title: Genome-wide gene expression profiling of fertilization competent mycelium in opposite mating types in the heterothallic fungus Podospora anserina.
abstract: BACKGROUND
  Mating-type loci in yeasts and ascomycotan filamentous fungi (Pezizomycotina) encode master transcriptional factors that play a critical role in sexual development. Genome-wide analyses of mating-type-specification circuits and mating-type target genes are available in Saccharomyces cerevisiae and Schizosaccharomyces pombe; however, no such analyses have been performed in heterothallic (self-incompatible) Pezizomycotina. The heterothallic fungus Podospora anserina serves as a model for understanding the basic features of mating-type control. Its mat+ and mat- mating types are determined by dissimilar allelic sequences. The mat- sequence contains three genes, designated FMR1, SMR1 and SMR2, while the mat+ sequence contains one gene, FPR1. FMR1 and FPR1 are the major regulators of fertilization, and this study presents a genome-wide view of their target genes and analyzes their target gene regulation.
  
  
  RESULTS
  The transcriptomic profiles of the mat+ and mat- strains revealed 157 differentially transcribed genes, and transcriptomic analysis of fmr1(-) and fpr1(-) mutant strains was used to determine the regulatory actions exerted by FMR1 and FPR1 on these differentially transcribed genes. All possible combinations of transcription repression and/or activation by FMR1 and/or FPR1 were observed. Furthermore, 10 additional mating-type target genes were identified that were up- or down-regulated to the same level in mat+ and mat- strains. Of the 167 genes identified, 32 genes were selected for deletion, which resulted in the identification of two genes essential for the sexual cycle. Interspecies comparisons of mating-type target genes revealed significant numbers of orthologous pairs, although transcriptional profiles were not conserved between species.
  
  
  CONCLUSIONS
  This study represents the first comprehensive genome-wide analysis of mating-type direct and indirect target genes in a heterothallic filamentous fungus. Mating-type transcription factors have many more target genes than are found in yeasts and exert a much greater diversity of regulatory actions on target genes, most of which are not directly related to mating.
authors: Univ Paris-Sud, Institut de Génétique et Microbiologie UMR8621, Orsay, France.
authors: Frédérique
authors: F
authors: Bidard
authors: Jinane
authors: J
authors: Aït Benkhali
authors: Evelyne
authors: E
authors: Coppin
authors: Sandrine
authors: S
authors: Imbeaud
authors: Pierre
authors: P
authors: Grognet
authors: Hervé
authors: H
authors: Delacroix
authors: Robert
authors: R
authors: Debuchy
mesh_terms: D020869:Gene Expression Profiling / Q000379:methods*; D049770:Genes, Mating Type, Fungal / Q000235:genetics; D025282:Mycelium / Q000235:genetics*; D048468:Podospora / Q000235:genetics*