Schizosaccharomyces versatilisrepresents a distinct evolutionary lineage

Abstract

AbstractThe fission yeast speciesSchizosaccharomyces japonicusis currently divided into two varieties –S. japonicusvar.japonicusandS. japonicusvar.versatilis. Here we examine the var.versatilisisolate CBS5679. The CBS5679 genome shows 88% coding sequence identity to the reference genome ofS. japonicusvar.japonicusat the coding sequence level, with phylogenetic analyses suggesting that it has split from theS. japonicuslineage 25 million years ago. The CBS5679 genome contains a reciprocal translocation between chromosomes 1 and 2, together with several large inversions. The products of genes linked to the major translocation are associated with “metabolism” and “cellular assembly” ontology terms. We further show that CBS5679 does not generate viable progeny with the reference strain ofS. japonicus. Although CBS5679 shares closer similarity to the “type” strain of var.versatilisas compared to S.japonicus, it is not identical to the type strain, suggesting population structure within var.versatilis. We recommend that the taxonomic status ofS. japonicusvar.versatilisis raised, with it being treated as a separate species,Schizosaccharomyces versatilis.Take-awayThe taxonomic status ofSchizosaccharomyces versatilisis addressed.S. versatilisdiverged fromS. japonicusaround 25 million years ago.S. versatilisdoes not produce viable progeny in crosses withS. japonicus.S. versatilishas a reciprocal translocation between chromosomes 1 and 2.The Gene Ontology terms for genes in the translocations are enriched for terms connected to “metabolism” and “cellular assembly”.