Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSlike pheromones or quorum sensing molecules, but a secreted protein. We successfully identified this protein as the conserved adhesin Cfl1 in theextracellular matrix. The released Cfl1 acts as an auto-induction signal to stimulate neighboring cells to phenocopy Cfl1-expressing cells. We propose thatsuch adhesin/matrix-initiated communication system exists in divergent microbes and our work represents the first adhesin/matrix-mediated signalingmechanism in simple eukaryotes.128. The PacC Signal Transduction Pathway regulates Sexual Development in Neurospora crassa. Chinnici Jennifer, Arnold Jason, Stephen J. Free. DeptBiological Sci, SUNY Univ, Buffalo, Buffalo, NY.As is common in the ascomycetes, the Neurospora crassa life cycle has both asexual and sexual developmental phases. Sexual development in N. crassais characterized by the formation of a protoperithecium, fertilization, and the maturation of the protoperithecium to form a perithecium. In a screeningexperiment, we identified over 600 isolates from the N. crassa single gene deletion library that are unable to complete sexual development. Many of theseare affected in the process of anastomosis, and we have previously reported on these mutants. We now report on the other female developmentdefective mutants identified in our screening experiments. Co-segregation and complementation experiments were carried out on these mutants and weidentified 80 genes that are required for female development (in addition to the 24 genes needed for anastomosis). We find that these genes fall into 5general classes: 1) signal transduction pathway genes (25 genes), 2) transcription factor genes (7 genes), 3) chromatin remodeling genes (17 genes), 4)genes required for autophagy (11 genes), and 5) miscellaneous genes (20 genes). The PacC pathway genes are among the identified signal transductionpathway genes needed for female development. The activation of the PacC signal transduction pathway is a key signaling event in sexual development.Our experiments also suggest that autophagy and anastomosis are important for the movement of nutrients from the hyphal tissues supporting thedeveloping perithecium.129. Aspergillus flavus MAP kinase AflMpkB positively regulates developmental process but not aflatoxin production. Sang-Cheol Jun 1,2 , Dong-Soon Oh 1 ,Jong-Hwa Kim 1 , Kwang-Yeop Jahng 2 , Kap-Hoon Han 1 . 1) Dept. of Pharmaceutical Engineering, Woosuk Univ, Wanju, Korea; 2) Div. of Biological Sciences,Chonbuk National University, Jeonju, Korea.Developmental process of eukaryotes is controlled by the multiple regulatory systems including signal transduction pathways and transcription factors.One of the central signaling mechanisms includes mitogen-activated protein kinase (MAPK) pathway that transfer extracellular signals into nucleus,generating cellular responses. Previously, we have showed that Aspergillus nidulans MpkB, the yeast Fus3 MAP kinase ortholog, regulates sexualdevelopment and secondary metabolism. Here, we identified and characterized the ortholog of the A. nidulans mpkB gene in Aspergillus flavus, AflmpkB,to understand whether the AflmpkB gene has conserved function with A. nidulans mpkB. Deletion of AflmpkB did not affect hyphal growth but showedreduced conidia production Furthermore, AflmpkB null strain didn’t produce any sclerotia while WT and recipient strain produced a lot of sclerotia innormal conditions. However, loss of AflmpkB resulted in normal aflatoxin biosynthesis, suggesting that the major function of AflmpkB is positive regulationof conidiation, sclerotia development but not mycotoxin production. These results indicate that A. nidulans and A. flavus MpkB have conserved anddivergent roles in development and secondary metabolism.130. Subcellular localization and kinase activity of GK4, a Phytophthora infestans GPCR-PIPK involved in actin cytoskeleton organisation. Chenlei Hua 1 ,Harold Meijer 1 , Kiki Kots 1,2 , Tijs Ketelaar 2 , Francine Govers 1 . 1) Laboratories of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PBWageningen, The Netherlands; 2) Laboratories of Cell Biology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.For dispersal and host infection plant pathogens largely depend on asexual spores. Pathogenesis and sporulation are complex processes that aregoverned by various cellular signaling networks including G-protein and phospholipid signaling. Oomycetes possess a family of novel proteins called GPCR-PIPKs (GKs) that are composed of a seven trans-membrane spanning (7-TM) domain fused to a phosphatidylinositol phosphate kinase (PIPK) domain.Based on this domain structure GKs are anticipated to link G-protein and phospholipid signalling pathways. Our studies in the potato late blight pathogenPhytophthora infestans revealed involvement of one of twelve GKs (i.e. PiGK4) in spore development, hyphal elongation and infection. Moreover, ectopicexpression in P. infestans of subdomains of PiGK1 and PiGK4 fused to a fluorescent protein showed that the GPCR domain targets the GKs to membranessurrounding different cellular compartments. To further elucidate the function of the PIPK domain we tested kinase activity of PiGK4 both in vivo and invitro and analysed the relationship between PiGK4, phosphoinositide signaling and the organisation of the actin cytoskeleton using complementation inyeast combined with various live-cell markers.131. External calcium ions and deletion of per-1 gene suppressed the abnormal morphology of och-1 and frost mutants in Neurospora crassa. MasayukiKamei, Yuko Tsukagoshi, Shinpei Banno, Masakazu Takahashi, Akihiko Ichiishi, Makoto Fujimura. Faculty of Life Sciences, Toyo University, ORA-GUN,GUNMA, Japan.Calcium ions play important roles in the growth and development in filamentous fungi. The frost mutant show slow growth and hyperbranchingphenotypes that can be corrected by Ca 2+ addition in Neurospora crassa. The frost gene is an ortholog of S. cerevisiae cdc1 which encodes putative Mn 2+ -dependent lipid phosphatase. We found that the abnormal morphology of the och-1 mutant was quite similar to that of the frost mutant and itsabnormality was also corrected by external Ca 2+ . The och-1 gene encodes an alpha-1,6-mannosyltransferase that is probably involved in sugar processingfor GPI-anchor proteins. In yeast, the mutation of per1 gene, encoding a protein is required for GPI remodeling pathway, suppresses the abnormal growthphenotype of cdc1 mutant. To examine the effect of per-1 gene, an ortholog of per1 in S. cerevisiae, on the phenotypes of the frost and och-1 mutants, weisolated two double mutants, frost; Dper-1 and och-1; Dper-1. Although per-1 gene disruptant showed the normal growth phenotype, per-1 gene deletionsignificantly suppressed the slow growth and hyperbranching phenotypes of frost and also och-1 mutants. Addition of Ca 2+ did not affect the growth andmorphology of the two double mutants. These results suggest the connection between FROST and OCH-1 may participate in lipid remodeling or calciumsignaling in Neurospora crassa.132. Functional analysis of carbonic anhydrases from the filamentous ascomycete Sordaria macrospora. Ronny Lehneck 1 , Piotr Neumann 2 , AchimDickmanns 2 , Ralf Ficner 2 , Stefanie Pöggeler 1 . 1) Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August-University Göttingen; 2) Institute of Microbiology and Genetics, Department of Molecular Structural Biology, Georg-August-University Göttingen.Carbonic anhydrases (CA) are widely distributed enzymes, which catalyzes the reversible hydration of carbon dioxide to bicarbonate and protons. Basedon their amino acid sequence and structure, they can be divided into five distinct groups (a, b, g, d, x) which share no sequence similarity and havesupposable evolved independently. All known fungal CAs belong either to the a-class or to the b-class. Our model organism Sordaria macrospora encodesat least four carbonic anhydrases: three of the b type, termed cas1, cas2 and cas3 (carbonic anhydrase of Sordaria) and one a-type, termed cas4.Previously, the functions of CAS1, CAS2 and CAS3 have been intensively studied (Elleuche and Pöggeler 2009) and displayed an involvement in fruiting-27th Fungal Genetics Conference | 153