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Ulrich Kuck - One of the best experts on this subject based on the ideXlab platform.
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rna editing during sexual development occurs in distantly related filamentous Ascomycetes
Genome Biology and Evolution, 2017Co-Authors: Ines Teichert, Ulrich Kuck, Tim A Dahlmann, Minou NowrousianAbstract:RNA editing is a post-transcriptional process that modifies RNA molecules leading to transcript sequences that differ from their template DNA. A-to-I editing was found to be widely distributed in nuclear transcripts of metazoa, but was detected in fungi only recently in a study of the filamentous ascomycete Fusarium graminearum that revealed extensive A-to-I editing of mRNAs in sexual structures (fruiting bodies). Here, we searched for putative RNA editing events in RNA-seq data from Sordaria macrospora and Pyronema confluens, two distantly related filamentous Ascomycetes, and in data from the Taphrinomycete Schizosaccharomyces pombe. Like F. graminearum, S. macrospora is a member of the Sordariomycetes, whereas P. confluens belongs to the early-diverging group of Pezizomycetes. We found extensive A-to-I editing in RNA-seq data from sexual mycelium from both filamentous Ascomycetes, but not in vegetative structures. A-to-I editing was not detected in different stages of meiosis of S. pombe. A comparison of A-to-I editing in S. macrospora with F. graminearum and P. confluens, respectively, revealed little conservation of individual editing sites. An analysis of RNA-seq data from two sterile developmental mutants of S. macrospora showed that A-to-I editing is strongly reduced in these strains. Sequencing of cDNA fragments containing more than one editing site from P. confluens showed that at the beginning of sexual development, transcripts were incompletely edited or unedited, whereas in later stages transcripts were more extensively edited. Taken together, these data suggest that A-to-I RNA editing is an evolutionary conserved feature during fruiting body development in filamentous Ascomycetes.
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the ww domain protein pro40 is required for fungal fertility and associates with woronin bodies
Eukaryotic Cell, 2007Co-Authors: Ines Engh, Christian Würtz, Hanspeter Rottensteiner, Konstanze Witzelschlomp, Hai Yu Zhang, Birgit Hoff, Minou Nowrousian, Ulrich KuckAbstract:Fruiting body formation in Ascomycetes is a highly complex process that is under polygenic control and is a fundamental part of the fungal sexual life cycle. However, the molecular determinants regulating this cellular process are largely unknown. Here we show that the sterile pro40 mutant is defective in a 120-kDa WW domain protein that plays a pivotal role in fruiting body maturation of the homothallic ascomycete Sordaria macrospora. Although WW domains occur in many eukaryotic proteins, homologs of PRO40 are present only in filamentous Ascomycetes. Complementation analysis with different pro40 mutant strains, using full-sized or truncated versions of the wild-type pro40 gene, revealed that the C terminus of PRO40 is crucial for restoring the fertile phenotype. Using differential centrifugation and protease protection assays, we determined that a PRO40-FLAG fusion protein is located within organelles. Further microscopic investigations of fusion proteins with DsRed or green fluorescent protein polypeptides showed a colocalization of PRO40 with HEX-1, a Woronin body-specific protein. However, the integrity of Woronin bodies is not affected in mutant strains of S. macrospora and Neurospora crassa, as shown by fluorescence microscopy, sedimentation, and immunoblot analyses. We discuss the function of PRO40 in fruiting body formation.
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comparative analysis of the mating type loci from neurospora crassa and sordaria macrospora identification of novel transcribed orfs
Molecular Genetics and Genomics, 2000Co-Authors: Stefanie Pöggeler, Ulrich KuckAbstract:The mating-type locus controls mating and sexual development in filamentous Ascomycetes. In the heterothallic ascomycete Neurospora crassa, the genes that confer mating behavior comprise dissimilar DNA sequences (idiomorphs) in the mat a and mat A mating partners. In the homothallic fungus Sordaria macrospora, sequences corresponding to both idiomorphs are located contiguously in the mating-type locus, which contains one chimeric gene, Smt A-3, that includes sequences which are similar to sequences found at the mat A and mat a mating-type idiomorphs in N. crassa. In this study, we describe the comparative transcriptional analysis of the chimeric mating-type region of S. macrospora and the corresponding region of the N. crassa mat a idiomorph. By means of RT-PCR experiments, we identified novel intervening sequences in the mating-type loci of both Ascomycetes and, hence, concluded that an additional ORF, encoding a putative polypeptide of 79 amino acids, is present in the N. crassa mat a idiomorph. Furthermore, our analysis revealed co-transcription of the novel gene with the mat a-1 gene in N. crassa. The same mode of transcription was found in the corresponding mating-type region of S. macrospora, where the chimeric Smt A-3 gene is co-transcribed with the mat a-specific Smt a-1 gene. Analysis of a Smt A-3 cDNA revealed optional splicing of two introns. We believe that this is the first report of co-transcription of protein-encoding nuclear genes in filamentous fungi. Possible functions of the novel ORFs in regulating mating-type gene expression are discussed.
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the pro1 gene from sordaria macrospora encodes a c6 zinc finger transcription factor required for fruiting body development
Genetics, 1999Co-Authors: Sandra Masloff, Stefanie Pöggeler, Ulrich KuckAbstract:During sexual morphogenesis, the filamentous ascomycete Sordaria macrospora differentiates into multicellular fruiting bodies called perithecia. Previously it has been shown that this developmental process is under polygenic control. To further understand the molecular mechanisms involved in fruiting body formation, we generated the protoperithecia forming mutant pro1, in which the normal development of protoperithecia into perithecia has been disrupted. We succeeded in isolating a cosmid clone from an indexed cosmid library, which was able to complement the pro1(-) mutation. Deletion analysis, followed by DNA sequencing, subsequently demonstrated that fertility was restored to the pro1 mutant by an open reading frame encoding a 689-amino-acid polypeptide, which we named PRO1. A region from this polypeptide shares significant homology with the DNA-binding domains found in fungal C6 zinc finger transcription factors, such as the GAL4 protein from yeast. However, other typical regions of C6 zinc finger proteins, such as dimerization elements, are absent in PRO1. The involvement of the pro1(+) gene in fruiting body development was further confirmed by trying to complement the mutant phenotype with in vitro mutagenized and truncated versions of the pro1 open reading frame. Southern hybridization experiments also indicated that pro1(+) homologues are present in other sexually propagating filamentous Ascomycetes.
Rupert De Wachter - One of the best experts on this subject based on the ideXlab platform.
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Evolutionary Relationships Among Higher Fungi Inferred From Small Ribosomal-subunit Rna Sequence-analysis
Systematic and Applied Microbiology, 1993Co-Authors: Annick Wilmotte, Yves Van De Peer, Anne Goris, Sabine Chapelle, Raymond De Baere, Bart Nelissen, Jean-marc Neefs, Gregoire L. Hennebert, Rupert De WachterAbstract:The primary structure of the small ribosomal subunit RNA. (SSU rRNA) was determined for 13 species belonging to 10 ascomycete families and for the basidiomycetous anamorphic yeast Rhodotorula glutinis. The sequences were fitted into an alignment of all hitherto published complete or nearly complete eukaryotic small subunit rRNA sequences. The evolutionary relationships within the fungi were examined by construction of a tree from 87 SSU rRNA sequences, corresponding to 71 different species, by means of a distance matrix method and bootstrap analysis. It confirms the early divergence of the zygomycetes and the classical division of the higher fungi into basidiomycetes and Ascomycetes. The basidiomycetes are divided into true basidiomycetes and ustomycetes. Within the Ascomycetes, the major subdivisions hemiAscomycetes and euAscomycetes can be recognized. However, Schizosaccharomyces pombe does not belong to the cluster of the hemiAscomycetes, to which it is assigned in classical taxonomic schemes, but forms a distinct lineage. Among the euAscomycetes, the plectomycetes and the pyrenomycetes can be distinguished. Within the hemiAscomycetes, the polyphyly of genera like Pichia or Candida and of families like the Dipodascaceae and the Saccharomycetaceae can be observed.
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Phylogenetic Relationships among Ascomycetes and Ascomycete-like Yeasts as Deduced from Small Ribosomal Subunit RNA Sequences
Systematic and Applied Microbiology, 1992Co-Authors: Lydia Hendriks, Yves Van De Peer, Anne Goris, Jean-marc Neefs, Gregoire L. Hennebert, Marc Vancanneyt, Karel Kersters, Jean-francois Berny, Rupert De WachterAbstract:The primary structure of the small ribosomal subunit RNA (srRNA) molecule of the type strains of the ascosporogenous yeasts Debaryomcyes hansenii, Pichia anomala (synonym: Hansenula anomala), Pichia membranaefaciens, Schizosaccharomyces pombe, Zygosaccharomyces rouxii and Dekkera bruxellensis was determined. The srRNA sequences were aligned with previously published sequences from fungi, including those of 5 candida species, and an evolutionary tree was inferred The srRNA results were compared with chemotaxonomic criteria, e.g. the coenzyme Q system. The heterogeneity of the genera Candida and Pichia is clearly reflected by the srRNA analysis.
Simone Ottonello - One of the best experts on this subject based on the ideXlab platform.
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genome wide inventory of metal homeostasis related gene products including a functional phytochelatin synthase in the hypogeous mycorrhizal fungus tuber melanosporum
Fungal Genetics and Biology, 2011Co-Authors: Angelo Bolchi, Roberta Ruotolo, Gessica Marchini, E Vurro, Luigi Sanita Di Toppi, Annegret Kohler, Emilie Tisserant, Francis Martin, Simone OttonelloAbstract:Ectomycorrhizal fungi are thought to enhance mineral nutrition of their host plants and to confer increased tolerance toward toxic metals. However, a global view of metal homeostasis-related genes and pathways in these organisms is still lacking. Building upon the genome sequence of Tuber melanosporum and on transcriptome analyses, we set out to systematically identify metal homeostasis-related genes in this plant-symbiotic ascomycete. Candidate gene products (101) were subdivided into three major functional classes: (i) metal transport (58); (ii) oxidative stress defence (32); (iii) metal detoxification (11). The latter class includes a small-size metallothionein (TmelMT) that was functionally validated in yeast, and phytochelatin synthase (TmelPCS), the first enzyme of this kind to be described in filamentous Ascomycetes. Recombinant TmelPCS was shown to support GSH-dependent, metal-activated phytochelatin synthesis in vitro and to afford increased Cd/Cu tolerance to metal hypersensitive yeast strains. Metal transporters, especially those related to Cu and Zn trafficking, displayed the highest expression levels in mycorrhizae, suggesting extensive translocation of both metals to root cells as well as to fungal metalloenzymes (e.g., laccase) that are strongly upregulated in symbiotic hyphae.
Minou Nowrousian - One of the best experts on this subject based on the ideXlab platform.
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rna editing during sexual development occurs in distantly related filamentous Ascomycetes
Genome Biology and Evolution, 2017Co-Authors: Ines Teichert, Ulrich Kuck, Tim A Dahlmann, Minou NowrousianAbstract:RNA editing is a post-transcriptional process that modifies RNA molecules leading to transcript sequences that differ from their template DNA. A-to-I editing was found to be widely distributed in nuclear transcripts of metazoa, but was detected in fungi only recently in a study of the filamentous ascomycete Fusarium graminearum that revealed extensive A-to-I editing of mRNAs in sexual structures (fruiting bodies). Here, we searched for putative RNA editing events in RNA-seq data from Sordaria macrospora and Pyronema confluens, two distantly related filamentous Ascomycetes, and in data from the Taphrinomycete Schizosaccharomyces pombe. Like F. graminearum, S. macrospora is a member of the Sordariomycetes, whereas P. confluens belongs to the early-diverging group of Pezizomycetes. We found extensive A-to-I editing in RNA-seq data from sexual mycelium from both filamentous Ascomycetes, but not in vegetative structures. A-to-I editing was not detected in different stages of meiosis of S. pombe. A comparison of A-to-I editing in S. macrospora with F. graminearum and P. confluens, respectively, revealed little conservation of individual editing sites. An analysis of RNA-seq data from two sterile developmental mutants of S. macrospora showed that A-to-I editing is strongly reduced in these strains. Sequencing of cDNA fragments containing more than one editing site from P. confluens showed that at the beginning of sexual development, transcripts were incompletely edited or unedited, whereas in later stages transcripts were more extensively edited. Taken together, these data suggest that A-to-I RNA editing is an evolutionary conserved feature during fruiting body development in filamentous Ascomycetes.
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INVESTIGATION Functional Analysis of Developmentally Regulated Genes chs7 and sec22 in the Ascomycete
2016Co-Authors: Sordaria Macrospora, Stefanie Traeger, Minou NowrousianAbstract:ABSTRACT During sexual development, filamentous Ascomycetes form complex, three-dimensional fruiting bodies for the generation and dispersal of spores. In previous studies, we identified genes with evolutionary conserved expression patterns during fruiting body formation in several fungal species. Here, we present the functional analysis of two developmentally up-regulated genes, chs7 and sec22, in the ascomycete Sordaria macrospora. The genes encode a class VII (division III) chitin synthase and a soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) protein, respectively. De-letion mutants of chs7 had normal vegetative growth and were fully fertile but showed sensitivity toward cell wall stress. Deletion of sec22 resulted in a reduced number of ascospores and in defects in ascospore pigmentation and germination, whereas vegetative growth was normal in the mutant. A SEC22-EGFP fusion construct under control of the native sec22 promoter and terminator regions was expressed during different stages of sexual development. Expression of several development-related genes was deregulated in the sec22 mutant, including three genes involved in melanin biosynthesis. Our data indicate that chs7 is dispens-able for fruiting body formation in S. macrospora, whereas sec22 is required for ascospore maturation and germination and thus involved in late stages of sexual development. KEYWORD
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a novel polyketide biosynthesis gene cluster is involved in fruiting body morphogenesis in the filamentous fungi sordaria macrospora and neurospora crassa
Current Genetics, 2009Co-Authors: Minou NowrousianAbstract:During fungal fruiting body development, hyphae aggregate to form multicellular structures that protect and disperse the sexual spores. Analysis of microarray data revealed a gene cluster strongly upregulated during fruiting body development in the ascomycete Sordaria macrospora. Real time PCR analysis showed that the genes from the orthologous cluster in Neurospora crassa are also upregulated during development. The cluster encodes putative polyketide biosynthesis enzymes, including a reducing polyketide synthase. Analysis of knockout strains of a predicted dehydrogenase gene from the cluster showed that mutants in N. crassa and S. macrospora are delayed in fruiting body formation. In addition to the upregulated cluster, the N. crassa genome comprises another cluster containing a polyketide synthase gene, and five additional reducing polyketide synthase (rpks) genes that are not part of clusters. To study the role of these genes in sexual development, expression of the predicted rpks genes in S. macrospora (five genes) and N. crassa (six genes) was analyzed; all but one are upregulated during sexual development. Analysis of knockout strains for the N. crassarpks genes showed that one of them is essential for fruiting body formation. These data indicate that polyketides produced by RPKSs are involved in sexual development in filamentous Ascomycetes.
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the ww domain protein pro40 is required for fungal fertility and associates with woronin bodies
Eukaryotic Cell, 2007Co-Authors: Ines Engh, Christian Würtz, Hanspeter Rottensteiner, Konstanze Witzelschlomp, Hai Yu Zhang, Birgit Hoff, Minou Nowrousian, Ulrich KuckAbstract:Fruiting body formation in Ascomycetes is a highly complex process that is under polygenic control and is a fundamental part of the fungal sexual life cycle. However, the molecular determinants regulating this cellular process are largely unknown. Here we show that the sterile pro40 mutant is defective in a 120-kDa WW domain protein that plays a pivotal role in fruiting body maturation of the homothallic ascomycete Sordaria macrospora. Although WW domains occur in many eukaryotic proteins, homologs of PRO40 are present only in filamentous Ascomycetes. Complementation analysis with different pro40 mutant strains, using full-sized or truncated versions of the wild-type pro40 gene, revealed that the C terminus of PRO40 is crucial for restoring the fertile phenotype. Using differential centrifugation and protease protection assays, we determined that a PRO40-FLAG fusion protein is located within organelles. Further microscopic investigations of fusion proteins with DsRed or green fluorescent protein polypeptides showed a colocalization of PRO40 with HEX-1, a Woronin body-specific protein. However, the integrity of Woronin bodies is not affected in mutant strains of S. macrospora and Neurospora crassa, as shown by fluorescence microscopy, sedimentation, and immunoblot analyses. We discuss the function of PRO40 in fruiting body formation.
Angelo Bolchi - One of the best experts on this subject based on the ideXlab platform.
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genome wide inventory of metal homeostasis related gene products including a functional phytochelatin synthase in the hypogeous mycorrhizal fungus tuber melanosporum
Fungal Genetics and Biology, 2011Co-Authors: Angelo Bolchi, Roberta Ruotolo, Gessica Marchini, E Vurro, Luigi Sanita Di Toppi, Annegret Kohler, Emilie Tisserant, Francis Martin, Simone OttonelloAbstract:Ectomycorrhizal fungi are thought to enhance mineral nutrition of their host plants and to confer increased tolerance toward toxic metals. However, a global view of metal homeostasis-related genes and pathways in these organisms is still lacking. Building upon the genome sequence of Tuber melanosporum and on transcriptome analyses, we set out to systematically identify metal homeostasis-related genes in this plant-symbiotic ascomycete. Candidate gene products (101) were subdivided into three major functional classes: (i) metal transport (58); (ii) oxidative stress defence (32); (iii) metal detoxification (11). The latter class includes a small-size metallothionein (TmelMT) that was functionally validated in yeast, and phytochelatin synthase (TmelPCS), the first enzyme of this kind to be described in filamentous Ascomycetes. Recombinant TmelPCS was shown to support GSH-dependent, metal-activated phytochelatin synthesis in vitro and to afford increased Cd/Cu tolerance to metal hypersensitive yeast strains. Metal transporters, especially those related to Cu and Zn trafficking, displayed the highest expression levels in mycorrhizae, suggesting extensive translocation of both metals to root cells as well as to fungal metalloenzymes (e.g., laccase) that are strongly upregulated in symbiotic hyphae.
