Adaptation by Loss of Heterozygosity in Saccharomyces cerevisiae Clones Under Divergent Selection.

ABSTRACT: Loss of heterozygosity (LOH) is observed during vegetative growth and reproduction of diploid genotypes through mitotic crossovers, aneuploidy caused by nondisjunction, and gene conversion. We aimed to test the role that LOH plays during adaptation of two highly heterozygous Saccharomyces cerevisiae genotypes to multiple environments over a short time span in the laboratory. We hypothesized that adaptation would be observed through parallel LOH events across replicate populations. Using genome resequencing of 70 clones, we found that LOH was widespread with 5.2 LOH events per clone after ∼500 generations. The most common mode of LOH was gene conversion (51%) followed by crossing over consistent with either break-induced replication or double Holliday junction resolution. There was n

SUBMITTER: James TY 

PROVIDER: S-EPMC6781901 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature