Whole genome structural analysis of Caribbean hair sheep reveals quantitative link to West African ancestry

Authors: Spangler, Gordon; Rosen, Benjamin - Ben; IIORI, MOSES - University Of Nottingham; HANOTTE, OLIVIER - University Of Nottingham; KIM, EUI-SOO - Recombinetics, Inc; SONSTEGARD, TAD - Former ARS Employee; Burke, Joan; MORGAN, JAMES - Katahdin Hair Sheep International; NOTTER, DAVID - Virginia Tech; Van Tassell, Curtis - Curt

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2017
Publication Date: 6/29/2017
Publication URL: http://handle.nal.usda.gov/10113/5931470
Citation: Spangler, G.L., Rosen, B.D., Iiori, M.B., Hanotte, O., Kim, E.S., Sonstegard, T.S., Burke, J.M., Morgan, J.L., Notter, D.R., Van Tassell, C.P. 2017. Whole genome structural analysis of Caribbean hair sheep reveals quantitative link to West African ancestry. PLoS One. 12(6):e0179021.

Interpretive Summary: Hair sheep of Caribbean origin have become an important part of the U.S. sheep industry. Lack of wool eliminates a number of health concerns and drastically reduces the cost of production. More importantly, Caribbean hair sheep demonstrate robust performance even in the presence of drug resistant parasites. Despite the growing importance of hair sheep in the Americas their genetic origins have remained speculative. Prior to this report no genetic studies were able to identify a unique geographical origin of hair sheep in the New World. Our study clarifies the African and European ancestry of Caribbean hair sheep. We conducted a detailed genetic analysis on four breeds of Caribbean Hair sheep to clarify the exact origins of these breeds in the Americas. Using samples representing Africa and Europe we establish an objective measure indicating Caribbean hair sheep are derived from Iberian and West African imports brought to the region during the Colonial Period. More specifically, Caribbean Hair sheep are a result of the introduction of West African traits into climate adjusted sheep of Iberian descent, such as the Spanish Churra These results are will contribute to discovery of more detailed exploration of trait loci, as well as provide valuable information for sheep breeders in the face of economic change, global warming, and the increasing pressure of drug resistant parasites.

Technical Abstract: Hair sheep of Caribbean origin have become an important part of the U.S. sheep industry. Lack of wool eliminates a number of health concerns and drastically reduces the cost of production. More importantly, Caribbean hair sheep demonstrate robust performance even in the presence of drug resistant gastrointestinal nematodes, a rising concern to the industry. Despite the growing importance of hair sheep in the Americas their genetic origins have remained speculative. Prior to this report no genetic studies were able to identify a unique geographical origin of hair sheep in the New World. Our study clarifies the African and European ancestry of Caribbean hair sheep. Whole genome structural analysis was conducted on four established breeds of hair sheep from the Caribbean region. Using breeds representing Africa and Europe we establish an objective measure indicating Caribbean hair sheep are derived from Iberian and West African origins. Caribbean hair sheep result from West African introgression into established ecotypes of Iberian descent. Genotypes from 47,750 autosomal single nucleotide polymorphism markers scored in 290 animals were used to characterize the population structure of the St Croix, Barbados Blackbelly, Morada Nova, and Santa Ines. Principal components, admixture, and phylogenetic analyses results correlate with historical patterns of colonization and trade. These patterns support co-migration of these sheep with humans.