Lecture 27 April: Towards an Understanding of Genome Evolution

Dr David Liberles from the Computational Biology Unit at the University of Bergen will give a talk on large scale comparative genomics, myostatin, and modeling gene duplication and evolution.


Time: Wednesday 27 April, 1015 - 1100
Place: Norwegian University of Life Sciences (UMB) - Ås, Animal Science Building, room H175

David Liberles
David Liberles
Foto: Rein Aasland
As genomes evolve through drift and under divergent selective pressure, gene content, sequence, expression, and function change. A resource, The Adaptive Evolution Database (TAED) has been created to describe this change, indexed phylogenetically. The initial characterization of genomic data in the database is gene sequence evolution, with statistical measures like the ratio of nonsynonymous to synonymous nucleotide substitution rates (Ka/Ks) as a measure of selective pressure. A subset of genes under lineage-specific positive selective pressure (potentially with changed functions) is being characterized in more detail. One example, myostatin, a negative regulator of skeletal muscle appears to have been under strong positive selective pressure early in the divergence of ruminant artiodactyls and this will be described in more detail.

Finally, a simple physical framework has been established to characterize the evolution of proteins models that fold and bind to substrates, after gene duplication events. This framework has been used to model duplicate gene retention rates through subfunctionalization and neofunctionalization, both alone and together, to understand the process of functional divergence after gene duplication and its role in genome evolution. The model is currently being extended to characterize the fold distribution in genomes using principles from physical chemistry and population genetics. Ultimately, we hope to tie this together into a greater understanding of how genes and genomes evolve and what this means for organismal phenotypes.

Fore more information on Dr. Liberles, his work and his research group, please see http://www.cbu.uib.no/research/liberles/