Stable Hypermutators Revealed by the Genomic Landscape of Genes Involved in Genome Stability Among Yeast Species

作者：Carla Gonçalves, Jacob L. Steenwyk, David C. Rinker, Dana A. Opulente, Abigail L. LaBella, Marie‐Claire Harrison, John F. Wolters, Xiaofan Zhou, Xing‐Xing Shen, Shay Covo, Marizeth Groenewald, Chris Todd Hittinger, Antonis Rokas · 发表于：Molecular Biology and Evolution · 年份：2025 · DOI：10.1093/molbev/msaf285 · 被引用次数：4 · 研究领域：Fungal and yeast genetics research、DNA Repair Mechanisms、Yeasts and Rust Fungi Studies

Mutator phenotypes are short-lived due to the rapid accumulation of deleterious mutations. Yet, recent observations reveal that certain fungi can undergo prolonged accelerated evolution after losing genes involved in DNA repair. Here, we surveyed 1,154 yeast genomes representing nearly all known yeast species of the subphylum Saccharomycotina (phylum Ascomycota) to examine the relationship between reduced gene repertoires broadly associated with genome stability functions (eg DNA repair, cell cycle) and elevated evolutionary rates. We identified 3 distantly related lineages-encompassing 12% of species-that had both the most streamlined sets of genes involved in genome stability (specifically DNA repair) and the highest evolutionary rates in the entire subphylum. Two of these "faster-evolving lineages" (FELs)-a subclade within the order Pichiales and the Wickerhamiella/Starmerella (W/S) clade (order Dipodascales)-are described here for the first time, while the third corresponds to a previously documented Hanseniaspora FEL. Examination of genome stability gene repertoires revealed a set of genes predominantly absent in these 3 FELs, suggesting a potential role in the observed acceleration of evolutionary rates. In the W/S clade, genomic signatures are consistent with a substantial mutational burden, including pronounced A|T bias and endogenous DNA damage. Interestingly, we found that the W/S clade also contains DNA repair genes possibly acquired through horizontal gene transfe...