Mutation, duplication, and selection in mammalian genomes

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 i...

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Detalles Bibliográficos
Autor: Laurie, Steven
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/120514
Acceso en línea:http://hdl.handle.net/10803/120514
Access Level:acceso abierto
Palabra clave:evolution
gene
protein
mammal
human
insertion
deletion
substitution
duplication
indels
evolució
gen
proteïna
mamífer
humà
inserció
deleció
substitució
duplicació
575
Descripción
Sumario: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 look 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 lead support to the role of neofuntionalisation following gene duplication.