Genetic variation in the bovine genome : signatures of selection and demographic history

Abstract

Domestication, and its associated environmental and demographic changes, undoubtedly brought new challenges to early domesticates, such as cattle. One of the most important would have been the emergence of new disease challenges and changes in disease epidemiology. If, as a result, selection acted on genes conferring increased disease resistance, for example, then signatures of this selection should be evident in the genomes of modern cattle. Cattle are economically important all over the world and losses due to disease are significant, particularly in the developing world. Identifying putative sites of selection helps to drive new discoveries by directing future work to the regions with most potential impact. This may be done "blind", using a genome-wide scan for unusual loci, or by targeting specific candidate genes based on prior knowledge. Here, both approaches are taken. By examining diversity at a particular locus in the context of wider genomic diversity, it should be possible to distinguish the signature of selection from the effects of demographic history.