The Sheep Genomes Database Used to Identify Signatures of Selection

Whole genome sequencing promises to accelerate our ability to identify the genetic basis of phenotypic variation in domestic animals, and to understand aspects of their population history. The International Sheep Genomics Consortium (ISGC) has initiated establishment of the Sheep Genomes Database, a public repository designed to serve as a data portal and coordination point for the analysis of ovine whole genome sequences. To begin populating the database, 73 sheep from over 40 divergent breeds were sequenced to an average depth of 10-fold coverage per animal. Following variant calling which detected ~ 20 million SNP, 137 genomic regions were identified with significantly reduced levels of heterozygosity that are likely to have experienced selection. A comparison of these regions against a completed SNP50 based scan for selection sweeps revealed a number of overlaps including at the RXFP2 gene associated with poll – horn and pigmentation genes including MSRB3, MITF and ASIP. Strong selection sweeps were also detected surrounding genes involved in wool growth and development (EDAR, HOXC13), body mass, height and early maturation  (LIN28B, IGFBP4, PPP2R2A) and disease resistance (MHC, SOCS1). These results advance our understanding of the genetic history of this important livestock species. The attributes of the Sheep Genomes Database will be presented to foster awareness and utilisation across the research community.