July 25th, 2013

Thesis defence of Steve Laurie "Mutation, duplication, and selection in mammalian genomes"

On July 25th, Steve Laurie, member of the Evolutionary Genomics Group of GRIB (IMIM-UPF) will defend his thesis at 11:00 at Aula Room of PRBB.


This thesis comprises comparative genomics analyses primarily focussing on the evolution of mammalian proteins. We concentrate on three species of direct relevance as model organisms, for which high quality genome sequences are available, and human. Having previously investigated protein evolution in terms of substitution rates, here we explored less well studied insertions and deletions (indels). We show that indel and substitution frequencies are correlated at the level of protein sequence, and that indels, and in particular insertions, are elevated in regions of low-complexity and repetitive sequence. Furthermore we observe that selection acts more strongly against the incorporation of insertions than deletions in coding sequence. We also examine in detail the process of evolution following gene duplication in rodents. We show that in general there is a marked increase in evolutionary rate following duplication, which is restricted to the new copy. We find evidence that this increase is sometimes driven by positive selection, and often accompanied by changes in tissue expression profile. These results lend support to the role of neofuntionalisation following gene duplication.

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