Periodic Reporting for period 1 - MatTypeEvol (Evolution of fungal mating-type chromosomes)
Période du rapport: 2016-03-01 au 2018-02-28
One of the main findings of the study were that fungal mating type chromosomes evolve in a very similar way to sex chromosomes in plants and animals. It was previously thought that the typical sex chromosome structure (with strong asymmetry and one highly degenerated chromosome, such as the Y in humans) was caused by the existence of separate sexes and alleles specifically beneficial in one sex or the other. Given that fungi display mating types (with very few loci defining mating compatibility) and do not have separate sexes, finding the exact same chromosome structure in fungi and plants/animals with traditional sex chromosomes implies that separate sexes alone cannot be responsible for sex chromosome architecture.
The project also investigated the evolution of suppressed recombination in Microbotryum and documented for the first time repeated independent events of recombination suppression in closely related species. Recombination suppression leads to higher gamete compatibility in these selfing species and is under strong selection. Comprehensive genomic analyses indicated at least five independent events of recombination suppression, with distinct chromosomal arrangements and different ages.