From two to many: Multiple mating types in Basidiomycetes

Publication date: Available online 10 December 2015 Source:Fungal Biology Reviews Author(s): Ursula Kües Fungi do not have different sexes characterized by specific morphological organs but control sexual development by physiological differences defined by mating types. While other lineages in the fungal kingdom have only two distinct mating types, multiple mating types are common in the Basidiomycetes, presumably for outcomes related to enhanced outbreeding. Mating types in Basidiomycetes are determined by genes that encode two types of homeodomain transcription factors (HD genes) and by genes that encode lipopeptide pheromones and pheromone receptors (PR genes). In the tetrapolar mushroom Coprinopsis cinerea, these genes reside at two distinct loci on different chromosomes and regulate distinct steps in dikaryon formation and maintenance and fruiting body formation for sexual reproduction by controlling the expression of large sets of genes. The matA (HD) locus in C. cinerea has an estimated 160 alleles in nature, and the matB (PR) locus has 79. The respective products of both loci interact with each other in a lock-and-key manner. Proteins encoded in allelic sets of mating type genes recognize each other and interact in order to either form a functional transcription factor complex that is transported into the nucleus (matA proteins) or to initiate a pheromone response signaling cascade (matB proteins). Products encoded by the same matA or matB allele do not interac...
Source: Fungal Biology Reviews - Category: Biology Source Type: research