Gene Order Evolution and Paleopolyploidy in Hemiascomycete Yeasts

摘要: The wealth of comparative genomics data from yeast species allows the molecular evolution these eukaryotes to be studied in great detail. We used “proximity plots” visually compare chromosomal gene order information 14 hemiascomycetes, including recent Genolevures survey, Saccharomyces cerevisiae. Contrary original reports, we find that strongly support hypothesis S. cerevisiae is a degenerate polyploid. Using alone, 70% genome can mapped into “sister” regions tile together with almost no overlap. This map confirms and extends sister constructed previously by using duplicated genes, an independent source information. Combining duplication assigns essentially whole regions, largest gap being only 36 genes long. 16 centromere form eight pairs, indicating ancestor chromosomes underwent complete doubling; alternatives such as segmental duplications ruled out. Gene arrangements Kluyveromyces lactis four other agree quantitatively what would expected if they diverged before its polyploidization. In contrast, exiguus, servazzii, Candida glabrata show higher levels adjacency conservation, more cases imperfect suggesting split lineage after finding confirmed sequences around C. TRP1 IPP1 loci, which it contains derived same event