Spontaneous Polyploids and Antimutators Compete During the Evolution of Saccharomyces cerevisiae Mutator Cells.

ABSTRACT: Mutations affecting DNA polymerase exonuclease domains or mismatch repair (MMR) generate "mutator" phenotypes capable of driving tumorigenesis. Cancers with both defects exhibit an explosive increase in mutation burden that appears to reach a threshold, consistent with selection acting against further mutation accumulation. In Saccharomyces cerevisiae haploid yeast, simultaneous defects in polymerase proofreading and MMR select for "antimutator" mutants that suppress the mutator phenotype. We report here that spontaneous polyploids also escape this "error-induced extinction" and routinely outcompete antimutators in evolved haploid cultures. We performed similar experiments to explore how diploid yeast adapt to the mutator phenotype. We first evolved cells with homozygous mutations a

SUBMITTER: Tracy MA 

PROVIDER: S-EPMC7404223 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature