Plant & Animal Genomes XVII Conference Plant & Animal Genomes XVII ConferenceJanuary 10-14, 2009
Town & Country Convention Center
San Diego, CA
James W Kijas1 , on behalf of the ISGC2
Understanding the population structure of sheep and the polymorphic component of the ovine genome is important to achieving genetic gain through genome-wide association studies and the application of genomic selection. To evaluate the level of genetic diversity both within and between breeds, the International Sheep Genomics Consortium genotyped 23 breeds of domestic sheep and two wild species using a panel of 1536 SNP. Cluster analysis and the partitioning of genetic variation demonstrated sheep breeds have a weak phylogeographic structure which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. For example, African and Asian breeds clustered separately from animals of European origin, which were collected in Australia, New Zealand, Europe and North America. A much larger experiment has been launched to assign the ancestral status of SNP, evaluate linkage disequilibrium and search for the molecular signatures of selection within the sheep genome. In excess of 2500 sheep from 50 breeds have been genotyped using the iSelect™ SNP BeadChip. This provides a comprehensive view of the degree of polymorphism across the sheep genome and an understanding of the phylogenetic history of the species based on statistical analysis of molecular genetic variation.