A Genetic Incompatibility Accelerates Adaptation in Yeast

摘要: During mismatch repair (MMR) MSH proteins bind to mismatches that form as the result of DNA replication errors and recruit MLH factors such Mlh1-Pms1 initiate excision steps. Previously, we identified a negative epistatic interaction involving naturally occurring polymorphisms in MLH1 PMS1 genes baker’s yeast. Here hypothesize mutagenic state resulting from this increases likelihood obtaining beneficial mutations can promote adaptation stress conditions. We tested by stressing yeast strains bearing (incompatible) non-mutagenic (compatible) genotypes. Our data show incompatible populations adapted more rapidly without an apparent fitness cost high salt stress. The advantage was rapid but disappeared over time. gains both compatible were due primarily PMR1 appeared earlier evolving populations. These demonstrate reversible role (by mating) for genetic incompatibilities accelerating eukaryotes. They also provide approach link experimental studies observational population genomics.