| Title: | Polyporales genomes reveal the genetic architecture underlying tetrapolar and bipolar mating systems |
| Author(s): | James TY; Sun S; Li W; Heitman J; Kuo HC; Lee YH; Asiegbu FO; Olson A; |
| Address: | "Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109" |
| ISSN/ISBN: | 0027-5514 (Print) 0027-5514 (Linking) |
| Abstract: | "The process of mating in Basidiomycota is regulated by homeodomain-encoding genes (HD) and pheromones and G protein-coupled pheromone receptor genes (P/R). Whether these genes are actually involved in determining mating type distinguishes mating systems that are considered tetrapolar (two locus) from bipolar (one locus). Polyporales are a diverse group of wood-decay basidiomycetes displaying high variability in mating and decay systems. Many of the bipolar species appear to be brown-rot fungi, and it has been hypothesized that there is a functional basis for this correlation. Here we characterize mating genes in recently sequenced Polyporales and other Agaricomycete genomes. All Agaricomycete genomes encode HD and pheromone receptor genes regardless of whether they are bipolar or tetrapolar. The HD genes are organized into a MAT-HD locus with a high degree of gene order conservation among neighboring genes, with the gene encoding mitochondrial intermediate peptidase consistently syntenic but no linkage to the P/R genes. To have a complete dataset of species with known mating systems we determined that Wolfiporia cocos appears to be bipolar, using the criterion that DNA polymorphism of MAT genes should be extreme. Testing the correlation of mating and decay systems while controlling for phylogenetic relatedness failed to identify a statistical association, likely due to the small number of taxa employed. Using a phylogenetic analysis of Ste3 proteins, we identified clades of sequences that contain no known mating type-specific receptors and therefore might have evolved novel functions. The data are consistent with multiple origins of bipolarity within the Agaricomycetes and Polyporales, although the alternative hypothesis that tetrapolarity and bipolarity are reversible states needs better testing" |
| Keywords: | "Fungal Proteins/genetics *Genes, Mating Type, Fungal Genome Components *Genome, Fungal Molecular Sequence Data Phylogeny Polyporales/classification/*genetics/physiology Receptors, Pheromone/genetics Prf bifactorial character correlations synteny unifactor;" |
| Notes: | "MedlineJames, Timothy Y Sun, Sheng Li, Wenjun Heitman, Joseph Kuo, Hsiao-Che Lee, Yong-Hwan Asiegbu, Frederick O Olson, Ake eng Research Support, Non-U.S. Gov't England 2013/08/10 Mycologia. 2013 Nov-Dec; 105(6):1374-90. doi: 10.3852/13-162. Epub 2013 Aug 8" |
