Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTS256. The Unique family of Telomere-Linked Helicases in Fungi. Olga Novikova 1,2 , Mark Farman 2 . 1) Department of Biological Sciences, University atAlbany, Albany, NY; 2) Department of Plant Pathology, University of Kentucky, Lexington, KY.Subtelomeres and telomeres are highly dynamic regions of eukaryotic chromosomes and their maintenance is crucial for cellular function. Severalhelicases are known to be involved in maintenance of telomere integrity, e.g. RecQ-like helicases such as human BLM or WRN helicases. Curiously, RecQlikehelicase genes are found in very close proximity to telomeres in several fungal species. In the present study we performed comprehensive survey ofthese Telomere-Linked Helicases (TLHs) in 101 fully-sequenced fungal genomes. The TLHs were widely yet sporadically distributed among fungal speciesbeing present in 46 species belonging to all investigated groups except Zygomycetes. The TLHs were also unique to fungi. Many of the TLH genes werefound either next to telomeres or at the ends of contigs, providing indirect evidence that they are telomere associated. To date, the TLH gene families arethe only examples where the chromosomal positions of member genes are absolutely conserved across a kingdom. Despite the seemingly conservativepositions of the TLH genes on the chromosomes, the genes themselves are clearly not well conserved because they were found in only in half of the fungalgenomes surveyed. The TLHs were highly divergent from one another and demonstrated complex evolutionary histories that reflect recurrent cycles oftelomere crisis and recovery. Their telomere association leads us to hypothesize that the TLHs are involved either in telomere maintenance, or in therecovery processes associated with telomere crisis.257. Evolution of proteins containing intein- and Hedgehog-like Vint domains in Fungi. Olga Novikova, Marlene Belfort. Department of BiologicalSciences and RNA Institute, University at Albany, Albany, NY.Inteins are protein sequences that autocatalytically splice themselves out of the protein precursors - analogous to introns - and ligate the flanking regionsinto a functional protein. Intein-containing genes are present in all three kingdoms of life. Moreover, it was shown that the C-terminal domain ofeukaryotic Hedgehog (Hh) proteins has sequence similarity to inteins. The Hh pathway is one of the fundamental signal transduction pathways in animaldevelopment and is also involved in stem-cell maintenance and carcinogenesis. Two distinct domains can be found in Hh - the N-terminal ‘Hedge’ domain(HhN), and the intein-like C-terminal ‘Hog’ or ‘Hint’ domain (HhC). The hedgehog pathway is absent from Fungi. However, other families of proteins werefound containing Hog/Hint-like domains. Representatives from one of these families carry the von Willebrand factor type A (vWA) domain in addition tothe Hog/Hint-like domain. These domains are called Vint (von Willebrand Hint-like). Vint-containing proteins were initially reported for plants, fungi andsome metazoa. We explored the diversity of Vint-containing proteins, their distribution and evolutionary history in fungi. Vint-containing proteins arewidely distributed among fungal lineages; however, they are absent from some of the fungal species and entire fungal groups (e.g. Saccharomyces). Basedon the evolutionary pattern, we propose a modular model of the evolution for Vint-containing proteins. While the vWA domain seems to be the corefunctional unit, an additional domain, the U-box, is a recent acquisition. The vWA and U-box combination was found exclusively in fungi. The Vint domainis highly conserved and is likely under purifying selection. The functional role of Vint-containing proteins and the Vint domain in particular is the subject forfurther studies. This research has been supported by NIH grant GM44844.258. The genome and development-dependent transcriptome of Pyronema confluens: a window into fungal evolution. Stefanie Traeger 1 , Jason Stajich 2 ,Stefanie Pöggeler 3 , Minou Nowrousian 1 . 1) Department of General & Molecular Botany, Ruhr University Bochum, 44780 Bochum, Germany; 2) Departmentof Plant Pathology and Microbiology, University of California Riverside, CA 92521, USA; 3) Institute of Microbiology and Genetics, Department of Geneticsof Eukaryotic Microorganisms, Georg-August University, 37077 Göttingen, Germany.In the last decade, genomes of many filamentous ascomycetes have been sequenced and are invaluable for the analysis of the evolution of species andfor understanding their physiological and morphological properties. However, while there are at least ten genome sequences available for each of themore derived groups of filamentous ascomycetes (Sordariomycetes, Leotiomycetes, Eurotiomycetes, Dothideomycetes), only one genome from the basalgroup of Pezizomycetes has been sequenced, namely that the black truffle, a fungus with a specialized life-style and fruiting body. Therefore, wesequenced the genome and transcriptome of the Pezizomycete Pyronema confluens, a saprobe with typical apothecia as fruiting bodies. The genome wasassembled from a combination of Roche/454 and Illumina/Solexa reads. It has a size of 50 Mb, and a predicted 13369 protein-coding genes. P. confluens ishomothallic, and we found two MAT loci that are not fused or in close proximity, and encode an alpha domain and an HMG domain transcription factor.Only the MAT1-2 locus is flanked by the conserved apn2 gene, whereas both MAT loci are flanked by a pair of paralogous genes not found in this locationin other ascomycetes. Thus, the P. confluens MAT loci might reflect an evolutionary transition state on the way towards the relatively conserved genomicarrangement of MAT loci in higher ascomycetes. Sexual development in P. confluens is light-dependent, and qRTPCR analyses of predicted photoreceptorgenes showed that all are upregulated by light. Fruiting body formation is stimulated only by part of the visible spectrum, and we are currentlyinvestigating the effect of different wavelengths on development and gene expression. For RNA-seq analysis, we used three conditions: growth in the light,and two different conditions allowing only vegetative growth. We analyzed expression levels for genes with different degrees of evolutionary conservationto find out if genes with different lineage-specificities are preferentially expressed under any of the conditions investigated. Interestingly, the highestpercentage of genes upregulated during sexual development is found among the P. confluens orphan genes. This might indicate that, similar to thesituation in animals, genes associated with sexual reproduction evolve more rapidly than genes with other functions.259. Genome and transcriptome analysis of the mycoparasite Clonostachys rosea. Kristiina Nygren 1 , Mikael Brandström Durling 1 , Chatchai Kosawang 2 ,Dan Funck Jensen 1 , Magnus Karlsson 1 . 1) Forest Mycology and Plant Pathology, Swedish Univesity of Agricultural Sciences, Uppsala, Sweden; 2)Department of Plant Biology and Biotechnology, University of Copenhagen, Denmark.The ascomycete Clonostachys rosea is an efficient antagonist against a range of fungal plant pathogens, presumably as a consequence from itsmycoparasitic lifestyle. C. rosea is therefore used as a biological control agent against pathogens threatening agricultural crops. Still, very little is knownabout the mechanisms behind the mycoparasitism in C. rosea. By comparative genomics using C. rosea and publically available genome sequences fromclosely related species exhibiting different lifestyles we aim at exploring evolution of genes important for the transition into a mycoparasitic lifestyle. Andby analyzing the transcriptome during interactions with different fungal plant pathogens we intend to get a deeper understanding on the gene expressionof secreted enzymes during initial attack but also to study potential specialization towards specific fungal prey species. For these purposes we havesequenced the genome of C. rosea strain IK726. In addition we have performed an RNAseq study to investigate the gene expression during interactionswith the two plant pathogenes Botrytis cinerea and Fusarium graminearum. Our draft genome of C. rosea (strain IK726) reveals that the species has alarger genome than it’s closest sequenced relatives (58 Mb, which is 40 - 75 % larger than the 7 closest sequenced species). Preliminary comparativegenome analyses indicate that the mycoparasitic function of C. rosea differs from earlier findings in mycoparasites of the closely related genusTrichoderma. For example, in C. rosea we find a significant expansion of ABC-transporter genes.184