The Evolution of Mutation Rate in Yeast

10:00am - 11:00am
Zoom ID : 960 0128 8135 Passcode: 792659


What determines the rate (μ) and molecular spectrum of mutation is a fundamental question.  The prevailing hypothesis asserts that natural selection against deleterious mutations has pushed μ to the minimum achievable in the presence of genetic drift, or the drift barrier.  Here we show that, contrasting this hypothesis, μ substantially exceeds the drift barrier in diverse organisms.  Random mutation accumulation (MA) in yeast frequently reduces μ, and deleting the newly discovered mutator gene PSP2 nearly halves μ.  These results, along with a comparison between the MA and natural yeast strains, demonstrate that μ is maintained above the drift barrier by stabilizing selection.  Similar comparisons show that the mutation spectrum such as the universal AT mutational bias is not intrinsic but has been selectively preserved.  These findings blur the separation of mutation from selection as distinct evolutionary forces but open the door to alleviating mutagenesis in various organisms by genome editing.


Event Format
Speakers / Performers:
Haoxuan LIU
Department of Ecology and Evolutionary Biology, University of Michigan



Dr. Haoxuan Liu gets his Ph.D. at Nanjing University in 2017, and is now a postdoc in the department of Ecology and Evolutionary Biology at the University of Michigan. His research interest covers a broad span in relation to genetics and evolution. In the past his has focused on three specific areas: (1) computational evolutionary genomics; (2) construction of high-resolution recombination maps; (3) the evolution of mutation rate.

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