Fungal genome and mating system transitions facilitated by chromosomal translocations involving intercentromeric recombination

• DOI: 10.1371/journal.pbio.2002527
• Publication Date: 2017-08-11T21:33:37Z
• Authors: Sheng Sun; Vikas Yadav; R. Blake Billmyre; Christina A. Cuomo; Minou Nowrousian; Liuyang Wang; Jean-Luc Souciet; Teun Boekhout; Betina Porcel; Patrick Wincker; Joshua A. Granek; Kaustuv Sanyal; Joseph Heitman
• Keywords: Synteny

Species within the human pathogenic Cryptococcus species complex are major threats to public health, causing approximately 1 million annual infections globally. amylolentus is most closely known related of complex, and it non-pathogenic. Additionally, while have bipolar mating systems with a single large type (MAT) locus that represents derived state in Basidiomycetes, C. has tetrapolar system 2 MAT loci (P/R HD) located on different chromosomes. Thus, studying will shed light transition from species, as well its possible link origin evolution pathogenesis. In this study, we sequenced, assembled, annotated genomes isolates, CBS6039 CBS6273, which sexual interfertile. Genome comparison between isolates identified boundaries complete gene contents P/R HD loci. Bioinformatic chromatin immunoprecipitation sequencing (ChIP-seq) analyses revealed that, similar those regional centromeres (CENs) enriched species-specific transposable repetitive DNA elements. found neither nor physically linked centromere amylolentus, regions their respective show overall synteny genomes, both exhibit genetic linkage during meiosis, suggesting presence recombinational suppressors and/or epistatic interactions MAT-CEN intervening regions. Furthermore, genomic comparisons provide evidence multiple chromosomal rearrangements mediated by intercentromeric recombination occurred descent lineages common ancestor. Taken together, our findings support model was initiated an ectopic event centromeric elements shared This translocation brought onto same chromosome, further then resulted becoming eventually fusing form contiguous now extant species.