress tolerance and host-pathogen interactions. However, the presence 

and function of an endogenous clock capable of orchestrating such temporal changes deserves 

further investigation. 

Contact: eugeniagoya@gmail.com 

Lab: Golombek 


81


Ceramide signal mediates antipsychotic drug-induced developmental 

delay and lethality in C. elegans. 

Limin Hao, Bruce Cohen, Edgar Buttner 

Mailman Research Center, McLean Hospital 

Our aim is to help define the molecular pathways and mechanisms of action of antipsychotic 

drugs (APDs), using C. elegans as a genetic model. Exposure to APDs early in development 

causes dose-dependent developmental delay and lethality in C. elegans. A genome-wide RNAi 

screen for suppressors of clozapine-induced developmental delay and lethality was performed 

and revealed 42 candidate genes, including sms-1, which encodes a sphingomyelin synthase. 

Specifically, this enzyme converts ceramide and phosphatidylcholine to sphingomyelin and 

diacylglycerol. As these lipids are important in intracellular signaling, the findings may be 

relevant to the molecular pathways by which APDs produce their long-term effects. By analyzing 

other enzymes involved in sphingolipid metabolism, we identified ceramide as a key molecule 

that mediates APD drug effects. One sms-1 isoform is expressed in the C. elegans pharynx, and 

its transgene rescues the sms-1 mutant phenotype. We thus examined pharyngeal pumping 

and found that APD-induced inhibition of pharyngeal pumping requires sms-1, a finding that 

may explain the role of the gene in mediating APD-induced developmental delay. Total lipids 

extracted from wild-type worms are able to rescue APD-induced developmental delay and 

lethality. While limited to C. elegans, so far, similar mechanisms may be observed and can be 

studied in mammalian cells, to test their relevance to the clinical outcome of APD treatment. 

Contact: lhao@mclea.harvard.edu 

Lab: Buttner 

82 


Contact: nharriso@scripps.edu 

Lab: Gill 


Functional Characterization of C. elegans N-acylethanolamine 

Biosynthetic Enzymes 

Neale Harrison, Ifedayo Victor Ogungbe, Matthew Gill 

The Scripps Research Institute, Scripps Florida, 130 Scripps Way, Jupiter, Florida, 

33458 

N-acyl ethanolamines (NAEs) are an important class of lipid signaling molecules that 

includes the mammalian endocannabinoid arachidonoyl ethanolamide (also known as 

anandamide). We recently identified several NAEs in C. elegans and found that they are 

important for larval development and in adult animals they influence lifespan via nutrient sensing 

pathways. NAE metabolism is a tightly regulated process due to the ‘on demand’ nature of this 

signaling pathway. In mammals, this is achieved by balancing the activity of the biosynthetic 

enzyme N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) with the activity of 

the hydrolytic enzyme fatty acid amide hydrolase (FAAH). Our previous work focused on the 

effect of a specific NAE (eicosapentaenoyl ethanolamide, EPEA) and the role of FAAH in 

development and aging. We have now sought to characterize the role that the biosynthetic 

enzyme NAPE-PLD plays in NAE metabolism and life history traits in the worm. 

Based on sequence alignments, there are two NAPE-PLD homologs in C. elegans, 

nape-1 and nape-2, both of which retain the conserved-metallolactamase catalytic residues 

found in mammalian NAPE-PLD. We find that recombinant NAPE-1 and NAPE-2 are capable 

of liberating NAEs from N-acyl phosphatidylethanolamine substrates in vitro, providing 

biochemical evidence for a conservation of function. Although these enzymes contain strong 

sequence similarity, they are expressed in distinct, as well as overlapping, tissues suggesting 

the possibility of both divergent and redundant functions. Divergent functions are suggested 

by the ability of nape-1 overexpression, but not nape-2, to alter lifespan, while nape-2 overexpression, 

but not nape-1, leads to L1 arrest in a daf-2 mutant background. Individually, 

nape-1 and nape-2 over-expression have subtle effects on life history traits, but surprisingly 

when both are over-expressed simultaneously we observe L1 arrest. In order to understand 

the phenotypes conferred by the different genetic manipulations of these two genes, we are 

using gas chromatography - mass spectrometry to assess how nape-1 and nape-2 affect the 

levels of each of the different NAEs in vivo. 


83


The Mediator Subunit MED15/MDT-15 is a Conserved Transcriptional 

Co-regulator in Lipid Homeostasis 

Nicole Hou, Donha Park, Stefan Taubert 

University of British Columbia, Vancouver, Canada 

Regulation of metabolism is crucial for survival and development. Transcriptional regulation 

is one of the most important levels for metabolic control. The Mediator is a multi-subunit 

protein complex that regulates transcription by linking transcription factors to the general 

transcriptional machinery. MDT-15, the Caenorhabditis elegans homolog of the human 

Mediator subunit MED15, regulates genes involved in fatty acid metabolism and several 

stress responses. Specifically, MDT-15 is required for the production of polyunsaturated fatty 

acids, which are essential nutrients for C. elegans. Thus, worms with depleted or mutated 

mdt-15 display phenotypes such as developmental arrest, sterility, abnormal lipogenesis and 

shortened lifespan. However, defects in PUFA metabolism don’t fully explain the pleiotropic 

effects of mdt-15 depletion, prompting us to investigate additional metabolic pathways in 

these mutants. We found that MDT-15 is required to express genes involved in the uptake 

and metabolism of folate, a key precursor for the universal methyl-group-donor SAM. SAM 

is essential for various cellular reactions, including the synthesis of phospholipids (PLs), 

which play a key role in the construction of membranes. Therefore I hypothesize that MDT- 

15 is required for normal fatty acid metabolism, phospholipid biosynthesis and organelle 

structures. To determine whether MDT-15 affects folate, SAM, and PL levels, I am profiling 

both the expression of relevant genes and the lipid contents in the mdt-15-depleted worms. I 

found that several genes in the pathways responsible for phosphatidylcholine synthesis are 

significantly downregulated. Because lipid metabolism is closely linked to energy homeostasis 

as well as organelle structures and functions, I am also investigating the roles of MDT-15 in 

glucose metabolism and various subcellular organelles. I found that glucose level is reduced 

in worms with depleted or mutated mdt-15and ER stress is highly elevated in these worms. In 

addition, I will use an unbiased suppressor screen to identify and dissect new pathways that 

affect the metabolic pathways controlled by MDT-15. Lastly, I will test whether mammalian 

MED15 similarly regulates metabolism. Our studies will yield novel insights into a conserved 

regulator of metabolism that may be linked to human metabolic disorders. 

Contact: hjn31340@hotmail.com 

Lab: Taubert 

84 



L1 longevity is determined by metabolic rate and that AMPK as a 

master regulator of metabolism controls 

Inhwan Lee 1 , Amber Hendrix 1 , Jennifer Yoshimoto 2 , Jeongho Kim 3 , Young-Jai You 1 

1 Biochemistry and Molecular Biology, Virginia Commonwealth University, 

VA, USA, 2 Department of Internal Medicine, University of Michigan, MI, USA, 

3 Department of Biological Science, Inha University, Incheon, Korea 

Animals have to cope with starvation. The molecular mechanisms by which animals survive 

long-term starvation, however, are not clearly understood. When they hatch without food, C. 

elegans arrests development at the first larval stage (L1) and survives more than two weeks. 

Here we show that the survival span of arrested L1s, which we call L1 longevity, is a starvation 

response regulated by metabolic rate during starvation. A high rate of metabolism shortens 

the L1 survival span, whereas a low rate of metabolism lengthens it. The longer worms are 

starved, the slower they grow once they are fed, suggesting that L1 arrest has metabolic 

costs. Furthermore, mutants of genes that regulate metabolism show altered L1 longevity. 

Among them, we found that AMP-dependent protein kinase (AMPK), as a key energy sensor, 

regulates L1 longevity by regulating this metabolic arrest. Our results suggest that L1 longevity 

is determined by metabolic rate and that AMPK as a master regulator of metabolism controls 

this arrest so that the animals survive long-term starvation. 

Contact: ilee4@vcu.edu 

Lab: You 


85


Proteomic Study and Marker Protein Identification of Caenorhabditis 

elegans Lipid Droplets 

Pingsheng Liu, Peng Zhang, Huimin Na 

Institute of Biophysics, Chinese Academy of Sciences 

Lipid droplets (LDs) are a neutral lipid storage organelle that is conserved across almost 

all species. Many metabolic syndromes are directly linked to the over-storage of neutral lipids 

in LDs. The study of LDs in Caenorhabditis elegans (C. elegans) has been difficult since the 

lack of specific LD marker proteins. Here we report the purification and proteomic analysis of C. 

elegans LDs for the first time. We identified 306 proteins, 63% of these proteins were previously 

known to be LD-proteins, suggesting a similarity between mammalian and C. elegans LDs. 

Using morphological and biochemical analyses, we show that a short-chain dehydrogenase 

is almost exclusively localized on C. elegans LDs in both in vivo and in vitro experiments, 

indicating that it can be used as a LD marker protein in C. elegans. We also identified other 

two major proteins of LDs. These results will facilitate further mechanistic studies of LDs in 

this powerful genetic system, C. elegans. 

Contact: pliu@ibp.ac.cn 

Lab: Liu 

86 



WormSizer: High-Throughput Image Analysis of Nematode Size and 

Shape 

Brad Moore, James Jordan, Ryan Baugh 

Duke University, Durham, NC, USA 

The fundamental phenotypes of growth rate, size and morphology are the result of complex 

interactions between genotype and environment. We developed a high-throughput software 

application, WormSizer, that computes size and shape of nematodes from brightfield microscopy 

images. Existing methods for estimating volume either coarsely model the nematode as a 

cylinder, or assume the worm shape or opacity is invariant. Our estimate is more robust to 

changes in morphology as it only assumes that the worms are radially symmetric. We use 

a point distribution model (PDM) to characterize the shape and variation of different classes 

of nematodes. This open source software is written as a plugin for the well-known image 

processing framework Fiji/ImageJ, and it includes additional support for CellProfiler. It may 

therefore be extended easily. We used this framework to analyze growth and shape of several 

canonical C. elegans mutants in a developmental time series. Our analysis confirmed and 

extended on existing phenotypic characterization, demonstrating the utility and robustness of 

WormSizer. We show that a trained maximum likelihood classifier on the PDM can be used 

to discriminate strains, automatically identifying mutants that are phenotypically distinct from 

wild-type. We confirm quantitatively that a Dpy mutant is short and fat, that a Lon mutant is 

long and thin, and that a daf-2 insulin-like receptor mutant grows slow. We can also distinguish 

dauer larvae from normal larvae. WormSizer works with Unc and Rol mutants as well, showing 

wild-type morphology but delayed growth. We show for the first time that Sma mutants lay 

small eggs and that the larvae are actually smaller from the time of hatching onward. 

Contact: brad.t.moore@duke.edu 

Lab: Baugh 


87


Acetylcholine Dependent Starvation Signaling 

Robert Pollok, Leon Avery 

Virginia Commonwealth University, Richmond, VA, USA 

Starvation induced lethality in gpb-2 loss of function worms can be rescued by inhibiting 

acetylcholine signaling, suggesting cholinergic neurons propagate a starvation signal in C. 

elegans. GPB-2 is a regulator of G protein signaling, and the loss of function mutant has 

increased MAPK activation. You et al (Cell Metabolism 3: 237) showed that MAPK activation 

is increased in the presence of arecoline, an agonist to acetylcholine receptors, and decreased 

with atropine, an antagonist to acetylcholine receptors. When gpb-2(-) worms are treated with 

atropine, they are less sensitive to starvation induced lethality. Laser ablation of the cholinergic 

MC neurons also rescues starvation induced lethality in gpb-2(-) worms. Utilizing recombinant 

caspases to genetically ablate MC, I hope to further describe acetylcholine dependent starvation 

signaling in C. elegans. 

Contact: rhpollok@gmail.com 

Lab: Avery 

88 



How to sense fasting : searching for the mechanism of energy 

homeostasis by IRE-1 

Jisun Shin 1 , Hyungmin Moon 2 , Jiwon Shim 2 , Junho Lee 1,2 

1 World Class University Program, Department of Biophysics and Chemical 

Biology, Seoul National University, Seoul, Korea, 2 Department of Biological 

Sciences, Institute of Molecular Biology and Genetics, Seoul National University, 

Seoul, Korea 

Most organisms store fat as an energy source and use it during fasting. In our previous 

study we demonstrated that fasting induced lipases fil-1 and fil-2 were up-regulated in the 

IRE-1/HSP-4- dependent and xbp-1-independent manner upon fasting. In this study, we are 

trying to establish how IRE-1 sensors the fasting condition of the animal. To address the 

question, we chose lipid-derived signaling molecules, nucleic acids, and energy sources 

from food as candidate signaling molecules of fasting. After treating these molecules without 

other nutrients, we are analyzing the changes in the fil-1 and fil-2 levels. We are also trying 

to elucidate the mechanism of IRE-1 activation upon fasting. The fact that the induction of 

fil-1 and fil-2 was independent of xbp-1 indicates that the protein domains of IRE-1 may act 

differently upon fasting from those in the condition of conventional unfolded protein response 

(UPR). Therefore, we try to determine the roles of the domains within IRE-1 during fasting. 

Through these experiments, we hope to contribute to further understanding of the mechanism 

of energy homeostasis through IRE-1. 

Contact: jasminbinu@naver.com 

Lab: Lee 


89


Pigment dispersing factor - a neuropeptidergic influence on 

metabolism and stress 

Liesbet Temmerman, Ellen Meelkop, Tom Janssen, Liliane Schoofs 

KU Leuven, Leuven, Belgium 

On top of classical neurotransmitters, C. elegans uses neuropeptides as messengers 

or modulators in the nervous system, which mainly act upon G protein-coupled receptors 

(GPCRs). Most of the 1300 predicted GPCRs in C. elegans are uncharacterized orphans, i.e. 

their ligands and function(s) are unknown. 

Our group identified a GPCR signaling system resembling both the invertebrate PDF 

system as well as the widely studied vertebrate VIP signaling system. In insects, PDF function 

is profoundly studied with regard to molecular dissection of the circadian clock. The drawback 

of this focus is a remaining ignorance on possible other functions for PDF, which are better 

described for the vertebrate homolog VIP. Using the molecular toolkit available for C. elegans, 

we have broadened the scientific view on invertebrate PDF signaling systems and observed 

additional resemblances to the vertebrate VIP system. 

A combination of differential transcriptomic and proteomic data strongly indicates a 

modulatory role for the PDF signaling system in energy metabolism, especially under starvation. 

This aspect of PDF signaling finds its counterpart in the vertebrate VIP system, which also is 

involved in fatty acid metabolism and seems to be needed under starvation. Functions of the 

PDF signaling system in resistance to stress are also apparent from these molecular data, in 

addition, pdf mutant worms seem to cope better with osmotic stress than wild type worms do. 

Our data support the hypothesis that the PDF system in C. elegans modulates a broad 

range of processes, rather than being confined to the regulation of circadian rhythms. 

Contact: liesbet.temmerman@bio.kuleuven.be 

Lab: Temmerman 

90 



Ethanol Influence on Gonadal Development in C. elegans daf-18/PTEN 

Mutants 

Tim Wolf 1 , Wenjing Qi 1 , Ralf Baumeister 1,2 

1 Bioinformatics and Molecular Genetics (Faculty of Biology), Albert-Ludwigs- 

University Freiburg, 79104 Freiburg, Germany, 2 Freiburg Institute for Advanced 

Studies,School of Life Sciences (FRIAS LIFENET),BIOSS Centre for Biological 

Signaling Studies, Freiburg, Germany 

During its development, C. elegans encounters different larval stages in which, depending 

on nutritional status, stress or pheromones, decisions have to be made to either proceed 

and become adult, or to arrest and go to dormancy. The genes encoding the components 

of the insulin/IIs pathway are controlling the most crucial developmental decisions during 

the L2 larval stage. Active insulin/IGF signaling results in developmental progression into 

becoming a reproducing adult, whereas reduced signaling provokes the entry into an 

alternative developmental stage, the dauer larva. Mutations in daf-18, the homolog of the tumor 

suppressor gene PTEN (phosphatase and tensin homolog mutated on chromosome 10) result 

in defective dauer entry and also defective L1 arrest after starvation. The abnormal L1 arrest 

is accompanied by a disordered cell cycle arrest in germline progenitor cells Z2 and Z3 at G2 

phase. Thus, focusing on the germline we discovered that daf-18(lf) animals recovering from 

a three days nutritional deprivation period display a phenotype composed of a disintegrated 

gonadal basement membrane and inordinate distribution of germline cells throughout the 

somatic tissue. During our studies evidence could be provided, that ethanol supplementation 

whilst starvation decreased the penetrance of this phenotype, not only in daf-18 single mutants, 

but also in distinct mutants showing a less severe phenotype. Moreover, as Ethanol was 

supplemented at very low concentration and N2 larvae under this treatment remained in L1 

diapause, it could be assumed that ethanol does not simply act as food compensation. We 

are investigating whether ethanol acts as a carbon source or if there is an ethanol sensitizing 

pathway regarding our phenotype. 

Contact: tim.wolf@biologie.uni-freiburg.de 

Lab: Baumeister 


91


Increased Levels of Hydrogen Peroxide Induce a HIF-1-dependent 

Remodeling of Lipid Metabolism in C. elegans 

Meng Xie, Richard Roy 

McGill University, Montreal, (Quebec), Canada 

Cells have evolved numerous mechanisms to circumvent stresses caused by the 

environment, many of which are regulated by the AMP-activated kinase (AMPK). Unlike most 

organisms, C. elegans AMPK null mutants are viable, but die prematurely in the “long-lived” 

dauer stage due to rapid exhaustion of triglyceride energy stores. Using a genome-wide RNAi 

approach we demonstrate that the disruption of genes that increase hydrogen peroxide levels 

enhance the survival of AMPK mutants by altering both the abundance, and the nature, of the 

fatty acid content in the animal by increasing the HIF-1-dependent expression of several key 

rate-liming enzymes involved in de novo fatty acid biosynthesis. Our data provide a mechanistic 

foundation to explain how an optimal level of an often vilified ROS-generating compound such 

as hydrogen peroxide can provide cellular benefit; a phenomenon described as hormesis, by 

instructing cells to readjust their lipid biosynthetic capacity through downstream HIF-1 activation, 

as a means to correct cellular energy deficiencies. 

Contact: meng.xie@mail.mcgill.ca 

Lab: Roy 

92 



The Transmembrane Channel-like Protein TMC-1 Affects Adaptation to 

a Chemically Defined Medium in C. elegans 

Liusuo Zhang, L Rene Garcia 

Howard Hughes Medical Institute, Department of Biology, Texas A&M University, 

College Station, TX USA 

Animals must change their cellular metabolism and behavioral responses in order to invade 

and thrive in alternative nutritional environments. A chemically defined axenic medium, C. 

elegans maintenance medium (CeMM), has been established for culturing of C. elegans, which 

is a manipulable nutritional platform to dissect cell physiology. Worms grown on CeMM plates 

develop slower and exhibit a prolonged reproductive period with a decreased brood size. For 

N2 animals, about 10 percent of them develop into adults at day 8 after hatching, whereas the 

others reach adulthood in the following 10 days. Compared to the lab-bred wide type N2 strain, 

CB4856, a wild Hawaiian strain, takes greater than 16 days to reach adulthood. By screening 

known mutations which may affect feeding and growth, we observed that hermaphrodites 

containing mutations in fat-3, lev-11, ser-7, tph-1 and unc-73 developed faster than wild type 

in CeMM (30-80 percent reached adulthood between 5 and 7 days), while daf-2, daf-19, che- 

2, mdt-15, osm-9, unc-26, unc-32 and unc-42 mutants grew much slower or developmentally 

arrested in L1 (the majority could not develop into adults by two weeks). Through screening 

of EMS generated N2 mutant hermaphrodites that grow even faster in CeMM, we identified 

the rg1003 allele, which cause 90 percent of the worms develop into adults on the synthetic 

medium by day 5. Using two-point mapping, Illumina next generation sequencing, Sanger resequencing 

and complementation test, we mapped the rg1003 mutation to the gene tmc-1, 

which encodes a putative transmembrane channel-like protein, expressed on muscles and 

motor neurons. Other life history traits such as brood size, reproductive aging and life span, 

which were not directly selected for were not affected by tmc-1(rg1003). Animals must be able 

to sexually reproduce in order to thrive in new environments, therefore we examined the male 

mating potency of tmc-1(rg1003). We found that mutant males had higher mating potency than 

wild type on CeMM, whereas they were similar to wild type when grown on OP50 bacteria. 

qPCR analysis revealed that some genes associated with NADH production(fat-6, gpd-2 and 

gpd-3) were increased in tmc-1(rg1003) compared to N2 when synchronized starved worms 

were transferred to CeMM liquids for 2 hours, which suggests TMC-1 may facilitate energy 

homeostasis and metabolism regulation. 

Contact: lzhang@mail.bio.tamu.edu 

Lab: Garcia 


93


Screening for novel regulators of rnt-1 in stress response 

Soungyub Ahn 1 , Junho Lee 1,2 

1 Research Center for Functional Cellulomics, Institute of Molecular Biology and 

Genetics, School of Biological Sciences, Seoul National University, Korea, 2 World 

Class University, Department of Biophysics and Chemical Biology, Seoul National 

University, Seoul, Korea 

RUNX family transcription factors have various essential roles in mammalian development 

and carcinogenesis. Alternative splicing, post-transcriptional regulation and interaction with other 

nuclear components offer various levels of regulation and essential functions of RUNX proteins. 

In Caenorhabditis elegans, rnt-1 is the sole homolog of the RUNX family, and expressed in the 

intestine and hypodermal seam cells. In addition, RNT-1 represses its own transcription with 

BRO-1 but DBL-1 acts to activate rnt-1 expression at the post-embryonic stages. We focused 

on a novel rnt-1 regulation mechanism in C. elegans. We previously identified that the stability 

of RNT-1 in the intestine is regulated by various stresses. The p38 MAPK pathway, which is 

important to stress response, mediates the increase of RNT-1 stability in the intestine. Now, 

we are trying to find novel regulators which involved in this rnt-1 regulation by using antibiotics 

selection and focusing on change of GFP localization. 

Contact: syahn87@snu.ac.kr 

Lab: Lee 

94 

Poster Topic: Stress


Screening Nuclear Receptors to Discover the Regulation of the 

Xenobiotic Stress Response 

Leah Blackwell, Amanda Marra, Andrew Davidson, Tim Lindblom 

Lyon College 

Worms enjoy a robust detoxification system that allows them to cope with a diverse array 

of chemical stressors in their environment. This system is complete with members of all the 

major detoxification enzyme classes in animals. We are studying the mechanisms that allow 

intestinal cells to upregulate the expression of specific detoxification enzymes in response 

to specific xenobiotics. Much of our work has centered around the nuclear receptor, NHR-8, 

which is required for wild type levels of toxin resistance. To probe the role of NHR-8 in the 

xenobiotic stress response, we have analyzed the expression of genes in animals that lack 

NHR-8 and are challenged with xenobiotics. Our data indicates that NHR-8 does not mediate 

the up-regulation of detoxification genes but is likely required for basal expression of many 

intestinally expressed genes. What proteins might mediate the xenobiotic stress response and 

do they cooperate with NHR-8 for their activity? To answer this question, we have initiated a 

feeding RNAi screen of the transcription factor loci expressed in the gut to find those that are 

required for toxin resistance. This screen also probes the RNAi targets in combination with 

the loss of NHR-8 to look for cooperative control. Of particular interest are the 120+ nuclear 

receptors with demonstrated expression in intestinal cells. These proteins are ideally suited to 

mediate chemically induced gene expression through their ligand and DNA-binding domains. 

This type of nuclear receptor action would help explain why C. elegans contains comparatively 

many more nuclear receptors than other animals. 

Contact: leah.blackwell@lyon.edu 

Lab: Lindblom 

Poster Topic: Stress 

95


Depletion of the Nascent Polypeptide-associated Complex in C. 

elegans Up-regulates ER Chaperone Expression and Engages the 

Unfolded Protein Response, Resulting in the Induction of Autophagy 

and Apoptosis 

Paul Arsenovic, Anthony Maldonado, Vaughn Colleluori, Tim Bloss 

James Madison University, Harrisonburg, VA, USA 

The nascent polypeptide-associated complex (NAC) is a highly conserved heterodimeric 

complex important for metazoan development, but its molecular function has not been fully 

defined. Recent evidence in S. cerevisiae supports the hypothesis that the NAC is a component 

of the cytosolic chaperone network that interacts with both ribosomal complexes and their 

emerging nascent peptides, such that the loss of the NAC in chaperone-depleted cells results 

in an increase in misfolded protein stress. We tested whether the NAC functions similarly in C. 

elegans and found that its homologous NAC subunits, i.e. ICD-1 and -2, have chaperone-like 

characteristics; loss of the NAC appears to induce misfolded protein stress in the ER, triggering 

the unfolded protein response (UPR). Depletion of either subunit altered the worm’s response 

to heat stress, and led to a dramatic up-regulation of HSP-4, the homologue of the human 

chaperone and ER stress sensor BiP. Worms lacking both ICD-1 and the UPR transcription 

factor XBP-1 generated a higher proportion of defective embryos and had a diminished survival 

rate relative to ICD-1-depleted animals with an intact UPR. Up-regulation of HSP-4 was celltype 

specific; in embryos lacking ICD-1 or -2, the gut cell region showed strong up-regulation 

of HSP-4 and resistance to cell death relative to the neuronal region, which showed little to no 

increase in HSP-4 expression and significant cell death. Furthermore, loss of ICD-1 generated 

the presence of lipofuscins in both embryonic and mature gut cells, indicating an induction of 

ER-mediated autophagy. These results cast C. elegans NAC as an essential component of 

protein folding and localization during translation, and confirm C. elegans as a valuable model 

for studying organismal and cell-type specific responses to misfolded protein stress in the ER. 

Contact: blossta@jmu.edu 

Lab: Bloss 

96 



Genetic analysis of the Unfolded Protein Response during pathogen 

infection in C. elegans 

Douglas Cattie, Kirthi Reddy, Claire Richardson, Dennis Kim 

Department of Biology, Massachusetts Institute of Technology, Cambridge, MA. 

The Unfolded Protein Response (UPR) is a homeostatic mechanism that functions to oppose 

the accumulation of unfolded protein in the endoplasmic reticulum (ER) by carefully regulating 

several aspects of cellular physiology. In metazoans, there are three branches of the UPR— 

IRE-1/XBP-1, PERK/PEK-1, and ATF-6—each of which senses the concentration of unfolded 

protein in the ER lumen with a transmembrane protein and then transduces this signal to other 

cellular compartments. Prior work in our lab has shown that one of these branches, IRE-1/ 

XBP-1, is critical for the development and survival of C. elegans on the pathogen Pseudomonas 

aeruginosa 1 . We therefore conducted a screen to identify suppressor mutations that enable 

xbp-1 mutant animals to develop to adulthood on P. aeruginosa. Classes of suppressor mutants 

that have been isolated exhibit differential responses to pathogen-induced and abiotic sources 

of ER stress, as well as distinct genetic interactions with pathways mediating the UPR. The 

identification of these mutants is ongoing and the progress will be presented. 

1. Richardson et al. Nature 463, 1092 (2010). 

Contact: dcattie@mit.edu 

Lab: Kim 


97


BCAS2 is Essential for Drosophila Viability and Functions in PremRNA 

Splicing 

Po-Han Chen 1 , Yeou-Ping Tsao 2 , Show-Li Chen 1 

1 National Taiwan University, Taipei, Taiwan, 2 MaKay Memorial Hospital 

BCAS2 (Breast carcinoma amplified sequence 2, also known as SPF27) was previously 

reported as a negative regulator of p53. Here, we demonstrate that BCAS2 is essential for 

the viability of Drosophila melanogaster in which CG4980 (dBCAS2) is an ortholog of human 

BCAS2 (hBCAS2). We find that whole-body silencing of dBCAS2 leads to larval lethality, and 

that knockdown of dBCAS2 using a tissue specific promoter results in deformed phenotypes. 

The deprivation of dBCAS2 in Drosophila results in the accumulation of pre-mRNA and the 

induction of the dp53-targeted reaper and hid genes. Most importantly, overexpression of 

hBCAS2 can rescue lethality and wing deformities, indicating that hBCAS2 plays a similar 

role to dBCAS2. Furthermore, as a component of hPrp19 complex, we characterize the role of 

hBCAS2 in mammalian cells in both constitutive and alternative splicing. The C-terminal domain 

of hBCAS2 contains two coiled-coil motifs that directly binds to CDC5L and recruits hPrp19/ 

PLRG1 to form a core complex for pre-mRNA splicing. We also find that ectopic expression 

of the C-terminal region of human BCAS2 partially restores wing damage induced by silenced 

dBCAS2 in flies. In summary, Drosophila and human BCAS2 share at least two functions: one 

for p53 regulation and the other for RNA splicing, which affect cell growth viability. 

Contact: showlic@ntu.edu.tw 

Lab: Chen 

98 



Oxidative stress related PMK-1-HIF-1 signaling pathways in silver 

nanoparticles toxicity in C.elegans 

Jinhee Choi, Hyun - Jeong Eom, Jeong-Min Ahn 

University of Seoul, Seoul, Korea 

Silver nanoparticles (AgNPs) have been increasingly used in both consumer and biomedical 

applications, due to their antimicrobial and anti-inflammatory. Despite of recent numerous 

research on the toxicity and safety of AgNPs, serious deficiencies in the knowledge relating 

to AgNPs toxicity still exist, especially on its mechanism. Reactive oxygen species (ROS) 

generation and oxidative stress are the best developed paradigms to explain toxic effects of 

AgNPs. In the present study, a toxicity mechanism of AgNPs was investigated in Caenorhabditis 

elegans focusing on oxidative stress response. Initially, AgNPs were tested as potential 

oxidative stress inducers, and increased formation of ROS was observed in AgNP-exposed 

C. elegans. Subsequently, the potential upstream signaling pathway activated in response 

to AgNP exposure was investigated, paying special attention to the C. elegans PMK-1 P38 

mitogen-activated protein kinase (MAPK). The results indicated that AgNPs exposure led to 

increased ROS formation, increased expression of PMK-1 P38 MAPK and hypoxia-inducible 

factor (HIF-1), glutathione S-transferase (GST) enzyme activity, and decreased reproductive 

potential in wildtype C. elegans; whereas in the AgNP-exposed pmk-1 mutant, ROS formation 

and HIF-1 and GST activation were not observed, and decreased reproductive potential was 

rescued, suggesting the importance of PMK-1 P38 MAPK in oxidative stress response by 

AgNPs. In the second part, we investigated physiological consequences of HIF-1 activation 

by examining the response of regulators of HIF-1, such as, EGL-9 and VHL-1, and that of 

genes known to be regulated by HIF-1, such as, FMO-2. To test whether AgNPs-induced HIF-1 

activation is due to hypoxic response via ROS, pharmacological rescue assay was conducted 

using a strong antioxidant, N-Acetyl-Cysteine (NAC), on the HIF-1 and related pathways and 

the results suggest oxidative stress is involved in activation of HIF-1 pathway. Overall results 

suggest that oxidative stress is an important mechanism of AgNP-induced toxicity in C. elegans 

and that PMK-1 p38 MAPK and HIF-1 play important roles in it. The results also suggest that 

GST, FMO-2 and HIF-1 activation by AgNP exposure are PMK-1 p38 MAPK–dependent, and 

that they play important roles in the PMK-1 p38 MAPK-mediated stress response to AgNP 

exposure in C. eleganss. 

Contact: jinhchoi@uos.ac.kr 

Lab: Choi 


99


Insulin-like signaling in the parasitic nematode Brugia malayi 

Kirsten Crossgrove, Brenda Garland, Peter Sackett 

UW-Whitewater, Whitewater (WI), USA 

Brugia malayi is a mosquito borne parasitic nematode that is a causative agent of lymphatic 

filariasis in humans. Transmission from the mosquito to human host triggers molting from the 

L3 (infective stage) to the L4 stage. We are interested in the signaling pathways that trigger 

this developmental transition in the new host. The free-living nematode Caenorhabditis elegans 

also responds to environmental cues during development. Crowding, low food and/or high 

temperature all contribute to sending C. elegans into an alternate third larval ‘dauer’ stage. If 

conditions improve, the worms recover from dauer and molt to fourth stage larvae. The dauer 

larva is thought to be analogous to the infective stage larva in B. malayi. In both species, an 

environmental cue is required to trigger the molt to the L4 stage. An insulin/insulin-like signaling 

(IIS) pathway is one of the known regulators of dauer formation and recovery in C. elegans. 

Specifically, an active DAF-2 insulin receptor signals for reproductive development (no dauer 

formation) and recovery from dauer. One target of the IIS pathway is the DAF-16 protein, a 

FOXO transcription factor. Insulin signaling results in modification of DAF-16 to keep it in the 

cytoplasm. In the absence of insulin signaling, DAF-16 can enter the nucleus and regulate 

target genes. We have identified putative orthologs in B. malayi of a number of IIS pathway 

genes. We used qRT-PCR to determine if these genes are expressed in a developmentally 

regulated manner in B. malayi. The eight genes we have analyzed to date showed different 

expression levels at different life cycle stages, suggesting that they may play a role in a IIS 

pathway in B. malayi. We are currently conducting functional characterization of the Bm-daf-16 

gene. We have expressed the DNA binding domain in E. coli and will present data on binding 

to DAF-16 response elements. Genes in the IIS pathway could be useful targets for drugs or 

vaccines that prevent molting of B. malayi infective stage larvae. 

Contact: crossgrk@uww.edu 

Lab: Crossgrove 

100 



Using Mathematical Models to Predict Gene Flow and Discover Gene 

Function 

Andrew Davidson, Marc-Andre LeBlanc, Megan Powell, Tim Lindblom 

Lyon College 

Much of the work in our laboratory for several years has been to discover the functions 

of genes whose phenotypes might not be readily apparent in the plush environment of the 

laboratory. For example, we have probed the role of NHR-8 in the regulation of the detoxification 

response. Knockout alleles of nhr-8 have no phenotype under typical laboratory growth 

conditions. Similarly, many strains produced by the Gene Knockout Consortium or animals in 

RNAi screens do not display obvious phenotypes. We propose that worms in the environment 

are subject to significantly more stressors and that many of these genes encode proteins that 

protect worms during stress. The xenobiotic stress response is an excellent example. Until 

we challenge worms lacking full length NHR-8 with toxins, they appear no different from wild 

type worms and even then, the phenotype is weak. In order to design a more sensitive assay 

for gene necessity, we are developing mathematical models for predicting allele frequency in 

a population starting with a single heterozygote. After many generations, one would expect 

the typical 1:2:1 ratio of mutant and wild type alleles if there has been no selection against 

the mutant allele. By adding stressors to this population, we hope to statistically demonstrate 

selection by a reduction in the mutant allele frequency in the final gene pool. Using a panel of 

stressors, we might begin to tag genes without obvious phenotypes to biological functions for 

more detailed analysis. Our pilot experiments are with nhr-8 alleles and xenobiotic challenges. 

At the meeting, we will report on our progress towards implementing the mathematical models 

and expansion of the assay. 

Contact: andrew.davidson@lyon.edu 

Lab: Lindblom 


101


EGL-9 Function is Required to Produce Viable Offspring from Animals 

Exposed to Chronic Hypoxia 

Jennifer Dennis, Pamela Padilla, Brent Little 

University of North Texas, Denton, TX, USA 

Conserved molecular mechanisms, such as the HIF-1/EGL-9 signaling pathway, have 

evolved in metazoans to respond to and survive oxygen deprivation making C. elegans a good 

model system to understand the mechanisms regulating responses to hypoxia. The majority of 

studies thus far have involved acute exposures to hypoxia at specific developmental stages. 

In this study we investigate how C. elegans respond to chronic hypoxia exposure. We found 

that wild-type animals exposed to chronic hypoxia (.5% O 2 or 1% O 2) throughout development 

(embryo to gravid adulthood) survive. However, animals displayed various phenotypes including 

a decrease in developmental trajectory, a reduction in brood size, an increase in mean lifespan 

and an altered egg-laying behavior indicating that C. elegans can survive prolonged stress 

but at a cost to brood size. For wild-type animals, the embryos (F1 generation) from animals 

exposed to chronic hypoxia throughout development are viable. However, the F1 generation 

of egl-9 mutants exposed to chronic hypoxia were not viable indicating that egl-9 function is 

required for chronic hypoxia exposure. EGL-9 is known to regulate HIF-1 levels in that HIF-1 

accumulates in egl-9 mutants exposed to normoxia making it somewhat counterintuitive that 

the egl-9 mutants are sensitive to chronic hypoxia. Possible interpretations of these results 

will be presented. Further, we are conducting genetic and cellular analysis to elucidate the 

role EGL-9 has in chronic hypoxia exposure. 

Contact: jennifercdennis@gmail.com 

Lab: Padilla 

102 



Analysis a Null Allele of the Heterochronic Gene lin-42, a period 

Homolog 

Theresa Edelman 1 , Katherine McCulloch 1 , Angela Barr 2 , Christian Frokjaer-Jensen 3 , 

Erik Jorgensen 3 , Ann Rougvie 1 

1 University of Minnesota, Minneapolis, MN, USA, 2 University of Washington, 

Seattle, WA, USA, 3 University of Utah, Salt Lake City, Utah, USA 

Many events must be precisely timed and coordinated during the development of multicellular 

organisms. C.elegans is a premier system with which to identify genes that temporally regulate 

development. Disruption of these heterochronic genes typically result in either precocious 

or retarded defects, as a consequence of the skipping or reiteration of certain stage specific 

programs, respectively. One interesting player in the heterochronic gene pathway is lin-42, 

the C. elegans homolog of the fly and mammalian circadian clock gene period. lin-42 lossof-function 

alleles cause precocious defects, however the null phenotype is unknown. The 

lin-42 genomic locus is complex in that it produces four different isoforms, two of which do not 

overlap. All reported lin-42 alleles leave at least one isoform intact, complicating genetic analysis 

and making it difficult to place lin-42 in the heterochronic gene pathway. We used MosDEL 

technology to delete the entire coding region, generating a lin-42(0) allele. lin-42(0) animals 

present developmental timing defects that are more severe than previously characterized 

alleles or lin-42(RNAi). The molting defect is also severe causing early larval lethality. Further 

genetic and molecular studies with the lin-42(0) allele will lead to a better understanding of 

the role lin-42 plays in development. 

Contact: brixx001@umn.edu 

Lab: Rougvie 


103


SWI/SNF is Required to Maintain Memory of Adaptation to Hydrogen 

Sulfide 

Emily Fawcett1,2 , Dana Miller1 1Department of Biochemistry, University of Washington, Seattle, WA, USA, 

2Molecular and Cellular Biology Graduate Program, University of Washington, 

Seattle, WA, USA 

Rapid detection and response to external stress is critical for short-term survival in all 

organisms. In some situations, responses to environmental conditions result in long-lasting 

epigenetic changes, or “memories”, that allow for a more rapid or efficient response to 

subsequent stresses. We discovered that in the nematode C. elegans, transient exposure 

to the gas hydrogen sulfide (H 2S) results in a memory that protects against H 2S toxicity later 

in life. In a candidate screen, we identified the SWI/SNF chromatin-remodeling complex as 

required for persistence of H 2S memory. Our data demonstrate that the SWI/SNF complex 

allows for a robust transcriptional response to high H 2S in adapted animals. Therefore, we 

propose that formation of a memory to H 2S establishes an altered epigenetic landscape that 

allows for protection against subsequent stress. We propose that the SWI/SNF complex 

functions in response to H 2S memory to stabilize the altered landscape, maintaining phenotypic 

diversity. Our work establishes a great model for studying the fundamental underpinnings of 

an environmental-induced phenotypic plasticity. 

Contact: efawcett@uw.edu 

Lab: Miller 

104 



Diet & Environment Affect Oxygen-Deprivation Survival in C. elegans 

Anastacia Garcia, Pamela Padilla 

University of North Texas, Denton, TX, USA 

Oxygen deprivation plays a principal role in the pathology of a number of human diseases 

including stroke, cardiac dysfunction and pulmonary disease. Progression of these health 

issues is influenced by diet, environment and/or genetics. Consequently, there is interest in 

understanding the relationship(s) between diet, environment, genotype and the survival of 

oxygen deprivation. Our previous studies have shown that diet and environment affect C. 

elegans anoxia survival rate. We hypothesize that media supplemented with carbohydrates 

(glucose or fructose) will affect response to and survival rate of anoxia exposure and that 

this response can be modulated genetically. We determined that wild-type animals grown 

with the addition of glucose had a significant decrease in anoxia survival rate. Additional 

methodologies are being used to determine if the glucose-induced anoxia sensitivity observed 

in wild-type animals is due to direct and/or indirect effects. Given that different E. coli strains 

display differences in carbohydrate content and ability to metabolize sugars, different strains 

of E. coli (OP50, ΔPTS OP50, & HT115) are being used to assay whether or not food source 

in conjunction with added sugar will differentially influence anoxia survival rate in C. elegans. 

Moreover, the glucose-induced anoxia sensitivity phenotype is suppressed by mutations in 

genes involved with highly conserved pathways including insulin-like signaling and O-GlcNAc 

post-translational modification (PTM) of proteins. Both daf-16 (mu86) and oga-1 (ok1207) 

mutant strains are able to partially suppress the glucose-induced anoxia sensitivity phenotype, 

suggesting that carbohydrate metabolism and PTMs have a role in oxygen-deprivation survival. 

This work will provide a greater understanding of the association between diet, environment, 

genetics and oxygen deprivation responses; and has relevant implications to human health 

related issues including cardiac dysfunction and diabetes. 

Contact: anastaciagarcia@my.unt.edu 

Lab: Padilla 


105


Transcriptional Regulation in the Oxidative Stress Response 

Grace Goh, Ada Kwong, Stefan Taubert 

University of British Columbia, Vancouver, Canada 

Proper transcription is required for organisms to respond to a multitude of external and 

internal signals. One player in transcriptional regulation is the Mediator, a large multi-protein 

complex that acts as a transcriptional coregulator. The Mediator is composed of ~25-30 subunits, 

some of which are required for basal transcription whereas others regulate transcription 

in a gene-specific manner. In the nematode Caenorhabditis elegans, the Mediator subunit 

MDT-15 is required for detoxification in response to certain xenobiotics and heavy metals. 

By comparing MDT-15-dependent genes to genes required for the response to oxidative 

stress, we found that several MDT-15 regulated genes, e.g. UGTs and GSTs, are induced by 

the stable organoperoxide tert-butylhydroperoxide(t-BOOH). Here, we present evidence that 

MDT-15 is required for the oxidative stress response upon t-BOOH exposure. We postulate 

that this response requires interactions between MDT-15 and at least two transcription factors. 

Interestingly, a number of our candidate transcription factors are also known to alter or increase 

fat content, leading us to hypothesize that the t-BOOH response, and perhaps the response 

to oxidative stress in general, is linked to lipid metabolism. 

Contact: graceg@cmmt.ubc.ca 

Lab: Taubert 

106 



Disruption of the ire-1/xbp-1 UPR Pathway Induces ER stress and 

Attenuates the Production and Processing of Secreted Proteins Such 

as Insulin 

Modi Safra 1 , Cynthia Kenyon 2 , Sivan Henis-Korenblit 1 

1 Bar-Ilan University, Ramat-Gan, Israel, 2 UCSF, San Francisco, CA, USA 

The insulin/IGF-1 signaling pathway is a central pathway that controls many fundamental 

biological processes. While much attention has been focused on the pathways and effectors 

downstream of the insulin/IGF receptor, little is known about the molecular mechanisms that 

regulate the level of secreted insulin in the body cavity of the animal. As the production of 

insulin generates a biosynthetic load on the endoplasmic reticulum (ER), it is plausible that 

ER stress response pathways regulate insulin production. 

To test this hypothesis, we investigated how inactivation of conserved ER stress response 

genes affects the expression of insulin in the model organism C. elegans. Using a strain 

expressing a GFP labeled insulin, we discovered that inactivation of the ER stress response 

genes ire-1 or xbp-1 altered insulin expression such that overall insulin levels significantly 

increased while the levels of circulating insulin were reduced compared to wild-type animals. 

How might inactivation of the ER stress-response gene ire-1 regulate insulin expression? 

One plausible model is that the ire-1/xbp-1 arm of the UPR is essential for maintaining protein 

folding homeostasis in the secretory pathway even under basal physiological conditions (in the 

absence of external ER stress). Thus, in their absence, production and processing of protein 

passing through the secretory pathway is severely disrupted. Consistent with this model we 

discovered that protein folding in the ER of ire-1/xbp-1 mutants is defective. Furthermore, 

we found that misfolded proteins cannot be cleared from the ER, leading to the activation of 

alternative ER stress response pathways. Finally, we found that even when correctly folded 

proteins are produced in ire-1(-) cells, they remain constrained in the ER and do not reach the 

secretory granules, not to mention the body cavity of the animal. 

In summary, our findings uncover an essential role for the ire-1/xbp-1 arm of the UPR in 

maintaining protein folding homeostasis in the secretory pathway under basal physiological 

conditions in the adult C. elegans. At the organism level, this implies that in the absence of ire- 

1 multiple important biological processes based on long-range signaling within the organism 

may be severely disrupted. 

Contact: sivankorenblit@gmail.com 

Lab: Henis-Korenblit 


107


The Role of C. elegans BRAP-2 in Regulation of the Oxygen Radical 

Detoxification Response 

Queenie Hu 1 , Lesley MacNeil 2 , Marian Walhout 2 , Terry Kubiseski 1 

1 Department of Biology, York University, Toronto, ON, Canada, 2 Program in 

Gene Function and Expression and Program in Systems Biology, University of 

Massachusetts Medical School, Worcester, MA 

The C. elegans BRCA-1-associated protein 2, BRAP-2, has been identified to have a role in 

preventing an inappropriate response to reactive oxygen species. A deletion mutant of brap-2 

is sensitive to oxidizing conditions, resulting in developmental larval arrest or lethality. We are 

interested in obtaining a better understanding BRAP-2 and its signaling pathway involved in the 

oxidative stress response. We have found that brap-2(ok1492) mutant displays an enhanced 

gst-4 expression in the intestine and hypodermis and that this enhancement is dependent on 

the transcription factor SKN-1. Although the exact mechanism of BRAP-2/SKN-1 regulation 

requires further investigation, our results indicate that BRAP-2 physically interacts with both 

LET-60/Ras and KSR-1/KSR-2, suggesting that the MAPK is the pathway involved in the 

regulation of SKN-1 by BRAP-2. 

In order to identify genes that function in the BRAP-2/SKN-1 detoxification pathway, we 

have used a genetic approach to help identify other novel regulatory components. An RNAi 

suppression screen, using a transcription factor library, was used to identify factors required 

for the enhanced gst-4::gfp expression in the brap-2(ok1492) strain. We have identified twenty 

suppressors that potentially represent either a novel transcription factor or co-activator of SKN-1 

to promote its biological effect. We are currently validating the candidate genes identified from 

this screen. Preliminary results indicate that the ELT-3 GATA transcription factor is required 

for enhanced gst-4 expression in brap-2(ok1492). Taken together, these results suggest a 

model where BRAP-2 acts as negative regulator of KSR and MAPK activity on SKN-1/ELT-3 

dependent gst-4 expression. 

Contact: qniehu@yorku.ca 

Lab: Kubiseski 

108 



Epigenetic regulation of stress response in C. elegans 

Moonjung Hyun, Young-Jai You 

Department of Biochemistry and Molecular Biology, Richmond, Virginia 

Commonwealth University 

Stress induces changes in physiology. In harsh environment, C. elegans undergoes major 

developmental changes to become a dauer, a dormant form to endure stress. Here we report 

that two known tumor suppressor genes, BLIMP1 and Metastasis Associated protein (MTA), 

interact to epigenetically regulate dauer formation downstream of TGFβ signal; knockdown of 

blmp-1 expression in daf-7 mutants is lethal as the mutants enter dauer stage. The levels of 

both mRNA and the protein of blmp-1 are highly upregulated in L2D stage in daf-7 mutants, 

supporting the specific role of blmp-1 in dauer formation. From an RNAi screen of histone 

modification and nuclear remodeling factors, we isolated lin-40, a homolog of mammalian 

MTA whose RNAi phenocopies the lethality we found in blmp-1;daf-7. From candidate gene 

approach, we found that BLMP-1 and MTA regulate common targets including the nuclear 

hormone receptor nhr-85, a homolog of human NR1 subfamily, which regulates molting in 

worms and insects and circadian rhythm in mammals. Taken together, we discovered a novel 

epigenetic mechanism to regulate stress response in worms that is conserved in tumorigenesis 

in mammals. 

Contact: mhyun@vcu.edu 

Lab: You 


109


The Role Of daf-2 Pathway In Primary, Secondary, And Delayed 

Hypoxic Injury 

Euysoo Kim, Chun-Ling Sun, Michael Crowder 

Washington University School of Medicine, St. Louis, (MO), USA 

Neurons and cardiac myocytes die secondary to hypoxic injury and the resultant strokes 

and myocardial infarctions are together the leading cause of US mortality. Yet, no cytoprotective 

therapy is approved for hypoxic/ischemic injury. Mechanisms underlying hypoxia resistance 

have been studied by discovery of hypoxia resistant mutants from various forward genetic 

screens. The first C. elegans mutant discovered to confer hypoxic resistance was a reductionof 

function mutant of the insulin/IGF receptor homolog, daf-2. While some of the mechanisms 

whereby daf-2 regulates hypoxic sensitivity have been defined, basic aspects of the daf-2 

mechanism such as what cell types it protects and when it regulates hypoxic injury relative to 

the actual insult are unknown. Answering these questions has been hindered by limitations of 

our whole animal death assay that is an all or none endpoint. 

To make a cell specific and delayed hypoxic injury model, we made use of rars-1 (gc47) 

mutation, which was previously shown to mediate hypoxic resistance. RARS-1 is an arginyltRNA 

synthetase expressed in all C. elegans cells. In the background of gc47, we expressed 

a rescuing wild-type copy of rars-1 in pharyngeal myocytes thereby making them selectively 

sensitive to hypoxia. During a 4 day recovery period after hypoxic incubation, we observed 

pathology and behavioral deficits in the pharynx and subsequently in the whole body, suggestive 

of primary, secondary, and delayed hypoxic injury. Systemic RNAi of daf-2 significantly blocked 

the Unc and delayed organismal death phenotypes. Reduced necrotic bodies were observed in 

the pharynx of daf-2 RNAi-fed animals. Interestingly, daf-2 RNAi applied only after the hypoxic 

incubation also reduced necrosis in the pharynx and mildly blocked organismal death. Cellspecific 

expression of genes downstream of daf-2 in this model to restrict the action of daf-2 to 

either the primary or secondary hypoxic injury target will reveal which cell types are important 

for daf-2 mediated hypoxic sensitivity. 

Contact: kime@morpheus.wustl.edu 

Lab: Crowder 

110 



The Influence of Endoplasmic Reticulum Stress on the Dauer 

Developmental Decision in C. elegans 

Warakorn Kulalert, Dennis Kim 

MIT, Cambridge, MA, USA 

Upon encountering unfavorable conditions such as starvation, crowding, and high 

temperature, C.elegans larvae arrest in a dauer developmental stage. Dauer larvae are 

non-aging and resistant to a broad array of physiologic insults. Several conserved pathways, 

such as insulin/IGF and TGF-beta, regulate dauer entry and maintenance. We propose that 

accumulation of unfolded proteins in the endoplasmic reticulum operates as a physiological 

response to adverse stimuli, influencing the dauer developmental decision. Administration of 

agents that disrupt protein folding in the ER such as tunicamycin promoted dauer formation in 

a number of dauer-constitutive genetic backgrounds. Furthermore, mutants deficient in xbp-1, 

which encodes a bZIP transcription factor required for the Unfolded Protein Response (UPR), 

formed rare dauers under non-starvation condition. xbp-1 loss of function also enhanced dauer 

formation In the dauer-constitutive daf-1 mutants. The genetic analysis suggests that global ER 

stress caused by defective UPR promotes dauer formation, or that xbp-1 suppresses dauer 

formation. We are currently dissecting the molecular mechanisms of how the UPR contributes 

to regulation of the dauer decision. 

Contact: kulalert@mit.edu 

Lab: Kim 


111


PKC-2 in Peroxide mediated Stress and Aging 

Marianne Land1,2 , Charles Rubin2 1 2 New York Institute of Technology, Old Westbury, NY, US, Albert Einstein Col. 

Med., Bronx, NY, US 

Protein kinase C2 (PKC-2), which is activated by diacylglycerol (DAG) and Ca 2+ , is 

widely expressed in the nervous system and non-neuronal tissues. However, substrates and 

functions PKC-2 are incompletely understood. Candidate PKC-2 effectors were identified by 

differential in gel electrophoresis, using animals in which PKC-2 was elevated 40-fold (pkc- 

2(40x)). PRDX-2, a 2-Cys peroxiredoxin exhibited increased negative charge, consistent 

with increased phosphorylation, in pkc-2(40x) nematodes. 2-Cys peroxiredoxins catalyze 

peroxide reduction, thereby diminishing toxic oxygen species generated by metabolism, 

signaling pathways and various physical and biological stresses. A PRDX-2 deletion mutant, 

prdx-2(gk169), suppressed the cryophilic phenotype of pkc-2(40x) animals and elicited an 

athermotactic phenotype. pkc-2 null animals share this phenotype. Animals lacking PKC-2 or 

PRDX-2 have similarly reduced life spans and increased sensitivities to peroxide-mediated 

killing. The longevities of PKC-2 and PRDX-2 deficient C. elegans and prdx-2(gk169);pkc- 

2(ok328) double mutants are similar, suggesting the two proteins act in a common pathway. 

Animals overexpressing PKC-2 also have a reduced lifespan, indicating that PKC-2 activity 

must be maintained in a limited dynamic range to ensure normal ageing. 

Purified PRDX-2 was phosphorylated to high stoichiometry by a prototypical Ca 2+ , DAG 

dependent PKC in vitro. Site directed mutagenesis identified the PKC phosphorylation site 

in PRDX-2b as DpTIK (amino acids 183-186). Phospho-mimetic and non-phosphorylatable 

PRDX-2 mutants will be expressed in vivo to reveal the physiological relevance of the 

PKC-2 target site. 

Contact: mland@nyit.edu 

Lab: Rubin 

112 



High-throughput screening for small molecule modulators of SKN-1 

Chi Leung 1 , Siobhan Malany 2 , Andrew Deonarine 1 , Ying Wang 1 , Keith Choe 1 

1 University of Florida, Gainesville (FL), 2 Sanford-Burnham Medical Research 

Institute at Lake Nona, Orlando (FL) 

Small molecules are extremely important research and therapeutic tools. Advances 

in chemistry and robotics have resulted in enormous small molecule libraries (>1 million 

compounds) available for high-throughput screening of specific biological processes. Although 

in vitro and cell-based assays can be robust and specific, hit compounds are often found to be 

inappropriate for in vivo use (e.g., toxicity or poor accumulation). Therefore, there is a need for 

in vivo animal screening systems. With support from the NIH Molecular Libraries Program, we 

have developed an in vivo fluorescent-based 1536-well plate assay for measuring activity of 

the stress-inducible transcription factor SKN-1. Multidrug resistance is a growing problem in 

parasitic nematodes that is poorly understood. SKN-1 regulates multiple detoxification genes, 

mediates resistance to toxins, and is present in diverse parasitic nematodes. Pharmacological 

compounds that target SKN-1 would provide new tools for studying multidrug resistance in 

non-model nematodes. We completed a pilot screen of the Library of Pharmacologically Active 

Compounds and are currently screening the NIH small molecule library of ~360,000 compounds. 

We are also developing counter screens to eliminate toxic and non-specific compounds. This 

work is funded by NIH grant R21NS067678-01. 

Contact: leungchikwan@gmail.com 

Lab: Choe 


113


Multisite phosphorylation fine-tunes SKN-1 activity by modulating 

interactions with WDR-23 and target DNA 

Chi Leung 1 , Koichi Hasegawa 2 , Keith Choe 1 

1 University of Florida, Gainesville (FL), 2 Chubu University, Japan 

Cap ‘n’ collar (CNC) transcription factors regulate development, stress resistance, and 

longevity in animals ranging from nematodes to mammals. Molecular regulation involves 

ubiquitin ligases and several protein kinases, but it is unclear how these diverse signals are 

integrated. WDR-23 is a WD40-repeat protein that interacts with the single C. elegans CNC 

(SKN-1) to presumably target the transcription factor for proteasomal degradation. SKN-1 is also 

directly regulated by GSK-3, p38 MAPK, and SGK-1/AKT-1/2 insulin-like signaling pathways. 

To understand how these signals are integrated, we are defining biochemical interactions 

between WDR-23, SKN-1, and SKN-1 target DNA with and without phosphorylation of multiple 

SKN-1 residues. A forward genetic screen for disinhibition of the SKN-1 target gene gst-4 

found a dominant allele of SKN-1 and several missense alleles of WDR-23. Yeast 2-hybrid 

analysis indicates that all of these mutations disrupt interactions between SKN-1 and WDR- 

23. Preliminary data also suggest that WDR-23 can inhibit interactions between SKN-1 and its 

target DNA. Site-directed mutagenesis studies indicate that phosphorylation of SKN-1 alters its 

interactions with both WDR-23 and target DNA and that p38 MAPK sites are dominant to GSK-3 

sites, as was previously shown in vivo [An et al., 2005 PNAS 102(45):16275]. Functional amino 

acids map within two adjacent blades of a predicted WDR-23 β-propeller and to two regions of 

SKN-1 providing structural insight into signaling. Our studies suggest that a complex multisite 

phosphorylation “code” regulates cellular detoxification by modulating interactions between 

SKN-1, its repressor protein, and target DNA. This mechanism may permit fine-tuning of CNC 

activity to match specific demands set by stress, metabolism, development, and ageing. This 

work is funded by NSF grant IOS-1120130 to KPC. 

Contact: leungchikwan@gmail.com 

Lab: Choe 

114 


Contact: jrice@bmcc.cuny.edu 

Lab: Savage-Dunn 


Functions of CLIC proteins in C. elegans 

Jun Liang1 , Cathy Savage-Dunn2 1 2 Borough of Manhattan Community College/CUNY, New York, Queens College/ 

CUNY, New York 

Chloride intracellular channel proteins (CLIC) are multifunctional proteins that are 

homologous to the glutathione S-transferase family. Most of research is focused on CLIC4 who 

is ubiquitously expressed in most mammal cells. CLIC4 regulates cellular stress, apoptosis, 

carcinogenesis, angiogenesis, and macrophage innate response. Cellular stress molecules 

such as DNA damaging agents, transcription inhibitors, translation inhibitors, and TNF-α induce 

endogenous CLIC4 to translocate from cytoplasm to nucleus. Mammalian Schnurri-2 is required 

for CLIC4 nuclear translocation in response to TGF-β but not required for CLIC4 nuclear 

function. Schnurri-2 is a transcription factor in the BMP pathway and its worm homologous is 

SMA-9. 

In C. elegans, DBL-1/TGF-β signaling components includes dbl-1, sma-2, sma-3, sma-4, 

and sma-9 etc. Their mutants are viable compare with that of other organisms, which allow 

research being performed at a whole living animal level. There are two CLIC homologs in C. 

elegans: EXL-1 and EXC-4. exc-4 mutants develop cysts in the excretory canal, while exl-1 

mutants do not have any observable phenotypes. However, other functions of EXC-4 and EXL- 

1 are unknown, in particular whether they interact with SMA-9 in C. elegans. To address this 

issue, we analyzed integrated EXL-1::GFP lines in wild type background. Strong fluorescence 

was observed in intestine cells, which is consistent with previous study. EXL-1::GFP indeed 

translocated into the nucleus at 37°C. However, whether it is regulated by SMA-9, as well as 

other TGF-β signaling components, is unknown. In the future, we will focus on these genetic 

interactions among them. 


115


Mouse Nmnat1 protects C. elegans from hypoxic death 

Xianrong Mao, C. Michael Crowder 

Washington University in St Louis 

Wallerian degeneration slow (Wlds) is a naturally occurring mouse mutation created by a 

chimeric fusion between Ube4b gene and nicotinamide mononucleotide adenylyltransferase 1 

gene (Nmnat1, which is a NADsynthethase). Expression of Wlds or a cytoplasmically-localized 

Nmnat1(cyt-Nmnat1) strongly protects mouse and fly axons from degeneration after harmful 

insults. Recently, cyt-Nmnat1 was found to protect from hypoxic neuronal injury in a mouse 

model of stroke. Despite considerable investigation in mouse and fly, the mechanism for cyt- 

Nmnat1 protection from axonal degeneration or hypoxic injury is completely obscure. We 

expressed mouse cyt-Nmnat1(m-cyt-Nmnat1) in C. elegans under the control of a ubiquitous 

or pan-neuronal promoter and asked if it protected worms from hypoxic injury. Both neuronal 

and ubiquitous m-cyt-Nmnat1 strongly increased whole worm survival after a hypoxic insult. 

Ubiquitous overexpression of a C. elegans Nmnat1 homolog F26H9.4 also increased hypoxic 

survival in the worm; the sterile phenotype of a null allele of F26H9.4 was rescued with 

ubiquitous m-cyt-Nmnat1, consistent with functional homology. Besides hypoxia resistance, 

m-cyt-Nmnat1 expression in neurons produced a strong chemotaxis defective phenotype and 

ubiquitous expression gave a partial sterility phenotype. We previously found that restoring 

protein homeostasis is critical to recovery from hypoxia in C. elegans. In testing various 

protein homeostasis pathways, we found that the mitochondrial ABC transporter gene haf-1 

was required at least partially for all of the phenotypes produced by m-cyt-Nmnat1 expression 

in worm. HAF-1 is thought to be necessary for the transport of mitochondrial degradation 

peptides to the cytoplasm as part of the mitochondrial unfolded protein response (mito-UPR). 

This result suggests that Nmnat1 may function to regulate the mito-UPR as part of its hypoxia 

protective mechanism. 

Contact: maox@wustl.edu 

Lab: Crowder 

116 



Gene silencing based functional analysis of C. elegans cytochromes 

P450: roles in biotransformation, fat storage and eicosanoid formation 

Ralph Menzel 1 , Christian Steinberg 1 , Wolf-Hagen Schunck 2 

1 Humboldt-University at Berlin, Germany, 2 MDC Berlin, Germany 

The genome of the nematode Caenorhabditis elegans contains 75 full length cytochrome 

P450 (CYP) genes whose individual enzymatic and biological functions are largely unknown 

yet. Using microsomes isolated from adult worms, we found that C. elegans produces spectrally 

active CYP proteins that display typical CO-difference spectra. The microsomes also showed 

NADPH-cytochrome c reductase activity, silencing of emb-8 expression resulted in a loss of this 

activity. Expression of emb-8 was also essential for all CYP-dependent activities measured in 

this study. To identify the CYP components of specific monooxygenase systems, we performed 

systematic gene silencing by RNAi and used cyp-mutant strains. 

Searching for CYP isoforms involved in the biotransformation of xenobiotics, we found 

that CYP-14A3 and CYP-14A5 are required for the hydroxylation of an ortho-substituted, 

non-coplanar tetrachlorbiphenyl (PCB52) to C3-, C4- and/or C6-hydroxy-PCB52. In contrast, 

isoforms of the CYP-35A subfamiliy, which are also induced by PCB52 and other xenobiotics, 

could be assigned to the fat storage pathway. Individual gene silencing of cyp-35A2, 3, 4, and 5 

resulted in a dramatic decrease of intestinal fat content of well fed young adults. Both cyp-14A 

and cyp-35A isoforms are expressed in the intestine, as shown by GFP reporter constructs. 

Searching for CYP isoforms involved in eicosanoid formation, we identified CYP- 

29A3 and CYP-33E2 as the major isoforms contributing to the endogenous metabolism of 

eicosapentaenoic acid (EPA) and arachidonic acid (AA) in C. elegans. Co-expression of CYP- 

33E2 with the human NADPH-CYP-reductase in insect cells resulted in the reconstitution of an 

active microsomal monooxygenase system that metabolized EPA and, with lower activity, also 

AA to specific sets of regioisomeric epoxy- and hydroxy-derivatives. Using worms carrying a 

cyp-33E2 promoter::GFP-reporter construct, we found that CYP-33E2 is exclusively expressed 

in the pharynx, where it is predominantly localized in the marginal cells. RNAi-mediated cyp- 

33E2 expression silencing as well as treatments with inhibitors of mammalian AA-metabolizing 

CYP enzymes, significantly reduced the pharyngeal pumping frequency of adult worms. These 

findings suggest that CYP-eicosanoids known to modulate the contractility of cardiomyocytes 

and vascular smooth muscle in mammals serve as regulators of pharyngeal activity and feeding 

behavior in C. elegans. 

Contact: ralph.menzel@biologie.hu-berlin.de 

Lab: Menzel 


117


Deciphering the microRNA responses to High Temperature Stress 

Camilla Nehammer 1 , Agnieszka Podolska 1 , Konstantinos Kagias 1 , Sebastian 

Mackowiak 3 , Nikolaus Rajewsky 3 , Roger Pocock 1 

1 BRIC, Copenhagen, 3 Max-Delbruck-Center, Berlin 

Living organisms are constantly exposed to changing environments and the ability to 

maintain homeostasis whilst exposed to stress is essential for survival. Therefore, rapid 

responses to stress, such as high temperature, are crucial in order to avoid detrimental stress 

induced effects. MicroRNAs are rapidly acting regulatory elements which can fine-tune gene 

expression when required. Thus, microRNAs are excellent candidates to study the regulation 

of stress response pathways in C. elegans. 

We performed RNA-seq analysis to identify microRNAs that are regulated in response to 

high temperature. We exposed L4 animals to 35°C temperature stress for 4 hours and detected 

48-down and 11 up-regulated (> 2-fold) microRNAs compared to control. Of these we identified 

six novel microRNAs. The detection of a number of microRNAs previously associated with 

stress responses in C. elegans, including miR-71, miR-239 and miR-246, is encouraging and 

strengthens the reliability of this high throughput sequencing approach. 

Temperature stress regulated candidates including predicted-novel microRNAs are currently 

being validated by RT-qPCR. Furthermore, our phenotypic analysis of microRNA mutant strains, 

of those microRNAs regulated by high temperature, revealed a number of promising stress 

resistant and stress sensitive microRNAs. These data provide a platform for further in-depth 

analysis of the roles of these microRNAs in stress response pathways in C. elegans. 

Contact: cne@bric.ku.dk 

Lab: Pocock 

118 



Transmission of a Q/N-Rich Prion Domain Between C. elegans 

Tissues Causes an Extreme Form of Proteotoxicity 

Carmen Nussbaum-Krammer 1 , Kyung-Won Park 2 , Liming Li 2 , Ronald Melki 3 , Richard 

Morimoto 1 

1 Northwestern University, Evanston, (IL), USA, 2 Northwestern University, Chicago, 

(IL), USA, 3 CNRS, Gif-sur-Yvette, France 

The yeast prion protein Sup35 harbors a glutamine/asparagine (Q/N)-rich sequence motif 

that can adopt alternative self-propagating conformations. Similar Q/N-rich regions have been 

found in a number of genetic modifiers of neurodegenerative disorders, however their properties 

are poorly understood in metazoans. Here, we have examined the behavior of the Q/N-rich 

prion domain (NM) from Sup35 expressed in Caenorhabditis elegans. NM formed multiple 

classes of aggregates with distinct biophysical properties associated with a severe cellular 

and organismal toxicity. Both aggregation and toxicity phenotypes were strictly dependent on 

the length of NM oligorepeats and led to profound alterations in mitochondrial morphology not 

only in NM expressing muscle cells but also comprised non-expressing tissues. These cell 

non-autonomous effects correlated with the spreading of misfolded proteins. Taken together, 

this C. elegans model demonstrates that Q/N-rich prion domains have the potential to transmit 

from cell-to-cell in metazoans suggesting a possible mechanism for the prion-like propagation 

of pathology in diverse neurodegenerative diseases. 

Contact: c-krammer@northwestern.edu 

Lab: Morimoto 


119


The affect of carbohydrate diet, metabolism, germline function and 

age on oxygen deprivation response and survival in C. elegans 

Pamela Padilla 1 , Anastacia Garcia 1 , Jo Goy 2 , Mary Ladage 1 

1 University of North Texas, 2 Harding University, Searcy AR 

Oxygen deprivation, which is central to many human-health related issues (Ex: stroke, 

cardiac and pulmonary disorders) occurs frequently in the elderly and can have a more 

detrimental affect on individuals who are diabetic or obese. We are using Caenorhabditis 

elegans to examine how environment, diet, age and genotype influences oxygen deprivation 

response and survival. One-day old, wild-type adult C. elegans fed the standard OP50 diet and 

grown at 20C will survive severe oxygen deprivation (anoxia) for at least 24 hours however 

this survival rate is severely decreased if anoxia exposure is longer than three days. Factors 

associated with long-term anoxia tolerance include age (3-5 day old adults hermaphrodites 

survive long-term anoxia), a decrease in ovulation rate, development at 25C instead of 20C, a 

diet of HT115 E. coli or pretreatment with the diabetic drug metformin. Long-term anoxia survival 

rate is associated with an increase in carbohydrate stores (glycogen, treholose) in the intestine 

however a glucose-supplemented diet leads to sensitivity to anoxia exposure, suggesting that 

a homeostatic balance of carbohydrate stores is important for oxygen deprivation survival. 

Analysis of mutants identified the following signaling pathways as influencing anoxia survival: 

insulin-like signaling (daf-2/daf-16), developmental pathways that alter germline function (glp- 

1), carbohydrate metabolism (aak-2), hexosamine signaling (oga-1) and methyglycoxal protein 

modifications. Insulin-signaling, carbohydrate homeostasis, oxidative stress and hexosamine 

signaling impact diabetes in humans suggesting that C. elegans can be used as a cellular and 

genetic model to understand the relationship between diet, metabolism, oxygen deprivation 

stress and disease states such as type II diabetes. 

Contact: Pamela.Padilla@unt.edu 

Lab: Padilla 

120 



Understanding Hypoxia-dependent, HIF-independent Pathways in 

C.elegans 

Divya Padmanabha, Young-Jai You, Keith Baker 

Virginia Commonwealth University Health Systems, Richmond (VA), USA 

The interface of metabolism and hypoxia in disease progression has been increasingly 

explored in recent years. Several transcriptional activators are markedly induced by oxygen 

deprivation. Cellular and systemic responses to hypoxia have been extensively studied in the 

context of the transcription factor hypoxia inducible factor (HIF), a critical regulator of angiogenic 

and glycolytic genes in hypoxia. Interestingly, gene expression studies provide clear evidence 

of HIF-independent pathways that are critical for adaptation to hypoxia 1 . However, relatively 

little is known about the oxygen sensors and regulatory pathways that mediate transcriptional 

responses independent of HIF. The nematode Caenorhabditis elegans has proven to be a 

powerful model system to study evolutionarily conserved signaling pathways that regulate 

hypoxia responses. Hence, we are conducting an RNAi screen to identify transcription factors 

regulating HIF-independent genes in hypoxia. Accordingly, we have generated GFP reporter 

animals with a gene that is induced in hypoxia in a HIF-independent manner. We posit that the 

screen will comprehensively identify key components that play a role in C.elegans adaptation 

to hypoxia, independent of HIF. 

1. ShenC, Nettleton D, Jiang M, Kim SK, Powell-Coffman JA. Roles of the HIF-1hypoxiainducible 

factor during hypoxia response in Caenorhabditis elegans. JBiol Chem. 2005 

Contact: padmanabhad@mymail.vcu.edu 

Lab: Baker 


121


Osmotic Stress Resistance and Cuticle Defects – Two Symptoms, One 

Cause 

Anne-Katrin Rohlfing 

University of Potsdam, Potsdam, Germany 

The strain osm-8(n1518) is a well defined example of osmotic stress resistant (osr) mutants, 

which exhibit a constitutive active osmotic stress response. A mutation in the mucin-like gene 

osm-8 disrupts osmoregulatory physiological processes and leads to a constant expression of 

the enzyme gpdh-1. GDPH-1 triggers the synthesis and accumulation of high amounts of the 

osmolyte glycerol within the hypodermis and intestine, as we were able to demonstrate before. 

The OSM-8 protein is expressed in the hypodermis and is most likely secreted into the 

extracellular matrix (ECM). In the ECM, OSM-8 is supposed to act as part of an osmosensory 

structure and to activate the osmotic stress response via the transmembrane protein PTR-23, 

similar to the osmosensory mucins Hkr1 and Msb2 in S. cerevisiea. However, there is evidence 

for a second function of osm-8 in cuticle formation. osm-8 expression peaks before each molt 

and before the final molt in developing C. elegans. This cyclic expression pattern correlates 

strongly with expression pattern seen in genes typically connected to molt, like dpy-7. Unlike 

in dpy strains the typical surface morphology with regular, cirumferential-oriented furrows and 

annuli was still visible by scanning electron microscopy, as well as are alae. However, the osm- 

8(n1518) cuticle appeared thinner and displayed an altered fine structure as determined by 

transmission electron microscopy. The normal C. elegans cuticle is composed of three layers: 

the cortical layer, middle layer with collagen strut and the basal layer. In osm-8(n1518) the 

basal layer was reduced to the thickness of wildtype cuticle and the struts appeared smaller 

and more electron dense. This phenotype was reversible to some extent by a heat shock 

within in the early L4 state in osm-8(n1518) strains carrying a heat-shock inducible osm-8(+) 

transgene. This treatment also fully reversed the strong osr phenotype of transgenic osm- 

8(n1518) animals back to a normal response to hyperosmotic environment. 

Whether there is a connection between the physiological and the morphological phenotypes 

of osm-8(n1518) or whether they are caused by two distinct functions of one protein has to 

be further investigated. 

Contact: rohlfing@uni-potsdam.de 

Lab: Rohlfing 

122 



Knockdown of Genes Involved in Basic Cellular Functions Impairs 

Mitochondrial ROS Stress Signaling to the Nucleus 

Eva Runkel 1,2 , Shu Liu 2 , Ralf Baumeister 3,2 , Ekkehard Schulze 2 

1 Spemann Graduate School of Biology and Medicine (SGBM), 2 Bioinformatics and 

Molecular Genetics (Faculty of Biology), Albert-Ludwigs-University of Freiburg, 

Germany , 3 Spemann Graduate School of Biology and Medicine (SGBM), FRIAS 

LIFENET, BIOSS 

Reactive oxygen species (ROS) are constant byproducts of mitochondrial respiration that 

under physiological conditions are scavenged by detoxifying enzymes. An increase in ROS 

production, however, requires additional specific regulatory responses preventing mitochondrial 

damage. These responses are mediated by retrograde signaling to the nucleus which we 

monitored using a hsp-6::gfp reporter. 

To mildly increase mitochondrial ROS production, we exposed C. elegans to 0.5 mM 

paraquat. Genome-scaled RNAi screening revealed the mitochondrial unfolded protein 

response (UPR mt ) mediating transcription factor ATFS-1 as essential for the retrograde ROS 

response. 

Knockdown of genes involved in basic cellular mechanisms such as translation and protein 

transport specifically impaired the retrograde ROS response. Remarkably, none of these 

conditions abrogated other stress signaling pathways that evoke the UPR ER , the heat shock 

response or the phase II oxidative stress response, however, a subset of these conditions 

impaired the UPR mt . We hypothesize that a stress status of the worm, which is initiated by 

impairment of basic cellular functions, suppresses the retrograde response towards mild ROS 

stress. Future research will address the hierarchic interplay between these distinguishable 

stress states. 

Contact: eva.runkel@sgbm.uni-freiburg.de 

Lab: Baumeister 


123


The Effects of HIF-1 Over-Activation: Real-Time Assays for Toxin 

Response 

Jenifer Saldanha, Archana Parashar, Santosh Pandey, Jo Anne Powell-Coffman 

Iowa State University, Ames, Iowa, USA 

In animals as diverse as nematodes, fruit flies, and humans, the hypoxia inducible factor 

(HIF) transcription factors affect gene expression changes that enable adaption to hypoxia 

(low oxygen). C. elegans HIF-1 has been shown to have roles in aging, stress resistance and 

neuronal development. HIF-1 activity is regulated by multiple mechanisms. When oxygen 

levels are sufficiently high, the EGL-9 enzyme hydroxylates HIF-1 and thus targets HIF-1 for 

degradation via the VHL-1-mediated proteasomal degradation pathway. EGL-9 also inhibits 

HIF-1 transcriptional activity. Strong loss-of-function mutations in egl-9 confer resistance to 

Pseudomonas aeruginosa PAO1 fast killing. More specifically, the egl-9 mutants are resistant 

to cyanide produced by the bacteria. Other mutations in the HIF-1 pathway also influence C. 

elegans resistance to cyanide. To characterize these phenotypes and to examine the roles 

of other genes in cyanide resistance, we employed an array of genetic tools and microfluidic 

technologies. We have quantitated several behavioral parameters for wild-type and mutant 

strains, and we will present some of these results. Microfluidic platforms and real-time imaging 

enable greater spatio-temporal resolution of the phenotypes, which, in turn, enriches genetic 

analyses of the HIF-1 genetic networks. 

Contact: jenifers@iastate.edu 

Lab: Powell-Coffman 

124 



Exploring Natural Variation of Starvation Resistance and Growth Rate 

Moses Sandrof, Meghan Jobson, L. Ryan Baugh 

Department of Biology, Duke Center for Systems Biology, Duke University 

The majority of studies in C. elegans use strains from a single genetic background. However, 

in the analysis of ecologically relevant traits, it is advantageous to look at strains from an 

array of environmental and evolutionary backgrounds. In theory, natural selection acts in an 

environment-specific manner on phenotypes relating to life history such that relevant traits may 

vary. Our laboratory uses L1 arrest and recovery as a nutritional deprivation model to examine 

trade-offs between stress resistance and growth. We hypothesize that there is an inverse 

relationship between starvation resistance and growth rate among wild isolates, reflecting a 

trade-off in resource allocation. We are investigating starvation survival and growth rate in 

multiple wild-type isolates to characterize phenotypic variation and address this hypothesis. 

Recent work in our lab reveals a variety of epigenetic effects of starvation on growth and stress 

resistance, and we are also investigating natural variation of these epigenetic effects. 

Contact: moses.sandrof@gmail.com 

Lab: Baugh 


125


The Role of the Translation Machinery in Survival from Hypoxia 

Barbara Scott, Chun-Ling Sun, Xianrong Mao, Charles Yu, C. Michael Crowder 

Washington University School of Medicine, St. Louis, Missouri, USA 

A reduction of protein synthesis has been associated with resistance to hypoxic cell death. 

Which components of the translation machinery control hypoxic sensitivity and the mechanism 

for this hypoxia resistance has not been systematically investigated. A reduction in oxygen 

consumption has been widely assumed to be the primary mechanism. Using genetic reagents 

in C. elegans, we examined the effect on organismal survival after hypoxia of knockdown and/ 

or mutation of twelve translation factors functioning at various steps in translation. Reduction-offunction 

of most translation machinery genes significantly increased hypoxic survival, however, 

to varying degrees. Surprisingly, translation rates as measured by FRAP did not correlate with 

hypoxic sensitivity except for reduction-of-function of aminoacyl-tRNA synthetases. Oxygen 

consumption rates correlated weakly with increased hypoxic survival (r 2 = 0.34, p=0.02). 

Hypoxic sensitivity had no correlation with lifespan or reactive oxygen species sensitivity, two 

phenotypes previously associated with reduced translation rates. Misfolded protein sensitivity 

was the only phenotype that strongly correlated with hypoxic sensitivity (r 2 = 0.90, p


The Role of the Ubiquitin-Proteasome System in the Formation of 

Polyglutamine Aggregates 

Gregory Skibinski, Lynn Boyd 

University of Alabama in Huntsville, Huntsville, (Alabama), USA 

The misfolding of soluble proteins and subsequent aggregation is associated with several 

neurodegenerative diseases and is thought to be involved in the pathological process. 

Aggregates in multiple diseases, including polyglutamine (polyQ) aggregates, show positive 

immunostaining for ubiquitin and proteasomes. The ubiquitin-proteasome system, which 

degrades transient and damaged proteins, may be impaired in these diseases and is thought 

to be involved in aggregation. To investigate this, we are using a transgenic line of C. elegans 

developed by Morimoto et al. that expresses an aggregation-prone stretch of glutamine repeats 

(Q82) fused to GFP(green fluorescent protein). We have shown that knockdown of specific E2 

ubiquitin-conjugating (UBCs) enzymes alters the size and frequency of polyQ-GFPaggregates, 

and that ubc-1, ubc-13, and uev-1 are required for ubiquitin colocalization to aggregates 

(Howard et al., BMC Cell Biology2007, 8:32). To view this process in real-time, we are using 

time-lapse microscopy to view aggregation of soluble Q82::GFP into punctate aggregates 

in early-stage C. elegans larvae (Skibinski , Boyd, BMC Cell Biology 2012, 13:10).We have 

observed that the initial in vivo formation of polyQ aggregates in the body wall muscle cells 

occurs over a span of about 1 hour. RNAi of UBCs, most notably ubc-22, affects the rate of this 

initial aggregation, primarily by increasing the steady-state levels of Q82::GFP protein in the cell. 

This may indicate that the initial aggregation event is not directly dependent on ubiquitination 

of aggregating proteins. Beyond this initial phase, aggregation is slower, but RNAi of ubc-1, 

ubc-22, or uev-1 increases this rate. RNAi of ubc-13 reduces this rate. When Q82::GFP is 

co-expressed with an mCherry::ubiquitin fusion protein, the mCherry::ubiquitin colocalizes 

toQ82::GFP aggregates primarily in the late larval stages. FRAP analysis indicates that ubiquitin 

may be mobile within the aggregate. Currently,we are producing a strain expressing Citrine 

fused to proteasome subunit RPT-1, which will extend the analysis of aggregation dynamics 

to the proteasome. 

Contact: greg.skibinski@gmail.com 

Lab: Boyd 


127


C. elegans as a Model to Study Drug-induced Mitochondrial 

Dysfunction 

Richard de Boer, Reuben Smith, Hans van der Spek, Stanley Brul 

University of Amsterdam, Amsterdam, The Netherlands 

To address fundamental questions concerning drug-induced mitochondrial dysfunction, 

Caenorhabditis elegans was applied as a model organism. Several studies have shown the 

occurrence of mitochondrial dysfunction as a consequence of therapeutic drug use, especially 

the drugs used to treat HIV infected individuals. The cause of anti-HIV drug toxicity appears 

to be linked to a common mechanism: a decreased mitochondrial energy-generating capacity 

putatively caused by the secondary inhibition of mitochondrial DNA polymerase γ, resulting 

in the depletion of mitochondrial DNA (mtDNA). However, the exact mechanism behind 

mitochondrial toxicity remains unknown as drug effects are diverse. Most research has been 

done in patient- or cell culture studies, which pose limitations on the experiments that can 

be performed. Progress in this field is highly dependent on the development of a robust and 

accurate model system. 

Using C. elegans as a model system we show a concentration dependent decline in mtDNA 

copies when cultured in the presence of various anti-retroviral drugs. This decline was both 

absolute and relative compared to nuclear DNA. Moreover, exposure to these drugs resulted 

in altered aerobic respiration, increased ROS production and/or a quantifiable disruption of the 

mitochondrial morphological network. The severity of the observed effects is drug-specific and 

concentration dependent. Interestingly, the observed biochemical and morphological effects are 

not necessarily provoked by the same compounds and some of the effects can be alleviated 

by providing supplementation with compounds active on the mitochondrial respiratory chain. 

Since the side-effects of the drugs in patients on anti-retroviral therapy closely resemble 

our observed effects in C. elegans , we conclude that C. elegans is a highly suitable model 

organism to study drug induced mitochondrial dysfunction. Moreover, as C. elegans is a 

highly expedient model system, searching for compounds to alleviate the induced toxicities is 

straightforward. Preliminary results suggest the beneficial effect of supplementation as a way 

of counteracting and alleviating some of these pernicious side-effects. 

Contact: r.l.smith@uva.nl 

Lab: Brul 

128 



Identification of pathways by which a peroxiredoxin influences stress 

resistance reveal (i) its importance for insulin/IGF1-like-signalling 

and (ii) new genes important for phase 2 detoxification gene 

expression, stress resistance and longevity 

Helen Crook, Monika Olahova, Elizabeth Veal 

Newcastle University, Newcastle upon Tyne 

Peroxiredoxins (Prx) are abundant peroxidases with an evolutionarily conserved role in 

longevity. As well as detoxifying peroxides, Prx are important regulators of signal transduction. 

For instance, Prx have a conserved role in promoting the stress-induced activation of p38-related 

MAPK, such as C. elegans PMK-1 [1]. PMK-1 activates the Nrf2-related transcription factor 

SKN-1 to increase expression of phase 2 detoxification genes and oxidative stress resistance 

[2]. However, despite reduced PMK-1 activation, C. elegans lacking the single ortholog of the 

Prx1 tumor suppressor, PRDX-2, express elevated levels of phase 2 detoxification enzymes 

and are hyper-resistant to some forms of oxidative stress [1]. We have undertaken a variety of 

approaches to understand the basis for the increased stress resistance and reduced lifespan 

of prdx-2 mutant C. elegans. We have discovered that the increased activity of the DAF-16 

and SKN-1 transcription factors contribute to their increased stress resistance. Indeed our data 

strongly suggest that PRDX-2 is required for the insulin/IGF1-like (IIS)-dependent inhibition of 

both DAF-16 and SKN-1, thus indicating a hitherto unknown role for Prx in IIS. 

In addition, we have used a genome-wide RNAi screen to identify other genes that are 

important for the increased expression of the SKN-1-target gene gcs-1 in prdx-2 mutant animals. 

Consistent with the important contribution made by SKN-1-regulated genes to longevity, a 

significant number of the genes identified by this screen have been previously identified as 

important for the lifespan-extension associated with reduced IIS [3]. Moreover, we find that 

many of the genes we have identified are also important for stress-induced increases in gcs-1 

expression in wild-type animals. Strikingly, our analysis has revealed that many of these new 

activators of phase 2 detoxification gene expression, including the receptor of activated protein 

kinase C RACK-1, act by novel mechanisms that are independent or downstream from PMK-1. 

We will discuss the important implications of our findings for the role of IIS, the PMK-1/SKN-1 

canonical pathway and Prx in stress resistance and ageing. 

1 Olahova et al (2008) PNAS 105; 19839-44 

2 Inoue et al (2005) Genes & Dev 19;2278-83 

3 Samuelson et al (2007) Genes & Dev 21;2976-94 

Contact: e.a.veal@ncl.ac.uk 

Lab: Veal 


129


Energy Metabolism Abnormality Of Ultraviolet Irradiation Sensitive 

Mutant Rad-8 In C. elegans 

Kayo Yasuda 1 , Michihiko Fujii 2 , Hitoshi Suda 3 , Phillip Hartman 4 , Takamasa Ishii 1 , Naoaki 

Ishii 1 

1 Tokai University, Isehara, Kanagawa, Japan, 2 Yokohama City University, 

Yokohama, Kanagawa, Japan, 3 Tokai University,Nishino, Numazu, Japan, 4 Texas 

Christian University, Fort Worth, Texas, USA 

C. elegans rad-8 has been isolated as an ultraviolet radiation hypersensitive mutant and we 

have also found that this mutant is oxygen hypersensitive. Reactive Oxygen Species (ROS) as 

well as radiation cause cellular damages and result in a variety of diseases including cancer 

and aging. It is well known that most endogenous ROS are produced from mitochondria. 

In order to know whether oxidative sensitivity of rad-8 mutant is correlated with mitochondrial 

oxidative stress, we examined, 1) amount of supeoxide anion (O 2 - ) one of ROS, from 

mitochondria and 2) carbonylated protein as a marker of oxidative stress, 3) apoptosis at 

embryonic stage, 4) growth rate 5) energy metabolism and 6) mitochondrial function. Our 

results showed that the level of O 2 - and the carbonylated protein in mitochondria produced by 

the O 2 - significantly increased compared to N2 wild type. The apoptosis also increased. On 

the other hand, the energy metabolisms and growth rate of rad-8 were lower compared to N2. 

Furthermore, the body size of rad-8 at the adult stage was smaller than N2. 

These data suggested that the function of rad-8 gene is related with mitochondria. It is 

assumed that the energy metabolic abnormality in rad-8 mitochondria leads to increase of 

oxidative stress and apoptosis by the ROS over production. 

Contact: lilac@is.icc.u-tokai.ac.jp 

Lab: Ishii 

130 



Graphite Nanoplatelets and Caenorhabditis elegans: Insights from an 

in vivo Model 

Elena Zanni, Giovanni De Bellis, Maria Bracciale, Alessandra Broggi, Maria Santarelli, 

Maria Sarto, Claudio Palleschi, Daniela Uccelletti 

Sapienza, University of Rome, Italy 

Nanosized particles display unique physical and chemical properties and represent an 

increasingly important material in the development of novel nanodevices which can be used 

in numerous physical, biological, biomedical and pharmaceutical applications.Intriguingly, 

graphene, a single sheet of sp 2 hybridized honeycombcarbon, and graphene-related materials 

such as graphite nanoplatelets (GNPs), have proved to be among the most promising materials 

due to their unique electronic properties, such as an extremely high carrier mobility and a 

linear dispersion relation. 

Here we report an in vivo toxicity assessment of graphite nanoplatelets on the animal 

model Caenorhabditis elegans. Our study pointed out the absence of any acute or chronic 

toxicity of GNPs on the nematodes. Moreover, the genotoxicity has been investigated and no 

effect on C. elegans reproductive potential has been found. In addition, an imaging technique 

based on Fourier Transform Infrared Spectroscopy (FT-IR) mapping was also developed to 

demonstrate the effective GNPs intake inside the nematodes. Such analysis not only indicated 

a GNPs distribution along the whole worm body, but gave evidence of nanoparticles transition 

from the intestine tract to the gonads. 

The ever-growing interest for graphene-based nanoparticles in potential applications such 

as nanomedicine prompted us to investigate the antimicrobial properties of GNPs. Given the 

useful properties offered by the host-pathogen system C.elegans-Pseudomonas aeruginosa 

we assessed the in vivo antimicrobial potential of GNPs. Notably, the nanoplatelets treatment 

of Pseudomonas-infected animals led to a strikingly mortality of worm-colonizing bacteria 

within 30 minutes of exposure. 

We believe that our data obtained by using the animal model C. elegans could optimize 

the experimental validation procedures involved in safety issues. Infact, the combined effect 

of long term biocompatibility, absence of genotoxicity and antimicrobial activity demonstrated 

in nematodes should push to study such properties directly in mammalian models, especially 

those highly predictive for human applications. 

Contact: elena.zanni@uniroma1.it 

Lab: Uccelletti 


131


Cancer-like features could facilitate rapid intracellular growth of a 

natural intracellular parasite in C. elegans. 

Malina Bakowski2 , Amy Ma2 , Christopher Desjardins1 , Christina Cuomo1 , Emily Troemel2 1 2 The Broad Institute of MIT and Harvard, Cambridge, MA, University of California 

San Diego, La Jolla, CA 

Microsporidia are obligate intracellular parasites most closely related to fungi. They are 

ubiquitous in nature, but are poorly understood because of the difficulties in culturing them. 

We found a new species of microsporidia isolated from a wild-caught C. elegans near Paris 

and we named it Nematocida parisii, or nematode-killer from Paris. In addition to this N. parisii 

strain (ERTm1), we found Nematocida infections in wild-caught Caenorhabditis hosts from 

several locations around the world. This Nematocida/Caenorhabditis system provides a unique 

opportunity to study microsporidia infection in a tractable model organism. 

To elucidate the mechanisms of microsporidia pathogenesis we sequenced the genomes 

of three Nematocida strains. We also performed RNA-seq analysis on ERTm1 during infection 

within the C. elegans host to quantify infection dynamics and define the N. parisii transcriptome. 

Microsporidia have the smallest known eukaryotic genomes and, likewise, we find that the 

ERTm1 genome is only 4.1 Mb and contains just 2,661 predicted genes, 95.7% of which 

are expressed during infection of C. elegans based on RNA-seq. We are using this genome 

sequence data, together with other microsporidian genomes, to learn more about mechanisms 

of pathogenesis. 

Microsporidia have a limited metabolic capacity and cannot grow independently, instead 

relying on host cells as sources of energy and macromolecules. However, after they invade 

host cells these parasites can grow extremely rapidly in the intracellular environment. For 

example, N. parisii can grow 220-fold in less than 32 hours inside C. elegans intestinal cells. 

We utilized the microsporidia genome data to develop a model that may explain this swift 

growth. Early during infection N. parisii appears to deliver a key metabolic enzyme into the 

host cell cytoplasm where it could direct the infected cell to enter an anabolic state, generating 

building blocks necessary for cellular proliferation of the parasite, such as nucleosides. We also 

found that N. parisii and other microsporidian genomes lack a key cell cycle inhibitor, which is 

encoded by a tumor suppressor gene found in humans. Anabolic metabolism and disregulated 

cell cycle are both features shared by many types of cancer cells. Thus, microsporidia may 

use cancer-like strategies of metabolic reprogramming together with a fast cell cycle to rapidly 

grow inside of host cells. 

Contact: mbakowski@ucsd.edu 

Lab: Troemel 

132 

Poster Topic: Pathogenesis


Identifying a genetic basis to resistance against microsporidian 

parasites 

Keir Balla 1 , Erik Andersen 2 , Zhi Yan 1 , Leonid Kruglyak 2 , Emily Troemel 1 

1 UCSD, La Jolla, CA, USA, 2 Lewis-Sigler Institute for Integrative Genomics, 

Princeton University, New Jersey, USA 

Microsporidia are intracellular eukaryotic parasites that infect nearly all animal phyla. As 

microsporidia can cause lethal disease in both humans and agriculturally important animals, 

it is critical that we learn more about the basis for host defense. We have recently identified 

a strong genetic component to C. elegans resistance against infection by the microsporidian 

pathogen Nematocida parisii. Strain ERTm1 is a natural pathogen that was first isolated 

from a wild-caught C. elegans near Paris, and since that time has been isolated from wildcaught 

nematodes in many parts of the world. N. parisii kills the N2 strain more quickly than 

the CB4856 strain. In addition, we have found that N. parisii is present at a higher pathogen 

load in N2 than in CB4856, and we have exploited this difference to pursue the responsible 

genetic locus. We developed a liquid culture infection assay and use quantitative PCR to detect 

pathogen RNA levels within the host. With this assay, we are analyzing a panel of recombinant 

inbred advanced intercross lines (RIAILs) generated by a cross between N2 and CB4856 for 

quantitative trait loci (QTL) mapping. We have measured pathogen load in over 100 RIAILs 

to map significant QTL on chromosomes II and V. RIAILs bearing CB4856 SNPs within these 

intervals were significantly associated with lower pathogen loads. We are now generating nearisogenic 

lines containing the QTL intervals in an otherwise entirely N2 or CB4856 background 

to confirm the role of these QTL in resistance and to allow for fine-mapping of the prospective 

quantitative trait nucleotides. The CB4856 resistance phenotype appears to be recessive to the 

N2 phenotype and thus we hypothesize it is conferred by a loss- or reduction-of-function allele 

in CB4856. We will test this hypothesis by performing RNAi experiments targeting candidate 

genes within the identified QTL in the N2 strain and performing phenotypic rescue experiments 

in the CB4856 strain. These experiments will provide the first insights about the genetic basis 

of resistance to microsporidia in any system. In addition to investigations on the host side of 

resistance, we have identified a new strain of N. parisii from a wild-caught C. briggsae from 

Kauai, Hawaii. We are comparing the relative virulence and the genome of this strain to the 

ERTm1 strain. Altogether, our studies will reveal insights into the co-evolutionary interactions 

that may be important for a variety of host-microsporidia pairs. 

Contact: kballa@ucsd.edu 

Lab: Troemel 

Poster Topic: Pathogenesis 

133


Mapping natural variation in sensitivity to the Orsay virus in C. 

elegans wild isolates 

Tony Belicard, Marie-Anne Felix 

Institut de Biologie de l?Ecole Normale Sup?rieure, CNRS-Inserm-ENS, Paris, 

France 

The first known virus naturally infecting C. elegans was recently discovered (Félix M-A, 

Ashe A, Piffaretti J, et al., 2011). The Orsay virus causes intestinal cell disorders to its natural 

host, the strain JU1580. Its genome is composed of two positive single-strand RNA segments 

and is close to that of known nodaviruses infecting fish and insects. Transmission is horizontal. 

The viral infection can be cured by submitting the embryos to bleach. Viral preparations can 

be obtained through 0.2 mm filtration. 

Here we explore inter- and intraspecific sensitivity to the virus in Caenorhabditis. We 

challenged strains of interest with a viral preparation and assayed replication of the virus 7 

days after infection. 

Until now there is no evidence that the Orsay virus can infect a C. briggsae culture. Two 

other related viruses (called Santeuil and Le Blanc viruses) have been found infecting wild 

isolates of C. briggsae and none of them seems able to infect C. elegans. Thus, each virus 

so far seems specific to C. elegans versus C. briggsae. 

At an intraspecific level, large variation in sensitivity to the Orsay virus is found among C. 

elegans wild isolates. We measured quantitatively, using RT-qPCR, the amount of RNA1 at 7 

days post-infection, in a set of 97 natural isolates of C. elegans. Using the RAD-sequencing 

data on these 97 strains (Andersen E, Gerke J, et al., 2012), we performed a Genome-Wide 

Association Mapping. We were able to detect a wide signal of 6 Mb in the center of Chromosome 

IV. This signal corresponds to a haplotype that is common to almost all sensitive strains and is 

found mostly in European isolates. We are now narrowing the region by screening for laboratory 

recombinations in this 6 Mb region and testing candidate genes in the region (see Jérémie Le 

Pen’s communication for complementary information). 

Contact: belicard@biologie.ens.fr 

Lab: Félix 

134 



The Human Herpesvirus Type 1 Latency Associated Transcript 

Produces Egg Laying and Locomotion Defects in the Nematode C. 

elegans 

Ana Bratanich, Jesica Diogo 

University of Buenos Aires,Buenos Aires,Argentina 

C elegans is presently utilized as a model for the study of pathogen virulence factors 

especially in the field of bacteriology and mycology. However, its application in virology has 

been essentially inexistent. In this work, we have utilized C elegans to obtain transgenic strains 

expressing a human herpes virus type 1 gene associated with the latency process in sensory 

neurons. The function of this gene (Latency Associated Transcript or LAT) has been extremely 

difficult to study in higher eukaryotic systems. In vivo and in vitro experiments would suggest 

that one of its roles is to modulate apoptosis. C elegans transgenic strains expressing the LAT 

gene showed important phenotypic changes in the form of locomotion and egg laying defects. 

Treatment with different drugs suggested that these phenotypes were produced by neuronal 

presynaptic defects. RNAi experiments proved these defects were specifically mediated by the 

LAT gene. No obvious anatomic changes were observed in the egg laying neuronal machinery 

when transgenic hermaphrodites were crossed with strains expressing GFP. However, a smaller 

number of apoptotic bodies was found in the gonads of LAT transgenic strains when compared 

to controls. To the authors’ knowledge, this is the first time that transgenic C elegans strains 

are obtained expressing a gene from a mammalian virus. 

Contact: abratanich@fvet.uba.ar 

Lab: Bratanich 


135


The Conserved 1-Cys Peroxiredoxin, PRDX-6, has Diverse Roles in 

Stress Resistance, Innate Immunity and Aging 

Emma Button, Elizabeth Veal 

Newcastle University, Newcastle-upon-Tyne, United Kingdom 

Peroxiredoxins (Prx) are highly conserved, abundant antioxidant enzymes that are important 

for longevity in yeast, worms, flies and mice. For instance, C. elegans, lacking the 2-cys Prx, 

PRDX-2, the human ortholog of the tumour suppressor Prdx1, age more rapidly and are shortlived 

[1]. Prx utilise reversibly oxidized cysteines in the catalytic degradation of peroxides but 

have other functions in signal transduction and as chaperones. For instance, mammalian 

1-Cys Prx are multifunctional enzymes with separate peroxidase and phospholipase A 2 (PLA 2) 

activities. 1-cys Prxs have been found to be important for oxidative stress resistance in mice and 

yeast and increased levels of human Prdx6 have been associated with lung and breast cancer 

[2]. The C. elegans genome encodes a single 1-cys Prx, PRDX-6, in which the PLA 2 active 

site residues are not conserved. Hence, we have used prdx-6 mutant C.elegans as a model 

to investigate the role of the peroxidase activity in stress resistance and aging. Surprisingly, 

we have made the discovery that C. elegans lacking prdx-6 are oxidative stress-resistant and 

long-lived at 15 o C. However, at 25 o C the lifespan of prdx-6 mutant and wildtype animals are 

indistinguishable. Our investigations into the basis for this temperature–dependent effect on 

aging have led us to discover that PRDX-6 plays pathogen-specific roles in innate immunity. 

Here, we will present the results of our investigations into the underlying mechanisms by which 

PRDX-6 influences stress resistance, aging and responses to different bacterial pathogens. 

1 Olahova M. et al Proc. Natl. Acad. Sci. USA 2008, 105:19839-44 

2 Fisher A.B. Antioxidants & Redox Signaling. 2011, 15:831-44 

Contact: Emma.Button@ncl.ac.uk 

Lab: Veal 

136 


Contact: cschen@mail.ncku.edu.tw 

Lab: Chen 


Shiga-like Toxin 1 Is Required Partly for The Pathogenicity of 

Escherichia coli O157:H7 in Caenorhabditis elegans 

Chang-Shi Chen1 , Ting-Chen Chou1 , Hao-Chieh Chiu2 , Cheng-Ju Kuo1 , Ching-Ming 

Wu3 , Wan-Jr Syu4 1Department of Biochemistry and Molecular Biology, National Cheng Kung 

University, Tainan, Taiwan, 2Department of Clinical Laboratory Sciences and 

Medical Biotechnology, National Taiwan University, Taipei, Taiwan, 3Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan, 

4Institute of Microbiology and Immunology, National Yang Ming University, Taipei, 

Taiwan 

Enterohaemorrhagic Escherichia coli (EHEC) causes life-threatening infections in humans 

as a consequence of the production of Shiga-like toxins. Lack of a good animal model system 

hinders the study of EHEC virulence with systematic genetic methods in vivo. Here we applied 

the genetic tractable animal model, Caenorhabditis elegans, as a surrogate host to study the 

virulence of EHEC as well as the host innate immunity to this human pathogen. Our results 

show that E. coli O157:H7, a serotype of EHEC, intoxicates, induces a severe bag of worms 

(Bag) phenotype, and kills C. elegans. Colonization and induction of the characteristic attaching 

and effacing (A/E) lesions by E. coli O157:H7 are concomitantly demonstrated in the intact 

intestinal epithelium of C. elegans in vivo. Genetic analysis indicates that the Shiga-like toxin 1 

(Stx1) of E. coli O157:H7 is a virulence factor in C. elegans and is required for full toxicity. The 

C. elegans p38 MAP kinase and the DAF-2 insulin-like signaling pathways, two evolutionally 

conserved innate immune signaling pathways, are activated and mediated in the regulation of 

host susceptibility to EHEC infection. Our results validate the EHEC-C. elegans interaction as 

suitable for future comprehensive genetic screens in both bacterial and host factors involved 

in the pathogenesis of EHEC infection. 


137


Leucobacter Strains Are Diverse Natural Pathogens of Caenorhabditis 

Laura Clark 1 , Marie-Anne Felix 2 , Maria Joao Gravato-Nobre 1 , Jonathan Hodgkin 1 

1 University of Oxford, Oxford, UK, 2 IBENS, Paris, France 

Examining wild isolates of Caenorhabditis is a productive way of discovering new nematode 

pathogens, some of which exhibit unusual modes of attack and reveal new aspects of host 

defense. Two cases, involving three bacterial strains belonging to the Gram-positive coryneform 

genus Leucobacter, provide illustration. First, the C. elegans isolate JU1088, obtained from 

an aviary in Kakegawa, Japan, was found to be chronically infected with a Leucobacter strain 

(CBX130/LJ) with similar effects to Microbacterium nematophilum, characterized by rectal 

colonization and inflammatory swelling of the tail region. The much-studied M. nematophilum 

has been repeatedly isolated as a lab contaminant but never found in the wild; strain LJ shows 

that rectal infection and host swelling response are part of the natural life of C. elegans. Infection 

by LJ exhibits some significant differences from infection by M. nematophilum. Second, an 

isolate of Caenorhabditis n. sp. 11, JU1635, found on rotting banana trunks in Cape Verde, 

was found to be doubly infected with two different Leucobacter strains, termed Verde1 and 

Verde2. The double infection could be transferred to C. elegans. Verde2 has similar but much 

more virulent effects to M. nematophilum and LJ: it rapidly kills most wildtype worms and elicits 

a strong but futile tail-swelling response. Most C. elegans Bus mutants (20+ complementation 

groups), which have been isolated for resistance to M. nematophilum, are also resistant 

to Verde2. Verde1 bacteria, in contrast, do not kill wildtype C. elegans but adhere densely 

over most of the nematode surface and elicit up-regulation of the defense peptide NLP-29. 

However, most Bus mutants (resistant to Verde2) are lethally hypersensitive to Verde1, dying 

from cuticle destruction, shrinkage and lysis. Verde1 therefore has latent potential as a virulent 

Caenorhabditis pathogen. A different kind of infection has been reported for Leucobacter strain 

TAN31504 (Muir & Tan, 2008, Appl Environ Microbiol 75:4185-98), which targets uterine tissue. 

A survey of other characterized Leucobacter species did not reveal further Caenorhabditis 

disease effects, but the properties of the four strains described above suggest that this genus 

may have a propensity to evolve anti-nematode pathogenicity. Progress on detailed description 

of the two Verde strains, and dissection of their virulence mechanisms, will be reported. 

Contact: lauracarolineclark@gmail.com 

Lab: Hodgkin 

138 



Discriminating Pathogens from Innocuous Microbes: C/EBP 

Surveillance Immunity in C. elegans Intestinal Defense 

Tiffany Dunbar, Zhi Yan, Keir Balla, Margery Smelkinson, Emily Troemel 

University of California San Diego, La Jolla, CA, USA 

Intestinal epithelial cells are regularly exposed to a wide variety of microbes, and must 

be able to rapidly distinguish between innocuous and harmful microbes in order to mount 

a specific response to dangerous microbes. P. aeruginosa is an opportunistic pathogen in 

humans and causes a lethal intestinal infection in C. elegans that requires some of the same 

virulence factors required for killing mammalian hosts. To investigate the early response to 

infection we defined a set of genes specifically induced by pathogenic P. aeruginosa. A GFP 

reporter for one of these genes, called irg-1 (infection response gene 1), is robustly induced 

by infection with pathogenic P. aeruginosa, but is not induced by other pathogens tested so 

far. Furthermore, irg-1 is not induced by non-pathogenic P. aeruginosa strains. Thus, the irg- 

1::GFP reporter provides a convenient and specific read-out for the early events in intestinal 

cell response to pathogenic P. aeruginosa. Induction of irg-1 is controlled by a basic leucine 

zipper (bZIP) transcription factor called zip-2 that is required specifically for irg-1 induction and 

provides defense against P. aeruginosa infection. 

We performed a full-genome RNAi screen to identify other factors in the zip-2/irg-1 pathway. 

From this screen we identified 57 RNAi clones that cause irg-1::GFP induction in the absence of 

infection. Many of these hits block mRNA translation, and we further confirmed that attenuation 

of translation triggers largely zip-2 dependent irg-1 induction. Surprisingly, we found that this 

attenuation of translation leads to activation of ZIP-2::GFP expression in the nuclei of intestinal 

cells. Our data indicates that regulation of ZIP-2 translation is conferred by a region in the 

zip-2 coding transcript that contains a conserved upstream open reading frame (uORF). We 

are currently investigating the mechanism by which this uORF mediates the response to P. 

aeruginosa infection. We also identified a candidate binding partner for ZIP-2, based on in 

vitro binding studies (Aaron Reinke and Amy Keating, personal communication) and RNAi 

knock-down in C. elegans. This binding partner is encoded by the C48E7.11 gene, which we 

have renamed cebp-2, since it is a likely ortholog of the C/EBP-gamma bZIP transcription 

factor in mammals. We are examining C/EBP signaling in mammals to determine whether the 

surveillance pathway used in C. elegans is also important in mammalian cells to discriminate 

pathogens from innocuous microbes. 

Contact: tldunbar@ucsd.edu 

Lab: Troemel 


139


The invertebrate lysozyme ILYS-3 aids bacterial disruption and acts 

in the intestine under non-autonomous pharyngeal control to protect 

against bacterial infection 

Maria Joao Gravato-Nobre , Jonathan Hodgkin 

University of Oxford, Oxford, UK 

Multiple immune effectors that fight pathogen infections have been identified in C. elegans: 

many act promptly taking just a few hours to reach peak levels and attain rapid microbial 

clearance. We hypothesize that there is a second group of effectors that “mop-up” pathogens 

that escape the initial response. We show that the C. elegans invertebrate lysozyme, ILYS-3 

functions in this way and is required for proper defense against pathogen infection. A full-genome 

microarray analysis previously identified a rapid up-regulation of ILYS-3 in response to M. 

nematophilum. Subsequent quantitative RT-PCR experiments revealed that ILY-3 levels peak 

at 72 h after challenge with different Gram-positive bacteria, including M. nem. and M. luteus. 

We find that ILYS-3 is critical for the survival of C. elegans exposed to Leucobacter Verde2, 

which evokes a swelling response in the rectum followed by almost 100% larval mortality 96 h 

after infection. Besides a hypersensitive response to Verde2, ilys-3 mutations permit increased 

intestinal proliferation of non-pathogenic E. coli strains, reflecting an impaired ability of larvae 

and young adults to reduce bacterial burden in the gut lumen. Conversely, over-expression 

of ILYS-3 confers striking protection against pathogen-mediated lethality by Verde2. ILYS-3 is 

most highly expressed in the pharynx and in the intestine of C. elegans. Intestinal induction 

of ilys-3p::GFP in response to infection by M. nematophilum requires activation of the ERK 

MAP kinase pathway. In the intestine of ERK mutants, basal expression of ilys-3p::GFP is 

reduced and its induction is abolished. Tissue specific experiments demonstrate that induction 

of ilys-3 is controlled in a cell-non-autonomous fashion. Expressing MPK-1 in the intestine of 

mpk-1 mutants did not restore ilys-3 expression or its induction upon exposure to M. nem. In 

contrast, the expression of MPK-1 in the pharyngeal muscle resulted in an increased constitutive 

expression of ilys-3p::GFP in the intestine and rescued reporter gene induction in the mpk-1 

(ku1) mutant upon infection. These findings indicate that activation of MPK-1 in the pharynx 

regulates intestinal expression of ILYS-3 and suggest a mechanism whereby pharyngeal cells 

sense danger signals and respond by activating an antimicrobial response in distal tissues, 

where pathogen clearance will be key to organismal survival. 

Contact: maria.gravato-nobre@bioch.ox.ac.uk 

Lab: Hodgkin 

140 



Dissecting ERAD Component Function in a Motor Neuron Disease 

Model 

Angela Jablonski, Robert Kalb 

University of Pennsylvania, Philadelphia, PA, USA 

Agingis a major risk factor for the development of neurodegenerative disease. Accumulation 

of aberrantly folded proteins is seen in neurodegenerative disease and these insoluble 

proteins may be toxic to neurons. Cellular processes that ensure correct protein folding may 

suppress toxicity and other age-related defects in neurodegeneration. One protein quality 

control mechanism is ER-associated degradation (ERAD). Improperly folded cell-surface or 

secreted proteins are retrotranslocated from the ER to the proteasome for ubiquitin-dependent 

degradation. ERAD dysfunction can lead to ER stress and, if unchecked, apoptosis. 

Several studies have linked dysfunction of ERAD to neurodegenerative diseases, including 

amyotrophiclateral sclerosis (ALS). ERAD has been studied extensively in yeast, but our 

understanding of this process is still limited. We had two goals: First, we wanted to determine 

if loss-of-function (LOF) alleles of individual ERAD components led to a phenotype (such as 

uncoordinated movement, sterility, or larval arrest). This would allow us to identify essential 

ERAD components versus components that were dispensable. Second, we wanted to determine 

if LOF alleles of individual ERAD components suppressed or enhanced proteotoxic insults 

incurred by expression of mutant TDP43 in the nervous system - C. elegans engineered to 

express a mutant version of TDP43 (M337V – implicated in familial ALS) display locomotor 

deficits and motor neuron death. To do this, we made double animals of mutant TDP43 and LOF 

ERAD component alleles, including ubxn-4 (tm3247), ufd-3 (tm2915), and cdc-48.1 (tm544). 

We found that ufd-3 (tm2915) improved average speed of animals by two-fold at L4+1d and 

L4+5d when compared to mutant TDP43 animals. Interestingly ufd-3 (tm2915) alone showed 

no difference to N2 on average locomotor speed at L4, L4+1d, L4+3d,L4+5d, or L4+7d. Ubxn-4 

(tm3247) enhanced toxicity and worsened average locomotor speed at stage L4. Meanwhile, 

the cdc-48.1 (tm544) double showed no change. These data support our hypothesis that some 

ERAD components are necessary, some may be dispensable, and others may be modifiers 

with the capability of suppressing or enhancing toxicity in models of motor neuron disease. 

Contact: ajablo@mail.med.upenn.edu 

Lab: Kalb 


141


A Transmembrane Leucine-Rich Repeat Protein Important for 

Microsporidia Infection in C. elegans 

Robert Luallen, Malina Bakowski, Emily Troemel 

University of California-San Diego, La Jolla, (CA), USA 

C. elegans has proven to be an excellent organism for the study of host/pathogen 

interactions and innate immunity. This is exemplified by the discovery of several signal 

transduction pathways used in host defense and recent discoveries showing that C. elegans 

surveils for disruption of core host cellular processes to detect infection. However, little is 

known about the earliest steps of C. elegans host/pathogen interactions. In particular, we do 

not know which host receptors are used to detect pathogens, nor which receptors may be 

exploited by pathogens to facilitate infection. To identify such receptors, we are studying a 

natural eukaryotic pathogen of C. elegans, a species of microsporidia called Nematocida parisii. 

N. parisii is an obligate intracellular pathogen that infects the intestine. Using larval arrest as 

an early readout for pathogen detection and infection, we conducted a targeted RNAi screen 

for genes that inhibited C. elegans arrest after N. parisii infection. One hit from this screen was 

a transmembrane (tm) protein containing an extracellular leucine-rich repeat (LRR) domain, 

which is found on numerous pathogen receptors from other systems, such as Toll-like receptors. 

Worms in which this LRR-tm gene was knocked down exhibited less arrest upon infection. 

We find that this defect in arrest is specific to N. parisii infection, because knockdown of this 

protein has no effect on arrest of worms infected with the bacterial pathogen Pseudomonas 

aeruginosa. We generated a tagged version of this protein and showed that it was expressed 

in the intestine, pharynx, and neurons of transgenic worms. Furthermore, it localized to the 

apical and vesicular membranes of the intestine, which poises this LRR protein for pathogen 

interaction in the intestinal lumen. Intestinal specific RNAi in the VP303 strain recapitulated 

inhibition of larval arrest after infection, suggesting this LRR-tm protein functions in the intestine 

to control a response to N. parisii. Knockdown of the LRR-tm protein resulted in slower N. parisii 

infection progression and lower pathogen load, as measured by FISH and qPCR. Together, 

the data suggests that this LRR protein may be involved early in C. elegans infection, either 

as a receptor used by N. parisii for efficient infection or as a suppressor of immunity. As this 

LRR-tm protein is conserved in mammals, dissecting its mechanism of action in early infection 

may inform us about intestinal microsporidia infection in humans. 

Contact: rluallen@ucsd.edu 

Lab: Troemel 

142 



The redox sensor TRX-1: a potential regulator of signaling in C. 

elegans 

Katie McCallum, Danielle Garsin 

The University of Texas Health Science Center at Houston, Houston, Texas, USA 

Our lab has previously demonstrated that in C. elegans intestinal infections stimulate 

the production of reactive oxygen species (ROS) by Ce-Duox1/BLI-3. Though overall this 

response has protective effects, it challenges intracellular redox homeostasis, resulting in 

the simultaneous up-regulation of intracellular detoxification enzymes. This response occurs 

through the activation of SKN-1, an oxidative stress response transcription factor, in a p38 

MAPK pathway dependent manner. It is currently unknown how BLI-3-generated ROS activates 

the p38 MAPK pathway. This question is of broad interest because ROS can serve as an 

important signaling molecule in not only the immune response, but in the regulation of other 

vital processes such as cell growth and differentiation. We propose that activation of the p38 

MAPK pathway is regulated by a thioredoxin sensor, which is sensitive to the ROS generated 

by BLI-3. In C. elegans, the role of thioredoxins is understudied. It has been demonstrated 

that a trx-1 null mutant exhibits decreased longevity on E. coli OP50. Classically, thioredoxin’s 

major role is thought to be as a cytosolic anti-oxidant, and therefore important for detoxifying 

reactive molecules. However, recent studies suggest that thioredoxins can also play a role in 

regulation by affecting the activity of signaling components. Our current hypothesis is that in the 

C. elegans intestine, thioredoxin, in conjunction with other factors, influences SKN-1 activation 

during infection. Specifically, we postulate that intracellular BLI-3 generated ROS is sensed 

by TRX-1 and relives repression of the p38 MAPKKK, NSY-1, ultimately allowing activation 

of SKN-1. In support of this hypothesis, preliminary data suggests that TRX-1 influences 

expression of SKN-1-regulated genes and susceptibility during infection. 

Contact: katie.c.mccallum@uth.tmc.edu 

Lab: Garsin 


143


Functional Characterization of Thioredoxin 3 (TRX-3), a 

Caenorhabditis elegans Intestine-Specific Thioredoxin 

Maria Jimenez-Hidalgo 1 , Cyril Leopold Kurz 2 , Jose Rafael Pedrajas 3 , Francisco Jose 

Naranjo-Galindo 1 , Juan Cabello 4 , Elamparithi Jayamani 5 , Eleftherios Mylonakis 5 , Juan 

Carlos Fierro-Gonzalez 6 , Peter Swoboda 6 , Antonio Miranda-Vizuete 1,7 

1 Centro Andaluz de Biologia del Desarrollo, Universidad Pablo de Olavide, Seville, 

Spain, 2 Centre d’Immunologie de Marseille-Luminy, Universite de la Mediterranee, 

Marseille, France, 3 Departamento de Biologia Experimental, Universidad de Jaen, 

Jaen, Spain, 4 Center for Biomedical Research of La Rioja (CIBIR), Logrono, Spain, 

5 Infectious Disease Division, Massachusetts General Hospital, Harvard Medical 

School, Boston, USA, 6 Center for Biosciences at NOVUM, Dept. of Biosciences 

and Nutrition, Karolinska Institute, Huddinge, Sweden, 7 Instituto de Biomedicina 

de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Seville, Spain 

Thioredoxins are a class of evolutionarily conserved proteins that have been demonstrated to 

play a key role in many cellular processes involving redox reactions. We report here the genetic and 

biochemical characterization of C. elegans TRX-3, the first metazoan thioredoxin with an intestinespecific 

expression pattern. By using GFP reporters we have found that trx-3 is expressed in the nucleus 

but also in the cytoplasm of intestinal cells where it shows a more prominent apical localization. trx-3 

(tm2820) loss of function mutants are viable, have normal longevity and progeny size and have no 

obvious phenotype other than a slightly smaller size. Despite the restricted expression in intestinal cells, 

trx-3 mutants do not show any defects in the gut during embryogenesis, accumulate normal levels of 

lipids, maintain a normal structural and functional integrity of the gut apical membrane and only exhibit 

a minor reduction in defecation cycle timing. The C. elegans intestine is constantly exposed to chemical 

stressors and toxins as well as pathogens and thioredoxins are well known antioxidant proteins, which 

have been shown to function as protective systems against different types of stresses. However, when 

subjected to different treatments that induce oxidative stress such as heat shock, acrylamide, juglone 

or paraquat exposure, trx-3 (tm2820) mutants did not display enhanced sensitivity. Furthermore, trx-3 

(tm2820) mutants did not modify the levels or subcellular localization of DAF-16, HSP-16.2 or GST- 

4 stress reporters. Interestingly, trx-3 is induced upon infection with Photorhabdus luminescens and 

Candida albicans but not other pathogens such as Serratia marcescens. Preliminary data show that 

trx-3 (tm2820) mutants are as resistant as wild type controls to P. luminescens killing but, in contrast, 

trx-3 overexpression protects against killing with this pathogen. We are currently evaluating the role 

of TRX-3 in Candida albicans infection. In this context, it has been shown that trx-3 is equally induced 

upon exposure to live or heat-killed Candida, thus suggesting that TRX-3 could function at early steps 

of infection, such as pathogen recognition or colonization. Together, our data indicate that TRX-3 

function in the intestine is dispensable for C. elegans development but might play an important role in 

the immune response elicited against some bacterial and fungal infections. 

Contact: amiranda-ibis@us.es 

Lab: Miranda-Vizuete 

144 


Contact: jmiskowski@uwlax.edu 

Lab: Miskowski 


Screening Potential Anthelmintic Compounds for Novel Activity 

Megan Gross1 , Olufadakemi Awoyinka1 , Michael Smith1 , M. Shahjahan Kabir2 , James 

Cook2 , Aaron Monte1 , Jennifer Miskowski1 1 2 University of Wisconsin-La Crosse; La Crosse, WI 54601, University of 

Wisconsin-Milwaukee; Milwaukee, WI USA 

Helminths are parasitic worms that infect plants, animals, and humans worldwide leading to a 

decreased food supply, economic hardship, and significant morbidity and mortality. Anthelmintics 

that combat these infections are represented by only six major classes of compounds. Misuse 

of these drugs has contributed to widespread anthelmintic resistance in livestock helminths 

and emerging drug resistance in human-infecting helminths. The identification of new lead 

compounds that target helminths is imperative. The non-parasitic nematode Caenorhabditis 

elegans has long been a model system for helminths - available anthelmintics kill C. elegans 

at doses similar to that of helminths, the molecular mechanism of action for all anthelmintics 

was elucidated using C. elegans, and the development of drug resistance has also been 

studied in C. elegans. 

Previously, we developed and performed two microassays to screen a unique collection of 

synthetic compounds for anthelmintic activity. These analogs were derived from an antimicrobial 

stilbene product originally isolated from Comptonia peregrina (“sweet fern”). The motility 

assay screened C. elegans for paralysis and the developmental assay screened worms 

for developmental arrest prior to sexual maturity, a decrease in fecundity, or lethality. Sixtyseven 

stilbenoid compounds were tested in one or both assays, and six test compounds were 

prioritized for further study. 

These test compounds possess a novel structure compared to existing anthelmintics, yet 

the potencies of the compounds do not warrant their development as bona fide anthelmintics 

at this time. Thus, we are utilizing these agents as probes to explore mechanisms by which 

worms might be targeted. To this end, the stilbenoids are being tested against mutant C. elegans 

strains that are resistant to existing anthelmintics using our two assays. This will reveal if any 

of the new compounds act via a novel molecular mechanism. We have initially focused on 

CL-5, which showed the strongest activity in both assays. To date, CL-5 has been tested on 

ivermectin-resistant strains, DA1302 and DA1306. Ivermectin is one of the most widely used 

anthelmintics on the market today, and ivermectin resistance has been documented in helminth 

strains. Interestingly, CL-5 affects ivermectin-resistant C. elegans in a dose-dependent manner, 

similar to wild-type worms. We are currently testing CL-5 against other anthelmintic-resistant 

C. elegans strains and will report our progress. 


145


Characterizing C. elegans behavior in response to E. faecalis 

Mona Gardner, Thomas Graciano, June Middleton, Edith Myers 

Fairleigh Dickinson University, College at Florham, Madison, NJ 

Caenorhabditis elegans feed on soil bacteria that may sometimes be pathogenic. We 

decided to develop a screen to determine the pathogenicity of environmentally-isolated strains 

of Enterococci. We assayed survival of C. elegans fed on various strains of E. faecalis. None 

of these strains had a significant effect on C. elegans survival. However, C.elegans behavior 

was altered in the presence of several strains. The behaviors observed included egg retention 

and avoidance of the E.faecalis lawns. While we know that in the total absence of food 

C.elegans leave their environment in search of food, and cease egg laying, their behavioral 

responses to Enterococcus (a potentially pathogenic food source) are not well characterized. 

Egg retention assays involved counting the number of eggs retained by adult worms cultured 

for several days on strains of E. faecalis. Worms exposed to some but not all strains showed 

an increase in egg retention. In avoidance assays, the number of worms occupying a lawn 

of E faecalis was counted periodically over 24 hours. Worms showed significant avoidance 

of all bacterial strains used. We have identified several strains of environmental Enterococci 

that altered C. elegans behavior and are now assaying those strains for antibiotic resistance, 

hemolysis, bacteriocin, and gelatinase production. We hope to correlate C. elegans behavioral 

responses to the expression of known virulence factors in E.faecalis strains. We also plan 

to investigate the molecular mechanisms by which E. faecalis affects behavior by assaying 

behavioral responses to bacteria in different genetic backgrounds. 

Contact: emyers@fdu.edu 

Lab: Myers 

146 



Exploring Antifungal Potential of CAMPs in the C.elegans Infection 

Model 

Massimiliano Olivi, Daniela Uccelletti, Maria Mangoni, Donatella Barra, Claudio 

Palleschi 

Sapienza, University of Rome, Italy 

The continuous development of multi drug resistant microorganisms, both bacterial and 

fungal, increased the interest in discovering new antimicrobial compounds. Using a wholeanimal 

model such as the nematode Caenorhabditis elegans for the screening of putative 

antimicrobial compounds will help studying not only the molecular mechanisms of microbial 

pathogenesis but also the toxicity of this molecules. 

In this study we focus our attention on the opportunistic human pathogen Candida 

albicans, whose infections have emerged as an important cause of morbidity and mortality 

in immunocompromised patients. It is well known that C. albicans, as well as other Candida 

species, are ingested by the nematode C. elegans and can establish a persistent lethal infection 

in the worm intestinal tract. Moreover, this model of pathogenesis replays key aspects of the 

fungus infections, such as iphae development, occurring in mammalian hosts. 

Naturally occurring membrane-active cationic antimicrobial peptides (CAMPs) serve as 

attractive candidates for the development of new therapeutic agents. Amphibian skin is one of 

the richest sources for such peptides whose in vivo activity against the opportunistic pathogen 

Pseudomonas aeruginosa has been demonstrated. We investigated the antifungal action in 

vivo of CAMPs from frog skin (e.g., temporins and esculentin fragments) on the ATCC10231 

strain of C. albicans utilizing Caenorhabditis elegans as minihost model. 

Contact: massimiliano.olivi@uniroma1.it 

Lab: Palleschi 


147


Using Bacterial Infection as a Tool to Dissect the Molecular 

Components of the Nematode Surface 

Delia O’Rourke, Rebecca Price, Dave Stroud, Jonathan Hodgkin 

University of Oxford, Oxford, UK. 

Previous forward genetic screens for worms resistant to the non-lethal bacterial infection by 

M. nematophilum identified 25+ bus genes that prevent infection, many of which are involved 

in the synthesis of the nematode surface. These mutants also show altered resistance and 

sensitivity to infections with two Gram-positive Leucobacter strains, Verde1 and Verde2, 

isolated from an infected worm found on the Cape Verde islands (J. Hodgkin and M. A. Felix 

unpublished). Verde1 infection, which is non-lethal to wild type worms, kills many of the bus 

mutants. This allowed us to conduct powerful suppressor screens to identify 4 subs (suppressors 

of bus sensitivity) of bus-2, bus-10, srf-2 and srf-5. The subs mutants show phenotypic features 

of altered surface coat including fragility and bleach sensitivity. 

Strikingly, subs-1 suppresses bus-10, srf-2 and srf-5 sensitivity to Verde1. Using whole 

genome sequencing we identified subs-1 (e3016) as an opal stop in exon3 of agmo-1 

(alkylglycerol monooxygenase) an enzyme that cleaves the O-alkyl bonds of ether lipids and is 

dependent on the co-factor tetrahydrobiopterin. Multiple alleles of subs-1 have been identified; 

three alleles include changes in the conserved residues of the fatty acid hydroxylase motif. I 

will describe the bus-10 suppressor screen and the identification of subs-1 and discuss how 

the molecular identification of these suppressors furthers our understanding of the surface 

coat of the worm. 

Contact: delia.orourke@bioch.ox.ac.uk 

Lab: Hodgkin 

148 



Identification of the Transcriptional Targets of the PMK-1 p38- 

Dependent Transcription Factor ATF-7 

Daniel Pagano, Dennis Kim 

MIT, Cambridge, MA, USA 

Innate immunity in C. elegans requires a conserved PMK-1 p38 mitogen-activated protein 

kinase (MAPK) pathway that regulates the basal and pathogen-induced expression of immune 

effectors. We identified ATF-7, a conserved basic-region leucine zipper (bZIP) transcription 

factor, as a downstream target of PMK-1 p38 MAPK and a regulator of immune effector gene 

expression. Unlike PMK-1 p38 MAPK, which is required for resistance against multiple stresses 

in addition to infection, ATF-7 appears to function specifically in the response to infection. 

Prior gene expression analyses of PMK-1 pathway mutants have identified putative immune 

effector genes; however, validating that these genes function in pathogen defense has been 

challenging due to the likely functional redundancy of immune effectors. The identification of 

ATF-7 and its prominent and specific role in PMK-1 p38-dependent immunity suggests that 

analysis of ATF-7 transcriptional targets will identify the genes that comprise the immune 

response. We performed RNA-Seq on RNA extracted from wild-type and atf-7 mutant animals 

fed non-pathogenic E. coli OP50 and pathogenic P. aeruginosa PA14 to determine the genes 

regulated by ATF-7 both basally and upon infection. We anticipate that the results of our wholegenome 

expression analysis will better define the immune response in C. elegans. 

Contact: dpagano@mit.edu 

Lab: Kim 


149


The Role of the G-protein Coupled Receptor FSHR-1 in the C. elegans 

Stress Response 

Amanda Miller, Hannah Anthony, Joseph Robinson, Shannon Hartley, Jennifer Powell 

Gettysburg College, Gettysburg, PA, USA 

Innate immunity is a critical defense mechanism against infection by pathogenic 

microorganisms that is present in virtually all metazoans. One of the major mediators of innate 

immunity in C. elegans is the conserved p38 MAPK pathway. This signaling pathway not only 

controls the expression of a set of putative antimicrobial effectors via the transcription factor 

ATF-7, but also coordinately regulates the response to oxidative stress via the transcription 

factor SKN-1 (Shivers, et al. PLoS Genetics 2010). FSHR-1 is a G-protein coupled receptor that 

is required in C. elegans for the defense against infection by diverse pathogens, including Gram 

negative bacteria, Gram positive bacteria, and fungi. This receptor is necessary and sufficient 

in the intestine for its immune function and has been shown genetically to act in parallel to the 

p38 MAPK pathway while converging on many of the same transcriptional targets. We are 

investigating whether FSHR-1 also plays a role in the response to various cellular stresses, 

including oxidative stress, thermal stress, and heavy metal stress. Preliminary results suggest 

that, like p38 MAPK, FSHR-1 is important for the response to oxidative stress. 

Contact: jpowell@gettysburg.edu 

Lab: Powell 

150 


Contact: amirsa@caltech.edu 

Lab: Sternberg 


Nematodes Living in Anoxic Conditions at a Deep-sea Methane Seep 

are Infected With Sexually Transmitted Parasitic Fungus-related 

Microsporidia 

Amir Sapir1 , Adler Dillman1 , Manuel Mundo-Ocampo2,3 , James Baldwin2 , Victoria 

Orphan4 , Paul Sternberg1 1Howard Hughes Medical Institute and Division of Biology, California Institute of 

Technology, Pasadena, CA 91125, USA, 2Department of Nematology, University 

of California, Riverside, CA 92521, USA, 3CIIDIR-IPN, Unidad Sinaloa, Guasave, 

Sin. Mex C.P. 81000, 4Division of Geological and Planetary Sciences, California 

Institute of Technology, Pasadena, CA 91125, USA 

Intracellular parasites of the phylum Microsporidia infect and thrive on large range of hosts 

including nematodes from the elegans group such as C. elegans. Microsporidia biodiversity, 

host specificity, and infection modes in the context of their natural environment are poorly 

understood but are of growing medical and agricultural interests due to the proposed roles 

of microsporidia infection in AIDS patients mortality and colony collapse disorder of infected 

honey bees. In a survey aimed to identify and characterize deep sea nematodes along with 

their symbiotic microbes in methane cold seeps, we surprisingly discovered a new marine 

nematode species that is infected with microsporidia. The infected worms were found primarily 

as male and female adults that consume methane and sulfide-oxidizing microorganisms in 

an anoxic, chemosynthetic niche. Microsporidia infection was strictly species-specific but 

found in samples taken from the same site in the Pacific (Hydrate Ridge) in two successive 

years demonstrating an ecologically stable interaction between microsporidia and deep sea 

nematodes. Microsporidia spores and intracellular meronts localization in the reproductive 

systems of both infected males and females nematodes suggests that the fungus is transmitted 

sexually in contrast to most microsporidia species, which are known to be transmitted by oralfaucal 

cycles. Detailed morphological analysis of infected tissues by transmission electron 

microscopy revealed that the fungus targets cells of the body wall muscles causing muscle 

malformation and fiber rearrangements. An 18S rRNA-based phylogeny suggests there 

were two independent events of microsporidia-nematode parasitism. Additionally, infection of 

deep sea worms may represent the first host-switch outside the basal bryozoan hosts during 

microsporidia evolution. The discovery of a parasitic fungus that thrives on a marine nematode 

host is the first reported case of deep sea microsporidia highlighting the potential for additional 

as yet uncharacterized species of Microsporidia and other parasitic fungi living in anoxic, deep 

sea environments. 


151


Key Residues of Cry5B Structure and Function: Mutagenesis by 

Alanine Scanning 

Jillian Sesar, Yan Hu, Sandy Chang, Arash Safavi, Raffi Aroian 

University of California, San Diego, San Diego, CA, USA 

Soil-transmitted helminthes (hookworms, whipworms, and Ascaris) infect more than 2 

billion people worldwide. Only one drug (albendazole) is able to show a high enough efficacy 

against parasite worms under conditions for mass drug administration. However, recent studies 

have shown an increase in resistance to this drug, stressing the importance of finding a new 

treatment option. Crystal (Cry) proteins produced from the soil bacterium Bacillus thuringiensis 

have been used for decades as a means to control insects that destroy crops and transmit 

human diseases, and studies have shown these proteins to be safe to humans. Our lab has 

shown that crystal proteins, specifically Cry5B, are able to kill both the free-living nematode 

Caenorhabditis elegans, as well as parasitic roundworms (eg. Ancylostoma ceylanicum, 

hookworm). We are currently investigating several of these crystal proteins to be safe and 

effective anthelmintics. 

Cry proteins intoxicate invertebrates by acting as pore-forming toxins. Several defined 

steps in their mechanism of action have been suggested from insect studies, but there is still 

great uncertainty as to the importance of these various steps. We believe that the C. elegans 

– Cry5B system has great potential to unlock mysteries surrounding Cry proteins. 

Here, I have mutated all of the 698 amino acids in the toxin domain of Cry5B, and 

subsequently tested these mutants on C. elegans to assess for changes in toxicity levels. 

These results display either an increase or decrease in toxicity as compared to the wild type 

Cry5B. This information has two main applications. First, it can tell us which residues are 

important in Cry5B protein function, with the eventual goal being to correlate these changes 

in activity with specific changes in protein functionality (eg. receptor binding, pore formation). 

Second, we can use the information gathered from the screen against C. elegans to identify 

Cry protein mutants that could have potential increases in toxicity against the parasites. Our 

goal here would be to ultimately identify improved Cry protein variant candidates for treating 

one of the most neglected diseases of our time, parasitic worms. 

Contact: jsesar@ucsd.edu 

Lab: Aroian 

152 



Caenorhabditis elegans Neutralizes Small Molecule Toxins Produced 

by Pseudomonas aeruginosa 

Gregory Stupp, Ramadan Ajredini, Arthur Edison 

University of Florida, Gainesville, Fl, USA 

Caenorhabditis elegans, which is found in soil and decaying fruit, is exposed throughout its 

life to a variety of pathogenic microbes, which makes it an ideal candidate to study bacterial 

resistance. Although C. elegans has a well-developed innate immune system, it still remains 

susceptible to many pathogens, including many that affect humans, such as Pseudomonas 

aeruginosa, a common pathogen of both plants and animals. P. aeruginosa possesses a 

variety of virulence factors, including toxic phenazine compounds such as pyocyanin and 

1-hydroxyphenazine (1-HP) which are often found in lungs of P. aeruginosa-infected cystic 

fibrosis patients. These redox-active compounds are thought to cause damage to cells by 

producing reactive oxygen species and disrupting normal redox reactions. 

P. aeruginosa grown on high-osmolarity media is able to kill L4 stage C. elegans in as 

little as 6 hours through the production of phenazines such as phenazine-1-carboxylic acid 

(PCA), 1-HP, and pyocyanin. We have found that upon exposure to 1-HP, the worms modify 

the compound into at least 5 metabolites. These metabolites, all glycosides of 1-HP, are found 

in differing concentrations and forms in the worm media and in worm bodies. All of these 

glycosides of 1-HP are less toxic to the worm than 1-HP itself, suggesting that C. elegans is 

actively detoxifying its environment. We have identified several of the major components of 

the worm media and homogenized worm pellet of young adult C. elegans exposed to 1-HP. 

The worm media contains 1-(β-glucopyranose)-phenazine (mono), 1-(6-β-glucopyranoseβ-glucopyranose)-phenazine 

(di), and at least two phenazine-trisaccharides (tri), while the 

homogenized worm pellet contains 1-(3-phospho-glucopyranose)-phenazine (G3P) along with 

the mono, di, and tri. We have shown that at concentrations of 200 μM, 1-HP kills ~80% of L4s 

after 6 hours, while mono, di, tri, and G3P all kill less than 5%. We are currently investigating 

the concentration and time-dependence of 1-HP exposure on glucoside production and are 

screening other species for this detoxification activity. 

Contact: stuppie@ufl.edu 

Lab: Edison 


153


Coprinopsis cinerea Lectins-mediated Toxicity against C. elegans 

Katrin Stutz 3 , Alex Butschi 3 , Silvia Bleuler-Martinez 1 , Mario Schubert 2 , Markus Aebi 1 , 

Markus Kuenzler 1 , Michael Hengartner 3 

1 Institute of Microbiology, ETH Zurich, Switzerland, 2 Institute of Molecular Biology 

and Biophysics, ETH Zurich, Switzerland, 3 Institute of Molecular Life Sciences, 

University of Zurich, Switzerland 

Lectins are non-immunoglobulin, carbohydrate-binding proteins without catalytic activity 

towards the recognized carbohydrate. They are widely distributed among eukaryotes such 

as plants, fungi and mammals as well as among prokaryotes. Several lectins of Coprinopsis 

cinerea and of other fungi display toxicity towards Caenorhabditis elegans and other organisms 

such as Aedes aegypti, Acanthamoeba castellanii and HeLa cells. Thus, they may be part of 

a lectin-mediated defense system of higher fungi against predators and parasites. 

Our goal is to unravel the glycotargets that are bound by the C. cinerea lectins CGL2 and 

CCL2 in C. elegans as well as the underlying toxicity mechanisms. The results may reveal an 

Achilles heel in this organism and might pave the way to new approaches in fighting animal 

parasitic nematodes. 

Toxicity of lectins against C. elegans is assessed by feeding E. coli that overexpress lectins. 

This results in inhibition of development and reproduction and eventually leads to premature 

death. As a proof of principle, we could show for the galectin CGL2 that its toxicity depends 

on its ability to bind to a galactose-containing glycoconjugate present on the apical surface 

of the intestinal lumen. We used Mos1-transposon mutagenesis to isolate mutants resistant 

to CGL2. The molecular analysis of the resistance genes allowed us to predict the structure 

of the glycoepitope bound by CGL2, and also revealed a novel, evolutionary conserved 

glycosyltransferase (GALT-1). 

Interestingly, toxicity assays of a second C. cinerea lectin, CCL2, showed toxicity exclusively 

towards C. elegans and Drosophila melanogaster; unlike CGL2 that is toxic to a broad range 

of species. Glycan array analysis of recombinant CCL2 revealed a pronounced carbohydratespecificity 

for Fucα1,3GlcNAc-containing glycans. Resistance of C. elegans mutants (bre-1, 

ger-1, fut-1) defective in the biosynthesis of the α1,3-core fucoside confirmed this glycoepitope. 

Feeding C. elegans with a dTomato::CCL2 fusion protein showed that CCL2 binds, like CGL2, 

to the surface of the intestinal epithelium. 

By EMS mutagenesis and RNAi screens as well as biochemical purification of the 

glycotarget, we want to learn more about the structure of the CCL2 target. In addition, we 

will perform transmission electron microscopy and metabolomics to further elucidate toxicity 

mechanisms. 

Contact: bluekeye@gmx.net 

Lab: Hengartner 

154 



Understanding the Molecular Underpinnings of Pathogen Recognition 

in C. elegans 

Kwame Twumasi-Boateng, Hae-Sung Kang, Michael Shapira 

University of California, Berkeley, Berkeley,CA,USA 

Caenorhabditis elegans has been used for over a decade to characterize signal transduction 

pathways involved in innate immunity. However, the identity of the signals responsible for 

initiating immune responses are not clear. While the distinct C.elegans immune response to 

different pathogens suggests specific recognition, the molecular basis for this remains unknown. 

To better understand what initiates the immune response, we took advantage of natural variation 

in colonization of the C.elegans intestine following exposure to Pseudomonas aeruginosa. 

Genome-wide analysis of gene expression in worms that were non-colonized versus those that 

were fully-colonized revealed that non-colonized worms displayed an immune response which 

was at least as robust as their colonized counterparts, indicating that the immune response 

preceded substantial colonization-associated damage. Further analyses using quantitative 

RT-PCRshowed that pathogen-secreted factors were not sufficient to induce immune gene 

expression, but an intact non-pathogenic Pseudomonas species was. This suggests recognition 

of Pseudomonas-specific structural components. Further analysis is underway, using transgenic 

worms expressing GFP from the promoter of an early infection-response gene (induced within 

one hour of exposure to Pseudomonas),to study the molecular underpinnings of this response. 

Finally, results will be presented from the preliminary characterization of a gene family encoding 

a protein domain that in plants is involved in microbial envelope recognition, and its roles in 

worm immune responses and protection. 

Contact: kwametb@berkeley.edu 

Lab: Shapira 


155


Reactive oxygen species generated by BLI-3/Ce-Duox1 during 

infection triggers the activation of SKN-1 in C. elegans 

Ransome van der Hoeven, Katie McCallum, Melissa Cruz, Danielle Garsin 

University of Texas, Health Science Center - Houston, Texas, USA 

Coordinated regulation of immune reactions is not only crucial to fight invading pathogens, 

but also vital in preventing injury to host tissue. Uncontrolled immune responses can lead to 

damage, sepsis and ultimately death of the host. An example of an immune response that can 

potentially harm host tissue is the purposeful generation of reactive oxygen species (ROS) 

by NADPH oxidase family of proteins. Recent studies using C. elegans and mammalian cell 

lines have shown that intestinal mucosal cells are involved in innate immunity through several 

mechanisms, one being the production of ROS by dual oxidases (Duox) as an antimicrobial. 

However the mechanisms by which the mucosal cells maintain homeostasis during infection are 

relatively unknown. Using C. elegans as a model system, we tested the hypothesis that ROS 

produced by intestinal cells in response to infection activates the oxidative stress transcription 

factor SKN-1, which is an ortholog of the mammalian Nrf transcription factor. Following oxidative 

stress, SKN-1 promotes survival by upregulating genes involved in the detoxification of ROS 

and other xenobiotic compounds. We demonstrate that SKN-1 is activated in the intestine of 

the worm when infected with the human pathogens Enterococcus faecalis and Pseudomonas 

aeruginosa. Furthermore, we show several SKN-1 dependent genes gcs-1, gst-4, gst-5, gst-7 

and gst-10 are upregulated during infection. More importantly we establish that ROS produced 

by Ce-Duox1/BLI-3 activates SKN-1 through the p38 MAPK signaling pathway. Systematic 

analysis of the p38 MAPK pathway revealed that components NSY-1, SEK-1 and PMK-1 are 

required for activation of SKN-1. Loss of skn-1 decreased resistance to the pathogens, whereas 

overexpression of SKN-1 resulted in enhanced survival, suggesting a protective role for SKN- 

1 during infection. Overall, SKN-1 is activated by the p38 MAPK signaling axis in response 

to ROS generated by Ce-Duox1 during infection in the intestinal lining of C. elegans. The 

aim of the current study is to elucidate the regulation of Ce-Duox1 in response to pathogenic 

bacteria. Using RNA-mediated interference (RNAi) we have identified several components of 

signal transduction cascades that are involved in the regulation of BLI-3/Ce-Duox1 activity in 

response to E. faecalis. 

Contact: ransome.vanderhoeven@uth.tmc.edu 

Lab: Garsin 

156 



TRPM Channels are Required for Clozapine’s Effects in C. elegans 

Xin Wang, Taixiang Saur, Bruce Cohen, Edgar(Ned) Buttner 

McLean Hospital & Harvard Medical School, Belmont MA 

Clozapine is the most effective drug for refractory schizophrenia, but its widespread use 

has been limited due to severe adverse effects, like agranulocytosis, seizures, tachycardia, 

and weight gain. The mechanisms of clozapine’s therapeutic and side effects remain unknown. 

Clozapine can cause larval arrest and lethality in C. elegans. We took advantage of these 

phenotypes by performing a genome-wide feeding RNAi screen for suppressors of clozapineinduced 

larval arrest (Scla). The screen yielded 42 suppressors, one of which is gtl-2. GTL-2 

is orthologous to the human transient receptor potential cation channel subfamily M member 3 

with 38% sequence identity. We validated the RNAi result by confirming the Scla phenotype in 

a partial loss-of-function strain, gtl-2(n2618). The Scla phenotype was not observed in two other 

TRPM loss-of-function mutants, namely gtl-1(ok375) and gon-2(q362). However, gtl-1(ok375), 

gon-2(q362), gtl-1(dx171);gtl-2(tm1463) and gon-2(q388);gtl-2(tm1463) suppress clozapineinduced 

lethality, while gtl-2 mutants do not. GTL-2 is expressed in the pharynx and excretory 

cell and regulates magnesium levels in C. elegans. GTL-1 and GON-2 also regulate Mg 2+ levels 

by taking up Mg 2+ in the intestinal cells. Inactivation of GTL-2 causes hypermagnesemia[1], 

and gtl-1;gon-2 and gtl-1;gtl-2 double mutants show hypomagnesemia[2]. Suppression of 

clozapine-induced lethality in gtl-1 and gon-2 animals could be due to hypomagnesemia. 

1. Teramoto T, et al,. PLoS One, 2010. 5(3): p. e9589. 

2. Teramoto T, et al,. Cell Metab, 2005 1(5): p. 343-54. 

Contact: xwang@mclean.harvard.edu 

Lab: Buttner 


157


QTL Mapping of Differential Susceptibility to Bacteria in 


Ziyi Wang 1 , Michael Herman 1 , Basten Snoek 2 , Jan Kammenga 2 

1 Kansas State University, Manhattan (KS), USA, 2 Wageningen University, 

Wageningen, The Netherlands 

C. elegans is a free-living nematode that naturally consume bacteria as food source. 

However, they face a challenge in that some dietary bacteria could also be pathogenic. The 

bacterial environments C. elegans naturally encounter are unlikely to be homogeneous; in 

addition, no evidence suggests the animals can selectively ingest certain bacteria from the 

environment. Therefore, as the animals feed on heterogeneous food sources, they have to 

simultaneously defend against the potential pathogens. Escherichia coli OP50, for example, the 

standard laboratory food for C. elegans, is generally considered as non-pathogenic. However, 

a natural isolate of the bacterium Stenotrophomonas maltophilia JCMS was surprisingly 

pathogenic to C. elegans. S. maltophilia is a ubiquitous bacterium that can cause nosocomial 

infections, especially in immune-compromised individuals, and has been suggested to be 

an emerging human pathogen. We scored adult survivorship of two C. elegans isolates, N2 

(Bristol, England) and CB4856 (Hawaii), exposed to E. coli OP50 or S. maltophilia JCMS, 

as an indirect measurement of pathogenicity of the bacteria. The results demonstrated adult 

survivorship in different bacterial environment is a complex trait that is determined by both 

genetic and environmental factors, as well as genotype by environment (GxE) interactions. 

In order to identify the underlying genetic basis, we mapped quantitative trait loci (QTL) in a 

N2xCB4856 recombinant inbred panel for differential susceptibility between E. coli OP50 and S. 

maltophilia JCMS. We have identified two QTL, one on LGI and the other on LGX. Focusing on 

the LGX QTL first, we used introgression lines (ILs) that contain distinct lengths of chromosome 

X from CB4856 in an otherwise N2 genomic background to confirm the position of this QTL. 

We have detected a robust GxE effect in one IL that carries an introgression overlapped with 

LGX QTL. Our results clearly show a genetic basis for variation in C. elegans susceptibility to 

bacteria. However, further investigation is needed to dissect both QTL and pinpoint the causal 

loci or the genes. 

Contact: ziyiwang@ksu.edu 

Lab: Herman 

158 


Contact: jordan.ward@ucsf.edu 

Lab: Yamamoto 


C. elegans Acyl-CoA synthetase-3 And The Nuclear Receptor NHR-25 

Promote Epidermal Integrity And Resistance To Pathogens. 

Jordan Ward2 , Carole Couillault1 , Brendan Mullaney2 , Teresita Bernal2 , Marc Van Gilst3 , 

Kaveh Ashrafi2 , Jonathan Ewbank1 , Keith Yamamoto2 1 2 3 CIML, Marseilles, France, University of California, San Francisco, USA, Fred 

Hutchinson Cancer Research Center, Seattle, USA 

We have previously demonstrated that the acyl-CoA synthetase, acs-3, regulates the 

nuclear hormone receptor, nhr-25, to promote an endocrine program of lipid uptake and 

synthesis(1). Given that NHR-25 is a transcription factor, we performed microarray analysis to 

identify regulated genes promoting this metabolic program. Much to our surprise, despite the 

antagonistic genetic relationship between acs-3 and nhr-25, there were virtually no differentially 

regulated genes discovered by the microarrays. Rather, loss of either acs-3 or nhr-25 activity 

leads to very similar transcriptional profiles following EASE and DAVID analysis, with significant 

upregulation of genes involved in cuticle formation and pathogen response. Elevated pathogen 

response gene expression can be caused by osmotic stress resistance phenotypes and 

cuticular damage. acs-3 mutants have: i) a subtle resistance to acute hyperosmotic stress; 

ii) a partially penetrant sensitivity to hypo-osmotic stress; and iii) a severe cuticular barrier 

defect, as exhibited by elevated staining with the cuticle impermeable Hoechst 33358 dye in 

tail nuclei. nhr-25 mutants showed essentially wild-type responses in all of these assays. We 

then performed sensitivity assays to the pathogens Drechmeria coniospora and Pseudomonas 

aeruginosa to test whether the compromised epidermal barrier affects resistance to pathogens. 

Loss of acs-3 activity causes hypersensitivity to Drechmeria, while nhr-25 mutants are sensitive 

to Pseudomonas. Intriguingly, acs-3 mutation suppresses the sensitivity of nhr-25 mutants to 

Pseudomonas. Together, these results highlight a link between the ACS-3-NHR-25 endocrine 

program, the cuticle barrier and resistance to pathogens. 

1. B. C. Mullaney et al., Regulation of C. elegans fat uptake and storage by acyl-CoA synthase-3 is dependent 

on NR5A family nuclear hormone receptor nhr-25, Cell Metab 12, 398–410 (2010). 


159


Genetic Mechanisms of Innate Immune Response: The interaction 

between Caenorhabditis elegans and the opportunistic pathogen 

Stenotrophomonas maltophilia 

Corin White1 , Vinod Mony1 , Brian Darby2 , Michael Herman 1 

1 2 Kansas State University, Manhattan, KS, USA, University of North Dakota, Grand 

Forks, ND, USA 

Stenotrophomonas maltophilia is a ubiquitous aerobic gram-negative bacterium that can 

cause nosocomial and community-acquired infections. S. maltophilia isolates, including clinical 

K279a, have been shown to have nematocidal activities. In the course of our studies, we 

discovered a pathogenic interaction between Caenorhabditis elegans and a local S. maltophilia 

environmental isolate,JCMS. S. maltophilia strains reduce C. elegans lifespan, which is used 

as an indicator of bacterial pathogenesis. Based on several analyses, we find JCMS to be 

more virulent than the reference environmental isolate R551-3 and clinical isolate K279a. In 

addition, liveJCMS accumulates in the intestine significantly more than the standard laboratory 

C. elegans food source E. coli OP50. We have also found that both heat and UV-killed JCMS 

kills C. elegans less effectively than live bacteria, suggesting that the accumulation of living 

bacteria contributes significantly to JCMS virulence. Several innate immune pathways that 

serve to protect C. elegans from various pathogenic bacteria have been discovered, including 

the p38 MAP kinase and Sma/MabTGFβ-related pathways. Mutants that disrupt numerous 

components of these pathways are hypersensitive to both JCMS and OP50, suggesting that 

the functions of these genes are conserved in non-specific bacterial response. Surprisingly, 

ins-7/insulin-like ligand or daf-2/insulin receptor mutants displayed shortened lifespans on S. 

maltophilia JCMS. This observation is striking as daf-2 mutants are long lived on most other 

bacterial pathogens. We are currently using a forward genetic approach to identify candidate 

genes that may explain this S. maltophilia JCMS specific evasion of the DAF-2/16 pathway. 

Over 1350 ethyl methane sulfonate (EMS) induced mutant lines have been screened for hypersusceptibility 

or resistance to JCMS and we have identified both types of mutants. Future work 

includes the confirmation of these phenotypes and subsequent fine gene mapping. In addition 

to further understanding the interaction of C. eleganswith a novel pathogen, S. maltophilia, 

our studies might also provide insight on the mechanisms of adaptation C. elegans employs 

for diverse bacterial environments. 

Contact: cwhite21@k-state.edu 

Lab: Herman 

160 



Characterization of the Effects of Naturally Isolated Salmonella 

enterica Strains on Caenorhabditis elegans 

Amanda Wollenberg 1 , Anna Maria Alves 1 , Michael McClelland 2 , Javier Irazoqui 1 

1 Massachusetts General Hospital, Boston, (MA), USA, 2 San Diego Institute of 

Biological Research, San Diego, (CA), USA 

Salmonella enterica is a gastrointestinal pathogen that is responsible for both many cases 

of food-borne illness and enteric (typhoid) fever. We are studying the immune response of C. 

elegans to a range of Salmonella subspecies and serovars. In particular, we are studying a 

set of 66 isolates whose genomes have been fully sequenced. These isolates include many 

serovars within the well-studied S. enterica subspecies I, whose members are often specialized 

for vertebrate hosts (e.g. paratyphi), but the set also includes strains from the other five S. 

enterica subspecies. Here, we present our preliminary analysis of pathogenicity and persistence 

in the C. elegans model and discuss directions for future research. 

Contact: acwollenberg@gmail.com 

Lab: Irazoqui 


161


Analysis Of mi-RNAS, Target Prediction Algorithms And Databases In 

C.elegans 

Hema Kasisomayajula, Frnklyn Bolander 

University of South Carolina 

Current methods for target prediction for mi-RNA in C.elegans include complementarity, 

thermodynamic approaches and support vector based methods. 

The most valid evidence comes from wetlab procedures, but the information from the 

conservation of target sequence is not used in current method. 

This study hopes to address the need for a new database that takes all the evidence into 

account and pairs information from in-silico predictions with literature mining matches that use 

experimental evidence into account, to rate confidence levels in prediction. 

Contact: HEMA090A@gmail.COM 

Lab: Bolander 

162 

Poster Topic: Small RNAs


C. elegans rrf-1 Mutations Maintain RNAi Efficiency in the Soma in 

Addition to the Germline 

Caroline Kumsta, Malene Hansen 

Sanford-Burnham Medical Research Institute, La Jolla, CA, USA 

Gene inactivation through RNA interference (RNAi) has proven to be a valuable tool for 

studying gene function in C. elegans. When combined with tissue-specific gene inactivation 

methods RNAi has the potential to shed light on the function of a gene in distinct tissues. In this 

study we characterized C. elegans rrf-1 mutants to determine their ability to process RNAi in 

various tissues. These mutants have been widely used in RNAi studies to assess the function 

of genes specifically in the C. elegans germline. 

Upon closer analysis we found that two rrf-1 mutants carrying different loss-of-function alleles 

were capable of processing RNAi targeting several somatically expressed genes. Specifically, 

we observed that the intestine was able to process RNAi triggers efficiently, whereas cells in 

the hypodermis showed partial susceptibility to RNAi in rrf-1 mutants. Other somatic tissues 

in rrf-1 mutants, such as the muscles and the somatic gonad, appeared resistant to RNAi. 

In addition to these observations, we found that the rrf-1 mutation induced the expression of 

several transgenic arrays, including the FOXO transcription factor DAF-16. Unexpectedly, rrf-1 

mutants showed increased endogenous expression of the DAF-16 target gene sod-3; however, 

the lifespan and thermo-tolerance of rrf-1 mutants were similar to those of wild-type animals. 

In sum, our data show that rrf-1 mutants display several phenotypes not previously 

appreciated, including broader tissue-specific RNAi-processing capabilities, and our results 

underscore the need for careful characterization of tissue-specific RNAi tools. 

Contact: ckumsta@sbmri.org 

Lab: Hansen 


163


Genetic requirements for viRNAs-mediated antiviral immunity in C. 

elegans 

Jeremie Le Pen, Alyson Ashe, Leonard Goldstein, Eric Miska 

Gurdon Institute, University of Cambridge, Cambridge, United Kingdom 

The Orsay virus is a natural pathogen of C. elegans (Felix M-A, Ashe A, Piffaretti J, et 

al., 2011). It can enter and replicate in the nematode’s intestinal cells in normal solid culture 

conditions, and it exhibits horizontal transmission only. This virus, which contains two positive 

single-strand RNA molecules, is distantly related to viruses in the family Nodaviridae. It provides 

a unique material to study antiviral immunity in C. elegans. 

The virus-derived small interfering RNAs (viRNAs) play a key role in the resistance to the 

Orsay virus in the N2 C. elegans strain. However, the strain JU1580, which is a natural host of 

the Orsay virus, fails to produce a robust viRNA response. This correlates with an increased 

sensitivity to the virus of the strain JU1580, when compared to N2. We are currently using 

the Orsay virus to investigate the genetic requirements for viRNA-mediated immunity using 

a quantitative trait locus (QTL) approach as well as a candidate gene approach (also see the 

abstract from our collaborators, Tony Belicard & Marie-Anne Felix, who measured the viral 

sensitivity of 97 natural isolates of C. elegans). We aim to enhance the anti-viral immunity of 

JU1580 animals by rescuing key components of the viRNAs pathway. 

Moreover, recent findings using a transgene of the Flock House virus, a fly pathogen, 

integrated in the C. elegans genome suggested that viRNAs can be transmitted across 

generations in a template-independent manner, leading to a form of transgenerational 

vaccination (Rechavi O, Minevich G, Hobert O, 2011). We are using the Orsay virus as a model 

to question the possibility of an inheritance of viRNAs in nature. 

Contact: jl572@cam.ac.uk 

Lab: Miska 

164 



Unifying Models of Biological Timers: A Molting Cycle Approach 

Gabriela Monsalve, Alison Frand 

University of California-Los Angeles, Los Angeles, CA, USA 

The temporal coordination of reiterative and sequential processes is critical for animal 

development. The heterochronic gene network programs the successive temporal fates of 

epithelial stem cells (seam cells). These cells undergo asymmetric divisions early in every 

larval stage, and yet contribute to the synthesis of new cuticles late in every larval stage, 

as part of the molting cycle. Relatively little is known about the mechanisms that link the respecification 

of seam cell fates with the four molts characteristic of C. elegans development. 

We recently reported that cyclical and stage-specific actions of LIN-42/PERIOD coordinate the 

temporal re-specification of epidermal stem cells and related cell divisions with rapid molts. 

Using bioinformatic approaches, we have uncovered additional evidence that interconnected 

regulatory interactions among LIN-42, the conserved nuclear hormone receptors NHR-23 

and NHR-25, and the let-7 family of microRNAs together compose a novel developmental 

oscillator that drives larval molting cycles. This timer likely couples the periodic molts with 

progressive development of the epidermis, as both lin-42 and let-7 also function in the 

heterochronic network to program the quality of sequential life stages and the expression of 

additional stage-specific heterochronic genes. The discovery that LIN-42 regulates both the 

sleep-like behavior of lethargus and epidermal stem cell dynamics further supports the model 

of functional conservation between LIN-42 and mammalian PERIOD proteins. The molting 

timer may therefore represent an ancient paradigm for integrating rhythmic and developmental 

processes. Further studies of the molting timer may uncover novel but conserved mechanisms 

by which PERIOD-based oscillators control rhythmic cellular processes in both developing 

and mature animals. 

Contact: gmonsalve@ucla.edu 

Lab: Frand 


165


C. elegans PRG-1 and piRNAs silence target transcripts through a 

secondary 22G-siRNA pathway 

Alexandra Sapetschnig, Eva-Maria Weick, Marloes Bagijn, Leonard Goldstein, Amy 

Cording, Eric Miska 

Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge, United 

Kingdom 

The Piwi proteins of the Argonaute superfamily and their associated Piwi-interacting RNAs 

(piRNAs) are required for normal germline development in animals. In C. elegans, the Piwi 

protein PRG-1 associates with 21U-RNAs (the piRNAs of C. elegans) and is required for Tc3 

transposon silencing. prg-1 mutant animals display germline defects and a reduction in brood 

size. The molecular mechanism of PRG-1/21U-RNA-mediated silencing of target genes is 

currently not understood. 

To analyse piRNA-dependent gene silencing, we generated a transgenic C. elegans strain 

carrying a germline-expressed GFP reporter with a sequence antisense to an endogenous 

21U-RNA. The GFP transgene is silenced in a wild-type background and becomes de-silenced 

in prg-1 mutant animals. High-throughput sequencing revealed prg-1 dependent 22G-siRNAs 

(secondary endo-siRNAs) that are synthesised from the GFP transgene in close proximity 

to the target site. In a candidate gene approach, we identified additional factors required for 

GFP silencing and prg-1 dependent 22G-RNA synthesis including the dicer-related helicase 

drh-3 and genes of the mutator class like mut-16, mut-7 and mut-2/rde-3. We postulate that 

22G-siRNAs are the effector molecules generated downstream of a primary piRNA trigger. 

The gene silencing appears to be achieved by both transcriptional and post-transcriptional 

mechanisms. Since PRG-1 does not localise to the nucleus, transcriptional gene silencing 

might be achieved through a nuclear 22G-siRNA pathway. We have identified a nuclear 

“worm-specific” Argonaute family member HRDE-1/WAGO-9 that could act to silence piRNA 

targets through heterochromatin formation. We currently investigate a potential role of 

heterochromatin-associated factors in the piRNA pathway by a candidate genetic approach 

and ChIP experiments. 

PRG-1 has a conserved catalytic centre (amino acid triad DDH) that is required for “slicing” 

(cleavage) of target mRNAs in other Argonaute proteins. To elucidate the role of the putative 

slicer activity in PRG-1 dependent gene silencing, we generated transgenic strains expressing 

wild-type or a slicer-dead mutant of PRG-1 in the germline. Both transgenes rescue the 

abnormal phenotype observed in prg-1 mutant animals indicating that slicer activity is not 

required for PRG-1 function. 

Contact: as878@cam.ac.uk 

Lab: Miska 

166 



MicroRNA Predictors of Longevity in C. elegans 

Zachary Pincus, Thalyana Smith-Vikos, Frank Slack 

Yale University, New Haven, CT, USA 

Neither genetic nor environmental factors fully account for variability in individual longevity: 

genetically identical invertebrates in homogenous environments often experience no less 

variability in lifespan than outbred human populations. The identification of early-life gene 

expression states that predict future longevity would suggest that lifespan is at least in part 

epigenetically determined. Such ‘’biomarkers of aging,’’ genetic or otherwise, nevertheless 

remain rare. In this work, we sought early-life differences in organismal robustness in 

unperturbed individuals and examined the utility of microRNAs, known regulators of lifespan, 

development, and robustness, as aging biomarkers. We analyzed biometrics of C. elegans 

observed throughout their lives using novel single-animal solid-media culture techniques. 

Additionally, we confirmed these results by rearing worms on individual plates, and mounting 

and recovering worms from slides for single-timepoint imaging at early-adulthood. Early-tomid–adulthood 

measures of homeostatic ability jointly predict 62% of longevity variability. We 

further identified three microRNAs in which early-adulthood expression patterns individually 

predict up to 47% of lifespan differences. Though expression of each increases throughout 

this time, miR-71 and miR-246 correlate with lifespan, while miR-239 anti-correlates. We also 

examined expression of these microRNAs simultaneously in the same worm to identify any 

potential synergistic effects. Two of these three microRNA ‘’biomarkers of aging’’ act upstream 

in insulin/IGF-1–like signaling (IIS) and other known longevity pathways; thus, we infer that 

these microRNAs not only report on but also likely determine longevity. Therefore, fluctuations 

in early-life IIS, due to variation in these microRNAs and from other causes, may determine 

individual lifespan. 

Contact: thalyana.smith-vikos@yale.edu 

Lab: Slack 


167


A Genetic Suppressor Screen in Caenorhabditis elegans for Targets 

of Antipsychotic Drugs: Role of the Nicotinic Acetylcholine Receptor 

Homolog acr-7 

Taixiang Saur, Xin Wang, Limin Hao, Bruce Cohen, Edgar Buttner 

McLean Hospital, Belmont, MA 

We performed the first genetic screen for antipsychotic drug (APD) targets in an animal, a 

genome-wide RNAi screen for Suppressors of Clozapine-induced Larval Arrest (scla genes). 

Using this approach, we identified acr-7, which encodes a homolog of the human a-like 

nicotinic acetylcholine receptors (nAChRs), as a potential APD target. We validated our RNAi 

result by showing that the acr-7(tm863) deletion suppresses clozapine-induced developmental 

delay. A full-length translational Pacr-7::acr-7::gfp fusion construct rescues this phenotype. We 

investigated the specificity of acr-7(lf) suppression by testing 21 other C.e. nAChR subunits and 

found that only acr-7(lf) suppresses clozapine-induced developmental delay. Mutations in cha- 

1 and unc-17 are not suppressors, suggesting that clozapine does not cause developmental 

delay by stimulating Ach release. 

Both translational and transcriptional acr-7::gfp fusion constructs are strongly expressed 

in the pharynx. Clozapine inhibits pharyngeal pumping, and acr-7(lf) suppresses this effect. 

Thus, one mechanism by which clozapine delays development is likely by inhibiting pharyngeal 

pumping. The effects of clozapine on pharyngeal pumping and development are mimicked 

by the nAChR agonists nicotine and levamisole and blocked by the nAChR antagonists DHβ. 

Our results are consistent with the notion that clozapine inhibits pharyngeal pumping, in part, 

by activating ACR-7 receptors in the pharynx. 

Effects of APDs on the spectrum of nAChR subunit combinations have not been tested in 

mammals. Therefore, whether APDs can activate one or more these receptors is an important 

question. α7-nAChR agonists are currently in development for the treatment of psychosis, but 

no known APDs have been demonstrated to act by this mechanism. α-like nAChR signaling is a 

mechanism through which clozapine may produce its therapeutic and/or toxic effects in human. 

Contact: txu@mclean.harvard.edu 

Lab: Buttner 

168 



Characterizing in-host population dynamics of pathogenic bacteria 

during intestinal infection of C. elegans 

Ronen Kopito, Andrzej Nowojewski, Erel Levine 

Department of Physics and FAS Center for Systems Biology, Harvard University 

Host-pathogen interactions drive the progression and outcome of bacterial infection, and are 

believed to be key determinants in evolution of virulence and resistance to infection. Intestinal 

infection of worms by pathogenic bacteria provide and excellent opportunity to characterize 

these interactions and link them to the development and outcome of infection. To this end, 

we developed tools that allow long-time high-resolution imaging of the infection process in 

individual worms. We track the spatiotemporal proliferation of bacteria in a worm intestine from 

the onset of infection until the death of the worm. At the same time, we follow the expression 

of relevant genes in both bacteria and worms. Physiological cues are monitored to evaluate 

the progression of the infection process. Thus, we aim to compose a complete timeline of the 

disease of each individual worm, and to use computational tools to deduce interactions and 

causality. We demonstrate the approach and our preliminary results focusing on “slow killing” 

of C. elegans by P. aeruginosa PA14. We find that bacterial population dynamics in the worm 

intestine is highly unstable even late in the infection process, identify cumulative bacterial 

sub-populations that correlate with infection outcome and immune response, and show how 

individual behavior contributes to variable outcome. 

Contact: rkopito@gmail.com 

Lab: Levine 


169


Dynamics of stress response across the worm unveils cross-tissue 

interactions 

Ronen Kopito, Christian Anderson, Erel Levine 

Department of Physics and FAS Center for Systems Biology, Harvard University 

Small heat shock proteins are mediators of stress response in animals. Accumulation of 

these proteins is linked with resilience to stress as well as with aging and longevity. In addition, 

heat-shock promoters are popular experimental tools, used to induce gene expression. Even 

under optimized conditions worms demonstrate a highly inconsistent accumulation of heat 

shock proteins in response to stress. We carried out a detailed quantitative study of the 

accumulation of Hsp-16.2 in response to stress signals, using microfluidic tools developed 

for imaging gene expression at high spatiotemporal resolution over long periods of time, and 

analysis approaches borrowed from statistical physics. We find that stress response occurs at 

two time scales – short (about 2-3 hours after the onset of stress) and long (around 12 hours), 

followed by slow decay. We show how the total level of Hsp-16.2 across the worm, used as 

a proxy for gene expression in many studies, is in fact unrepresentative of the real complex 

dynamics. Our data suggests that a major contribution to the worm-to-worm variability stems 

from the decay of the stress response signal, implying that heat shock promoters should not 

be used to induce gene expression for long periods of time. Correlations and temporal ordering 

in the response dynamics of different tissues allow us to formulate hypotheses about crosstissue 

interactions. We find similar kinetic features in other stress response pathways, and 

trace them to molecular mediators of tissue-tissue interactions. 

Contact: rkopito@gmail.com 

Lab: Levine 

170 


Contact: mmondoux@holycross.edu 

Lab: Mondoux 


Glucose Stress Regulates Insulin Signaling, Fertility, and Mating in C. 

elegans 

Amanda K. Engstrom1 , Marjorie R. Liggett1 , John A. Hanover2 , Michael W. Krause2 , 

Michelle A. Mondoux1 1 2 College of the Holy Cross, Worcester, MA, National Institutes of Health, 

Bethesda, MD 

Energy homeostasis occupies a central position in biology, as it regulates gene expression, 

signal transduction, cellular survival, fertility, and lifespan. However, the molecular and genetic 

responses to excess nutrients are poorly understood. Using C. elegans as a genetic model 

to study the pathways that respond to nutrient stress, we have identified a number of insulindependent 

processes that are sensitive to glucose stress, including fertility, reproductive timing, 

and dauer formation. Each of these has a different threshold for sensitivity to glucose excess. 

We have further characterized the C. elegans response to excess glucose in both 

hermaphrodites and males. We find that the reduction in fertility and delayed reproductive 

timing are separable phenotypes dependent on glucose exposure during adulthood and 

development, respectively. Glucose stress during development results in a 1-2 day delay in 

reproductive timing but has no effect on adult fertility. Likewise, glucose stress during adulthood 

reduces fertility with no change in the reproductive profile. Glucose stress also reduces the 

ability of hermaphrodites and males to mate, as evidenced by reduced brood sizes and fewer 

male cross-progeny. 

In order to identify the pathways that respond to nutrient stress, we are screening a C. 

elegans RNAi library to identify factors that suppress insulin signaling specifically in the 

presence of glucose stress. This screen will provide insight into how cells respond to nutrient 

stress when insulin signaling is compromised. 


171


172 

NOTES

A 

Aebi, Markus................................ 42, 154 

Agellon, Luis B..................................... 22 

Ahn, Jeong-Min ................................... 99 

Ahn, Soungyub .................................... 94 

Ajredini, Ramadan ............................. 153 

Alla, Ramani ........................................ 51 

Alves, Anna Maria........................ 14, 161 

Andersen, Erik C ............................... 133 

Anderson, Christian ........................... 170 

Antebi, Adam ................................. 26, 38 

Anthony, Hannah L ............................ 150 

Apfeld, Javier ....................................... 37 

Aroian, Raffi ....................................... 152 

Arsenovic, Paul T ................................ 96 

Ashe, Alyson ...................................... 164 

Ashraf, Jasmine M ............................... 71 

Ashrafi, Kaveh ....................... 17, 53, 159 

Au, Catherine......................................... 2 

Avery, Leon .................................... 80, 88 

Awoyinka, Olufadakemi ..................... 145 

Ayyadevara, Srinivas ........................... 51 

B 

Bagijn, Marloes P .............................. 166 

Baker, Keith ....................................... 121 

Bakowski, Malina A .................... 132, 142 

Baldwin, James G.............................. 151 

Balla, Keir M .............................. 133, 139 

Barr, Angela ....................................... 103 

Barra, Donatella................................. 147 

Baugh, L Ryan ......................... 5, 70, 125 

Baugh, Ryan L ..................................... 27 

Baugh, Ryan ........................................ 87 

Baumeister, Ralf .......................... 91, 123 

Belicard, Tony .............................. 31, 134 

Benzing, Thomas ................................. 57 

Ben-Zvi, Anat ......................................... 4 

Bernal, Teresita .................................. 159 

Bethke, Axel......................................... 38 

Bhanot, Gyan....................................... 74 

Author Index 


AUTHOR INDEX 

Bharill, Puneet ..................................... 57 

Bhatia, Aatish....................................... 74 

Blackwell, Leah.................................... 95 

Blackwell, T. Keith ................................ 11 

Bleuler-Martinez, Silvia ...................... 154 

Bloss, Tim A ......................................... 96 

Boehler, Christopher J ......................... 78 

Bolander, Frnklyn F ........................... 162 

Bose, Neelanjan .................................. 38 

Bossard, Carine .................................. 18 

Bouagnon, Aude .................................. 17 

Boxem, Mike ....................................... 34 

Boyd, Lynn ......................................... 127 

Bracciale, Maria P ............................. 131 

Braeckman, Bart P .............. 8, 30, 52, 54 

Branicky, Robyn ................................... 22 

Bratanich, Ana ................................... 135 

Brewer, Heather M................................. 8 

Brey, Christopher W ............................ 79 

Broday, Limor ..................................... 34 

Broggi, Alessandra ............................ 131 

Brul, Stanley ...................................... 128 

Butschi, Alex ................................ 42, 154 

Buttner, Edgar...................... 82, 157, 168 

Button, Emma L ................................. 136 

C 

Cabello, Juan..................................... 144 

Cabreiro, Filipe ...................................... 2 

Cabunoc, Abigail.................................. 45 

Camp II, David G ................................... 8 

Carr, Christopher E .............................. 29 

Carrano, Andrea ................................. 18 

Castelein, Natascha ............................ 52 

Cattie, Douglas J ................................. 97 

Chang, Sandy .................................... 152 

Chen, Albert T ................................ 41, 53 

Chen, Chang-Shi .............................. 137 

Chen, Po-Han ..................................... 98 

Chen, Show-Li ..................................... 98 

Chen, Yutao ......................................... 27 

Chiu, Hao-Chieh ............................... 137 

173


Choe, Keith P .............................113, 114 

Choi, Jinhee......................................... 99 

Chou, Ting-Chen .............................. 137 

Clark, Laura C ................................... 138 

Coburn, Cassandra ............................. 30 

Cohen, Bruce....................... 82, 157, 168 

Colleluori, Vaughn D ............................ 96 

Cook, James M.................................. 145 

Cording, Amy ..................................... 166 

Couillault, Carole ............................... 159 

Crook, Helen M.................................. 129 

Crossgrove, Kirsten ........................... 100 

Crowder, C. Michael ............ 43, 116, 126 

Crowder, Michael ............................... 110 

Cruz, Melissa R ................................. 156 

Cunningham, Katherine ....................... 17 

Cuomo, Christina A ............................ 132 

D 

Darby, Brian ...................................... 160 

Davidson, Andrew........................ 95, 101 

De Bellis, Giovanni ............................ 131 

de Boer, Richard ................................ 128 

De Haes, Wouter ................................. 54 

de la Cruz, Norie.................................. 45 

de Lencastre, Alexandre ...................... 10 

Demoinet, Emilie ................................. 19 

Dennis, Jennifer C ............................. 102 

Denzel, Martin S .................................. 26 

Deonarine, Andrew ............................ 113 

Depuydt, Geert G .................................. 8 

Desjardins, Christopher A .................. 132 

Desjardins, David ............................... 22 

Devanapally, Sindhuja ......................... 44 

Dhondt, Ineke ........................................ 8 

Diederich, Ann-Kristin ......................... 64 

Dillin, Andrew ................................. 18, 47 

Dillman, Adler R ................................. 151 

Diogo, Jesica ..................................... 135 

Driscoll, Monica ....................... 32, 74, 76 

Dumas, Kathleen J .. 3, 38, 41, 53, 55, 63 

Dunbar, Tiffany L................................ 139 

Duong, Adrian ...................................... 45 

Duveau, Fabien ................................... 31 

174 

E 

Edelman, Theresa LB ........................ 103 

Edison, Arthur S................................. 153 

Engholm-Keller, Kasper ....................... 15 

Engstrom, Amanda K ........................ 171 

Eom, Hyun - Jeong .............................. 99 

Estes, Kathleen ................................... 33 

Ewbank, Jonathan J ...................... 1, 159 

F 

Fabretti, Francesca.............................. 57 

Færgeman, Nils J ................................ 15 

Fawcett, Emily M ............................... 104 

Felix, Marie-Anne ............ 9, 31, 134, 138 

Fierro-Gonzalez, Juan Carlos...... 59, 144 

Fitch, David.......................................... 61 

Flibotte, Stephane ........................... 3, 55 

Fonslow, Bryan ................................... 18 

Fontana, Walter ................................... 37 

Frand, Alison R .................................. 165 

Franz, Carl J .......................................... 9 

Fredens, Julius .................................... 15 

Frokjaer-Jensen, Christian ................ 103 

Fu, Donald ........................................... 49 

Fujii, Michihiko ................................... 130 

G 

Gaglia, Marta M ................................... 65 

Gallagher, Thomas L ........................... 80 

Garcia, Anastacia M .................. 105, 120 

Garcia, L Rene .................................... 93 

Garcia, Luis rene ................................... 7 

Gardner, Mona................................... 146 

Garland, Brenda ................................ 100 

Garsin, Danielle A ...................... 143, 156 

Gaugler, Randy.................................... 79 

Gelino, Sara......................................... 56 

Gems, David .................................... 2, 30 

Gharbi, Hakam .................................... 57 

Ghose, Piya ......................................... 74 

Gill, Matthew S .................................... 83 

Glover-Cutter, Kira M ........................... 11 

Go, Junhyeok ...................................... 58 

Goh, Grace YS .................................. 106 

Author Index

Goldstein, Leonard D................. 164, 166 

Golombek, Diego A .............................. 81 

Gonzalez-Barrios, Maria ...................... 59 

Goy, Jo M .................................... 60, 120 

Goya, Maria E...................................... 81 

Graciano, Thomas ............................. 146 

Gravato-Nobre, Maria Joao ....... 138, 140 

Greene, Nick D ...................................... 2 

Gross, Megan .................................... 145 

Guo, Chunfang .................. 41, 53, 63, 68 

Guo, Xiaoyan ......................................... 7 

H 

Haenen, Steven ................................... 54 

Hall, David ..................................... 16, 74 

Hanover, John A ................................ 171 

Hansen, Malene .................... 13, 56, 163 

Hao, Limin ................................... 82, 168 

Harris, Todd W ..................................... 45 

Harrison, Neale.................................... 83 

Hartley, Shannon ............................... 150 

Hartman, Phillip ................................. 130 

Hasegawa, Koichi ............................. 114 

Hashmi, Sanya .................................... 79 

Hashmi, Sarwar ................................... 79 

Haynes, Cole M ................................... 39 

Heimbucher, Thomas ......................... 18 

Hekimi, Siegfried ................................. 22 

Hendrix, Amber .................................... 85 

Hengartner, Michael O................. 42, 154 

Henis-Korenblit, Sivan ....................... 107 

Herman, Michael ....................... 158, 160 

Herrera, R Antonio ............................... 61 

Herndon, Laura A........................... 16, 74 

Hodgkin, Jonathan............. 138, 140, 148 

Horsman, Joseph ................................ 62 

Hou, Nicole S....................................... 84 

Hu, Patrick J ...... 3, 38, 41, 53, 55, 63, 68 

Hu, Queenie ...................................... 108 

Hu, Yan .............................................. 152 

Huang, Anne ........................................ 28 

Hubbard, E. Jane Albert ...................... 69 

Hunter, Tony ....................................... 18 

Hyun, Moonjung ................................ 109 

Author Index 


I 

Ibanez-Ventoso, Carolina .................... 74 

Ihuegbu, Nnamdi ................................ 14 

Irazoqui, Javier E ......................... 14, 161 

Ishii, Naoaki ....................................... 130 

Ishii, Takamasa .................................. 130 

J 

Jablonski, Angela M........................... 141 

Jacobs, Rene....................................... 48 

Jakob, Ursula....................................... 64 

Jansen-Duerr, Pidder........................... 72 

Janssen, Tom ...................................... 90 

Jayamani, Elamparithi ....................... 144 

Jeong, Dae-Eun................................... 65 

Jevince, Angela ................................... 16 

Jevince, Angelina................................. 74 

Jiang, Yanfang ....................................... 9 

Jimenez-Hidalgo, Maria ..................... 144 

Jobson, Meghan ............................ 5, 125 

Jordan, James ..................................... 87 

Jorgensen, Erik M.............................. 103 

Jose, Antony M .................................... 44 

Judkins, Joshua C ............................... 38 

Judy, Meredith ..................................... 28 

K 

Kabir, M. Shahjahan .......................... 145 

Kaeberlein, Matt .................................. 12 

Kagias, Konstantinos ......................... 118 

Kalb, Robert G ................................... 141 

Kammenga, Jan ................................ 158 

Kang, Hae-Sung ................................ 155 

Kao, Aimee W ...................................... 28 

Kasisomayajula, Hema ..................... 162 

Kassa, Berhanu ................................... 52 

Kassim, Maher..................................... 45 

Kenyon, Cynthia J ....................... 28, 107 

Kim, Dennis H.................46, 97, 111, 149 

Kim, Euysoo ................................ 43, 110 

Kim, Jeongho....................................... 85 

Kiontke, Karin ...................................... 61 

Klang, Ida M ........................................ 50 

Knoefler, Daniela ................................. 64 

175


Koniczek, Martin .................................. 64 

Kopito, Ronen ............................ 169, 170 

Kotera, Ippei ........................................ 49 

Krause, Michael W ............................ 171 

Kruglyak, Leonid ................................ 133 

Kubiseski, Terry ................................. 108 

Kuenzler, Markus ............................... 154 

Kulalert, Warakorn ..............................111 

Kumsta, Caroline ............................... 163 

Kunzler, Markus ................................... 42 

Kuo, Cheng-Ju .................................. 137 

Kuroda, Eisuke .................................... 66 

Kurz, Cyril Leopold ............................ 144 

Kwong, Ada ....................................... 106 

L 

Ladage, Mary..................................... 120 

Land, Marianne.................................. 112 

Lapierre, Louis R ................................. 13 

Le Pen, Jeremie ................................ 164 

Le, Hai ................................................. 44 

LeBlanc, Marc-Andre ......................... 101 

Lee, Dongyeop .................................... 65 

Lee, Inhwan ......................................... 85 

Lee, Junho ..................................... 89, 94 

Lee, Kang-Mu ...................................... 58 

Lee, Kuang-Hui.................................... 40 

Lee, Seung-Jae ................................... 65 

Lee, Siu Sylvia ....................................... 6 

Lee, Soon-Young ................................. 67 

Leung, Chi K ...............................113, 114 

Leung, Kit-Yi .......................................... 2 

Levine, Erel................................ 169, 170 

Li, Liming ........................................... 119 

Liang, Jun .......................................... 115 

Liggett, Marjorie R ............................. 171 

Lin, Stephanie...................................... 11 

Lindblom, Tim H........................... 95, 101 

Lithgow, Gordon J................................ 50 

Little, Brent ........................................ 102 

Liu, Ju-Ling .......................................... 22 

Liu, Pingsheng ..................................... 86 

Liu, Shu ............................................. 123 

Liu, Zheng ........................................... 18 

Lo, Dara ............................................... 21 

176 

Lu, Kevin.............................................. 74 

Luallen, Robert J ............................... 142 

Luhachack, Lyly G ............................... 14 

Luo, Shijing .......................................... 71 

M 

Ma, Amy T ......................................... 132 

Mackowiak, Sebastian ....................... 118 

MacNeil, Lesley ................................. 108 

Maeda, Masatomo ............................... 73 

Mahanti, Parag .............................. 30, 38 

Malany, Siobhan ................................ 113 

Maldonado, Anthony T ......................... 96 

Mandel, Abraham ................................ 30 

Mangoni, Maria L ............................... 147 

Mantovani, Julie................................... 19 

Mao, Xianrong R........................ 116, 126 

Mark, Karla .......................................... 50 

Marra, Amanda ................................... 95 

Matthijssens, Filip ................................ 30 

McCallum, Katie C ..................... 143, 156 

McClelland, Michael .......................... 161 

McCulloch, Katherine A ..................... 103 

Meelkop, Ellen ..................................... 90 

Melentijevic, Ilija .................................. 74 

Melki, Ronald ..................................... 119 

Melo, Justine A .................................... 23 

Menzel, Ralph.................................... 117 

Micutkova, Lucia .................................. 72 

Middleton, June H.............................. 146 

Migliori, Maria L ................................... 81 

Miller, Amanda J ................................ 150 

Miller, Dana L ............................... 62, 104 

Miranda-Vizuete, Antonio ............ 59, 144 

Miska, Eric A .............................. 164, 166 

Miskowski, Jennifer A ........................ 145 

Mitani, Shohei .......................... 53, 63, 68 

Mondoux, Michelle A.......................... 171 

Moeller-Jensen, Jakob ........................ 15 

Moerman, Don ................................. 3, 55 

Monsalve, Gabriela C ........................ 165 

Monte, Aaron ..................................... 145 

Mony, Vinod ....................................... 160 

Moon, Hyungmin ................................. 89 

Moore, Brad T ...................................... 87 

Author Index

Morimoto, Richard I ..................... 75, 119 

Mueller, Roman Ulrich ......................... 57 

Mullaney, Brendan ............................. 159 

Mundo-Ocampo, Manuel ................... 151 

Munoz, Manuel .................................... 59 

Murphy, Coleen T .......................... 20, 71 

Myers, Edith M................................... 146 

Mylonakis, Eleftherios........................ 144 

N 

Na, Huimin ........................................... 86 

NAar, Anders ....................................... 48 

Naji, Haaris .......................................... 74 

Nakamura, Ayumi ................................ 28 

Naranjo-Galindo, Francisco Jose ...... 144 

Nehammer, Camilla .......................... 118 

Nguyen, Ken CQ ................................. 16 

Niemuth, Nicholas J............................. 64 

Nishikori, Kenji ............................... 66, 73 

Noiman, Liron ...................................... 17 

Nowojewski, Andrzej.......................... 169 

Nussbaum-Krammer, Carmen I ......... 119 

O 

Ogungbe, Ifedayo Victor ..................... 83 

Ohashi-Kobayashi, Ayako ............. 66, 73 

Olahova, Monika................................ 129 

Olivi, Massimiliano ............................. 147 

Onken, Brian........................................ 32 

O’Rourke, Delia ................................. 148 

Orphan, Victoria J .............................. 151 

Orton, Kai ........................................... 75 

P 

Padilla, Pamela A......... 60, 102, 105, 120 

Padmanabha, Divya .......................... 121 

Pagano, Daniel J ............................... 149 

Palleschi, Claudio ...................... 131, 147 

Pandey, Santosh ............................... 124 

Parashar, Archana ............................ 124 

Park, Donha................................... 21, 84 

Park, Kyung-Won ............................. 119 

Park, Sang-Kyu ................................... 67 

Park, Seul-Ki........................................ 67 

Author Index 


Pasquinelli, Amy E ............................... 25 

Pedrajas, Jose Rafael ....................... 144 

Petyuk, Vladislav A ................................ 8 

Pincus, Zachary ................................. 167 

Pircher, Haymo .................................... 72 

Pocock, Roger .................................. 118 

Podolska, Agnieszka ........................ 118 

Pollok, Robert H .................................. 88 

Polzin, Andy ......................................... 68 

Powell, Jennifer R.............................. 150 

Powell, Megan ................................... 101 

Powell-Coffman, Jo Anne .................. 124 

Price, Milena ........................................ 50 

Price, Rebecca ................................. 148 

Q 

Qi, Wenjing .......................................... 91 

Qin, Zhao ............................................. 69 

R 

Rajewsky, Nikolaus ............................ 118 

Ravikumar, Snusha ............................. 44 

Reddy, Kirthi C ..................................... 97 

Renshaw, Hilary..................................... 9 

Richardson, Claire E............................ 97 

Riddle, Donald L .................................. 21 

Robinson, Joseph D .......................... 150 

Rodriguez, Pedro................................. 50 

Roessel Larsen, Martin........................ 15 

Rohlfing, Anne-Katrin......................... 122 

Romanowski, Andres ........................... 81 

Rongo, Christopher ............................. 74 

Rottiers, Veerle ................................... 48 

Rougvie, Ann E .................................. 103 

Roy, Richard .................................. 19, 92 

Rubin, Charles ................................... 112 

Runkel, Eva D.................................... 123 

Ruvkun, Gary................................. 23, 29 

Ryu, Eun-A .......................................... 65 

S 

Sackett, Peter .................................... 100 

Safavi, Arash ..................................... 152 

Safra, Modi ........................................ 107 

177


Saldanha, Jenifer............................... 124 

Salehpour, Ali....................................... 40 

Sandrof, Moses ................................. 125 

Santarelli, Maria L .............................. 131 

Sapetschnig, Alexandra ..................... 166 

Sapir, Amir ................................... 34, 151 

Sarto, Maria S.................................... 131 

Saur, Taixiang ............................ 157, 168 

Savage-Dunn, Cathy ......................... 115 

Schermer, Bernhard ............................ 57 

Schindler, Adam J ................................ 70 

Schoofs, Liliane ............................. 54, 90 

Schroeder, Frank C ....................... 30, 38 

Schubert, Mario ................................. 154 

Schulze, Ekkehard............................. 123 

Schunck, Wolf-Hagen ........................ 117 

Scott, Barbara A................................. 126 

Sesar, Jillian L ................................... 152 

Shah, Leena ........................................ 74 

Shah, Mitalie ........................................ 76 

Shai, Nadav ........................................... 4 

Shanmugam, Nilesh .............................. 8 

Shapira, Michael .......................... 40, 155 

Shemesh, Netta ..................................... 4 

Sherwood, David R.............................. 70 

Shi, Cheng ........................................... 71 

Shi, Xiaoqi ........................................... 45 

Shih, Hung-Jen .................................... 41 

Shim, Jiwon ......................................... 89 

Shin, Jisun ........................................... 89 

Shiraishi, Hirohisa.......................... 66, 73 

Shmookler Reis, Robert J.................... 51 

Simonetta, Sergio H ............................ 81 

Simske, Jeff ......................................... 35 

Skibinski, Gregory A .......................... 127 

Slack, Frank J .............................. 10, 167 

Smelkinson, Margery G ............... 33, 139 

Smith, Michael ................................... 145 

Smith, Reuben ................................... 128 

Smith, Richard D ................................... 8 

Smith-Vikos, Thalyana ....................... 167 

Smolders, Arne ...................................... 8 

Snoek, Basten ................................... 158 

Soukas, Alexander A............................ 29 

Stein, Lincoln D ................................... 45 

178 

Steinberg, Christian EW .................... 117 

Sternberg, Paul W ....................... 34, 151 

Storm, Nadia J ..................................... 26 

Stormo, Gary D.................................... 14 

Stroud, Dave...................................... 148 

Stroustrup, Nicholas ............................ 37 

Stupp, Gregory S ............................... 153 

Stutz, Katrin ................................. 42, 154 

Su, Po-An ............................................ 49 

Suda, Hitoshi ..................................... 130 

Sun, Chun-Ling.................... 43, 110, 126 

Sunde, Roger A ................................... 78 

Suzuki, Hiroshi..................................... 49 

Swoboda, Peter ........................... 59, 144 

Syu, Wan-Jr ...................................... 137 

Szumowski, Suzannah ........................ 33 

T 

Taferner, Andrea .................................. 72 

Talwar, Amish....................................... 74 

Tanji, Takahiro ................................ 66, 73 

Taubert, Stefan ...................... 21, 84, 106 

Tavernarakis, Nektarios ....................... 72 

Taylor, Rebecca C ............................... 47 

Tazearslan, Cagdas ............................ 51 

Temmerman, Liesbet ........................... 90 

Thamsen, Maike .................................. 64 

Thijs Koorman, Thijs ........................... 34 

Toth, Marton......................................... 74 

Troemel, Emily R . 33, 132, 133, 139, 142 

Tsao, Yeou-Ping................................... 98 

Tsur, Assaf .......................................... 34 

Twumasi-Boateng, Kwame .......... 40, 155 

U 

Uccelletti, Daniela ...................... 131, 147 

Ueda, Yuki ........................................... 66 

V 

Van Assche, Roel ................................ 54 

van der Hoeven, Ransome ................ 156 

van der Spek, Hans ........................... 128 

Van Gilst, Marc .................................. 159 

Vantipalli1, Maithili C ........................... 50 

Author Index

Veal, Elizabeth A ........................ 129, 136 

Visvikis, Orane ..................................... 14 

Voisine, Cindy ...................................... 75 

Vora, Mehul ......................................... 76 

W 

Walhout, Marian ................................ 108 

Walker, Amy K ..................................... 48 

Wang, David .......................................... 9 

Wang, Xin .................................. 157, 168 

Wang, Ying ........................................ 113 

Wang, Ziyi .......................................... 158 

Ward, Jordan D ................................. 159 

Watts, Jennifer .............................. 36, 48 

Weick, Eva-Maria .............................. 166 

White, Corin V ................................... 160 

Williams, Travis W ......................... 53, 63 

Wilson, Iain BH .................................... 42 

Wohlschlager, Therese ........................ 42 

Wolf, Tim .............................................. 91 

Wollam, Joshua ................................... 38 

Wollenberg, Amanda C ................ 14, 161 

Wu, Ching-Ming ................................ 137 

Wu, Guang ............................................ 9 

X 

Xie, Fang ............................................... 8 

Author Index 


Xie, Meng ............................................ 92 

Xue, Jian........................................ 74, 76 

Y 

Yamamoto, Keith R ............................ 159 

Yan, Zhi ..................................... 133, 139 

Yanase, Sumino .................................. 77 

Yang, Charles ...................................... 21 

Yasuda, Kayo .................................... 130 

Yates, Jonathan .................................. 18 

Yoon, Sang Sun ................................... 58 

Yoshimoto, Jennifer ............................. 85 

Yoshina, Sawako ..................... 53, 63, 68 

You, Young-Jai ............... 80, 85, 109, 121 

Yu, Charles ........................................ 126 

Z 

Zanni, Elena ...................................... 131 

Zhang, Jun........................................... 79 

Zhang, Liusuo ...................................... 93 

Zhang, Peng ........................................ 86 

Zhao, Guoyan ........................................ 9 

Zimmerman, Anna M ........................... 38 

Zucker, David....................................... 50 

179

VE. 

DR. 

NIVERSITY 

ELM 

D R. 

UNIVERSITY BUILDINGS, ACCOMMODATIONS, PARKING and POINTS OF INTEREST 

Conference Site Location Accommodation Location Parking Lot Location Point of Interest Location 

1. Memorial Union C1 A. Lowell Hall F2 Lot 6 C1 University Bookstore D2 

2 Union South & Hotel B2 B. Chadbourne Hall C2 Lot 17 A2 Walgreens D2 

C. University Inn D2 Lot 29 C3 Walgreens Pharmacy D2 

D. Doubletree Hotel E3 Lot 46 D2 Monona Terrace G2 

E Dahlmann Campus Inn D2 Lot 83 D2 Overture Center F2 

1 

2 

3 

2012 

CAMPUS 

AVE. 

BREESE 

TER. 

DR. 

Aging, Metabolism, Stress, Pathogenesis, and Small RNAs in C. elegans 

P17 

Camp Randall 

Stadium 

Thursday, July 12–Sunday, July 15, 2012 

A B C D E 

F 

ENGINEERING 

Union South 

and Hotel 

2 

Chadbourne 

Hall 

B 

Memorial Union 

P6 

1 

Fountain 

Walgreens 

Pharmacy 

P29 

University 

Bookstore 

Lowell Hall 

Walgreens 

Lake St. 

Parking Ramp 

P83 

P46 

A 

E 

Dahlmann 

Campus Inn 

C 

University 

Inn 

D 

Doubletree 

Hotel 

A B C D E 

F 

Overture 

Center 

State 

Capitol 

G 

Walkway 

Monona 

Terrace 

LAKE 

MONONA 

G 

1 

2 

3

Phone 

• 

N 

W 

Studio B 

E 

Studio A 

Entrance 

 

Play Circle 

Theater 

Wisconsin Union 

Theater 

Park Street 

Entrance 

Stairs 

Stairs to studiosW 

Rosewood 

Room 

Stairs to 

2nd floor 

CE Aging Locations 

Poster Sessions 

u Great Hall (4th floor) 

v Reception Room (4th floor) 

Party & Dance 

w Tripp Commons (2nd floor East) 

Dinner 

x Inn Wisconsin (2nd floor East) 

Plenary Sessions 

Union South-See Campus Map 

S 

Great Hall 

Phone 

• 

M 

Langdon 

Room 

3rd Floor West 

NOTE: Studios are not handicapped 

accessible. Accessible from West stairs only. 

W 

Stairs 

To Union Theater 

Box 

Office 

Stairs 

Hotel Rooms 

 

Class of'24 

Recept. Room 

Elevator 

Browsing 

Library 

Stairs 

Stairs 

Stairs 

To Park Street 

4th Floor 

Elevator 

Capitol View 

Main Lounge 

Outside Terrace Area 

Stairs 

Rathskeller 

MEMORIAL UNION 

Board 

Room 

Beefeaters 

Room 

To Terrace 

W/M 

Stairs 

Stairs 

Tripp Deck 

To MU Games Room (downstairs) 

Paul Bunyan Room 

Art Gallery 

Elevator 

Main Entrance 

W 

Round 

Table 

Room 

Elevator 

Od l Madison Room 

rs 

M 

 

Tripp Commons 

Elevator 

Stairs 

M W 

Stairs 

Phone• 

Stairs 

Lakefront onLangdon 

Elevator 

 

Central Reservations 

and Conference Services 

MU Floor Legend 

Floor Room in Use 

Fourth 

Third 

Second 

First 

3rd Floor East 

NOTE: Accessible from East elevator/ 

East end of building only. 

2nd Floor 

Profile Room 

Inn Wisconsin Room 

M 

W 

Inn WI Deck 

1st Floor 

Stairs Elevator Information Desk 

Tyme 

Phones 

Stairs 

Daily Scoop 

Deli 

Front 

Entrance

Level 1 

R A N D A L L A V E N U E 

S T A I R S 

E N T R A N C E 


Badger Market 

S T A I R S 

Ginger Root 

Harvest Grains 

Union South Building Map 

Level 2 

R A N D A L L A V E N U E 

S T A I R S 

E L E V A T O R 


S T A I R S 

S T A I R S 

S T A I R S 

CE Aging Locations 

Registration/Conference HQ 

Varsity Lounge (2nd floor) 

Plenary Sessions 

Marquee (2nd floor) 

Breakfast 

Varsity Hall (2nd floor) 

Luncheon Buffet 

Varsity Hall (2nd floor) 


S T A I R S 

S T A I R S 

The Roost 

Varsity Hall 

Prairie Fire 

Urban Slice 

T H E P L A Z A 

S E R V I C E 

Varsity Lounge 

Coffeehouse Lounge 

S T A I R S 

S T A I R S 


W . J O H N S O N 


SUN GARDEN 

ELEVATOR 

M E N ’ S R E S T R O O M 

W O M E N ’ S R E S T R O O M 

Daily Scoop 

D A Y T O N S T R E E T 

S T O R A G E 

T H E P L A Z A 


S T A I R S 

Sun Garden 

Gallery 1308 

Wiscard 

VIP Info Desk 




W . J O H N S O N 

Sift & Winnow 

M E N ’ S 

R E S T R O M 

S T A I R S 

W O M E N ’ S 

R E S T R O O M 

SUN GARDEN 

ELEVATOR 

Traditions 

D A Y T O N S T R E E T 

S T A I R S 

Wisconsin Idea 

The Marquee 

S T O R A G E 

S T A I R S 

Lounge 

Alumni 

Governance 

Scholars 

UW Credit Union 

S T A I R S 

M A I N 


M E N ’ S 

R E S T R O O M 

The Sett 

M A I N 


Hotel Desk 

Hotel Lobby 

WOMEN’S 

RESTROOM 

Upper 

Climbing Wall 

WUD Office 

The Sett Balcony 

The Sett 


1st Floor 

Office 

Space 

S T A I R S 



Fifth Quarter Studio 

Info Lounge 

S T A I R S 

T H E O R C H A R D 

D R I V E 

T U R N A R O U N D 


2nd Floor 

T H E O R C H A R D

PROGRAM & ABSTRACTS - Wisconsin Union - University of ...

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