Evolutionary erosion of yeast sex chromosomes by mating-type switching accidents.

ABSTRACT: We investigate yeast sex chromosome evolution by comparing genome sequences from 16 species in the family Saccharomycetaceae, including data from genera Tetrapisispora, Kazachstania, Naumovozyma, and Torulaspora. We show that although most yeast species contain a mating-type (MAT) locus and silent HML and HMR loci structurally analogous to those of Saccharomyces cerevisiae, their detailed organization is highly variable and indicates that the MAT locus is a deletion hotspot. Over evolutionary time, chromosomal genes located immediately beside MAT have continually been deleted, truncated, or transposed to other places in the genome in a process that is gradually shortening the distance between MAT and HML. Each time a gene beside MAT is removed by deletion or transposition, the next gene on

SUBMITTER: Gordon JL 

PROVIDER: S-EPMC3250169 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature