Claudia Bank

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One of the most controversial questions in evolutionary biology is the role of
adaptation in molecular evolution. After decades of debate between
selectionists and neutralists, new high-throughput methods are beginning to
illuminate the full distribution of fitness effects (DFE) of new mutations. Here,
we shed light on the adaptive potential in Saccharomyces cerevisiae by
presenting systematic high-throughput fitness measurements for hundreds of
engineered mutations in a region of the heat-shock protein Hsp90. We obtain
data sets that allow for the evaluation of fitness consequences of the same
mutations in different environments, and on different genetic backgrounds.
We demonstrate that the change in the DFE upon environmental challenges is
largely consistent with expectations derived from Fisher’s geometric model.
Furthermore, we observe intragenic epistasis to be ubiquitous, which
suggests a concave shape of the underlying local fitness landscape.

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EPFL Lausanne
Institute for Genetics, Seminar Room 0.46
Contact: not specified