Sasha Khristich

Sasha (publishes as Alexandra Khristich) is a Postdoctoral Fellow in the Petrov Lab (2021-now). During her PhD with Sergei Mirkin at Tufts she discovered a novel mechanism by which repetitive DNA sequences change their length. Having spent several years studying how DNA sequences mutate on the molecular level, she became interested in how mutations shape species’ evolutionary trajectories. As a postdoc in the Petrov Lab, she is pursuing two projects related to this question. In one project, she is focusing on the evolutionary meaning of various adaptive mutations using baker’s yeast as a model organism. She is measuring the phenotypes of adaptive mutations in order to understand the mechanism by which mechanism directional selection creates a wide phenotypic diversity. In her other project Sasha is measuring mutation rate of different Saccharomyces cerevisiae strains to understand if the mutation rate itself is an evolvable trait.