Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSmutants in IME1, IME2, KAR4, and NDT80 are blocked in sporulation. Mutants in IME4, KAR4, and UME6 also confer a vegetative growth defect. IME4expression was found during vegetative growth while IME2 was not detected under these conditions. We performed transcriptional profiling of nonsporulatingstrains and determined a core set of about 50 down-regulated sporulation specific genes in these mutants. Interestingly, this set of downregulatedgenes is upregulated in the A. gossypii ste12 mutant providing regulatory evidence of the hypersporulation phenotype of this mutant. Othergenes identified in the RNAseq data indicated that during development of sporangia metabolic genes for nutrient uptake are active. Therefore weperformed Return-To-Growth assays with mutants inhibited in the sporulation pathway. These strains were kept under conditions in which the wild typeinitiates sporulation. This lead to induction of sporangium formation, a stage at which these strains remained. Supply of new nutrients resulted in hyphaloutgrowth in all mutants indicating that after initiation of the sporulation program A. gossypii can reverted to vegetative growth at different stages. Inaddition we identified differential regulation of two endoglucanases encoded by ENG1 and ENG2. While ENG1 was not differentially regulated, ENG2 wasdown-regulated in e.g. ime1 but strongly up-regulated in ste12. Deletion analysis of ENG2 showed that Eng2 is required for hyphal fragmentation intoindividual sporangia. We can thus provide a detailed overview of the genetic regulation of sporulation in A. gossypii. A comparison with S. cerevisiaehighlights the role of KAR4 in sporulation upstream of IME1. Finally, our study provides further evidence that the pheromone signaling response MAPKcascadein A. gossypii has a regulatory control function over sporulation alongside regulation of sporulation by nutritional cues.201. VELVET is regulated by ENV1 and impacts development of Trichoderma reesei. Hoda Bazafkan 1 , Doris Tisch 2 , Monika Schmoll 1 . 1) Health &Environment - Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria; 2) Vienna University of Technology, Institute of ChemicalEngineering, Vienna.In Trichoderma reesei (teleomorph Hypocrea jecorina), light is a crucial environmental factor for initiation of sexual development and considerablyinfluences expression of glycoside hydrolases. In both processes, the light regulatory protein ENV1 plays a key role. Transcriptome analysis revealed thatvel1 (encoding the VELVET orthologue) transcription is regulated by the carbon source in the medium. Moreover, ENV1 negatively regulates vel1 in light.Genes coregulated with vel1 are enriched in functions of amino acid metabolism as well as carbon metabolism and include three non ribosomal peptidesynthases (NRPS). This regulatory pattern supports a connection of vel1 with primary and secondary metabolism also in T. reesei. VELVET is known to be aregulator of sexual and asexual development in fungi. Also for T. reesei a function in development was likely, as several genes involved in sexualdevelopment are coregulated with vel1. Investigation of strains lacking the T. reesei orthologue vel1 under various nutritional, light- and temperatureconditions showed that VEL1 is essential for conidiation and growth of aerial hyphae. Moreover, in crossing assays, sexual development with strainslacking vel1 was delayed and in contrast to the wild-type never occurred in constant darkness. When vel1 was missing in both mating partners, no fruitingbodies were formed. Although male fertility was intact, female fertility was found to be dependent on the presence of vel1. Strains lacking the lightregulator gene env1 are able to undergo sexual development with wild-type strains, but in crosses of two strains lacking env1, no fruiting bodies areformed in light. This defect is assumed to be caused by a deregulation of the pheromone system in these strains. Interestingly, also strains lacking vel1 areunable to mate with env1 deletion mutants in light. Together with the regulatory connection between these genes, these findings support a function ofvel1 in the same pathway as env1. We conclude that VEL1 in T. reesei regulates sexual and asexual development and is connected to the light responsepathway via ENV1.202. Sexual reproduction and mating type function in the penicillin producing fungus Penicillium chrysogenum. Julia Böhm 1 , Birgit Hoff 1 , Simon Wolfers 1 ,Céline O'Gorman 2 , Paul Dyer 2 , Stefanie Pöggeler 3 , Ulrich Kück 1 . 1) Christian Doppler Laboratory for Fungal Biotechnology, Ruhr-Universität Bochum,Universitätsstr. 150, 44780 Bochum, Deutschland; 2) School of Biology, University of Nottingham, University Park, Nottingham, NG7 2RD, U.K; 3) AbteilungGenetik eukaryotischer Mikroorganismen, Institut für Mikrobiologie und Genetik, Georg-August Universität Göttingen, 37077 Göttingen, Deutschland.Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present day industrial source of theantibiotic penicillin with a world market value of about 600 million € per year. The species has been considered asexual for over 100 years and despiteconcerted efforts it has not been possible to induce sexual reproduction. However, we recently were able to detect mating type loci in different strains,indicating a sexual lifecycle. Isolates, carrying opposite mating types, were found in near-equal proportion in nature and we observed transcriptionalexpression of mating type loci as well as pheromone and pheromone receptor genes [1]. Utilising knowledge of mating-type (MAT) gene organization wenow describe conditions under which a sexual cycle can be induced leading to the production of cleistothecia and meiotic ascospores, which were similarto those described recently for Eupenicillium crustaceum [2]. Evidence of recombination was obtained using both molecular and phenotypic markers. Thenewly identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant topenicillin production.Furthermore, the MAT1-1-1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a widerange of genes including those regulating penicillin production, hyphal morphology and conidial formation, all traits of biotechnological relevance. Forfunctional characterization MAT1-1-1 knockout and overexpression strains were generated and analyzed. These discoveries of a sexual cycle and MATgene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.[1] Hoff B, Pöggeler S, Kück U (2008) Eighty years after its discovery, Fleming`s Penicillium strain discloses the secret of its sex. Eukaryot Cell 7: 465-470[2] Pöggeler S, O'Gorman CM, Hoff B, Kück U (2011) Molecular organization of the mating-type loci in the homothallic ascomycete Eupenicilliumcrustaceum. Fungal Biol. 115: 615-624.203. Exponentiate complexity: non-mating GPCRs in the basidiomycete Schizophyllum commune. Daniela Freihorst, Susann Erdmann, Erika Kothe.Institute for Microbiology, Dept. Microbial Communication, Friedrich Schiller University, Jena, Germany.The filamentous fungus S. commune is a model organism for sexual development of basidiomycetes. Numerous studies revealed the importance of twogene loci, A and B, responsible for tetrapolar mating and sexual development. Both occur in multiallelic subloci leading to a large number of differentspecificities in nature (9 to 32 depending on locus), which then control compatibility or abortion of mating. While A codes for homeodomain transcriptionfactors, B codes for a pheromone/receptor system. The B-receptors (Ste3-like, seven transmembrane domains, G-protein coupled) recognize pheromonesof non-self specificity and induce signal transduction pathways and specific gene regulation. After sequencing of strain H4-8 four new Ste3-like GPCRs,homologous to the known B-specific ones, were found. Three of the four B-receptor like genes (brls) are located close to the B-locus. Their function isunknown, because a B-locus defective strain without any interactions seen in B-dependent development still contains those four GPCRs, which obviouslydo not respond to any wild type pheromone. However, our results indicate their importance since sequence identity - analyzed by PCR and sequencing -between unrelated strains was found arguing for conservation of these genes. Gene expression was first observed by Reverse Transcriptase PCR as well asMicroarray analyses, which disproved the theory that brls are pseudo genes. Expression was then investigated by quantitative Real Time PCR duringmating interaction and in monokaryotic strains, which showed comparable results only between gene brl4 and the true mating receptor bar2. Also RNA170