Genomic analysis of hair sheep from West/Central Africa reveals unique genetic diversity and ancestral links to breed formation in the Caribbean

Authors: WIENER, PAM - Roslin Institute; FRIEDRICH, JULIANE - Roslin Institute; MARR, MELISSA - Roslin Institute; SIMO, GUSTAVE - University Of Dschang; TANYA, VINCENT - Collaborator; BALLINGALL, KEITH - The Moredun Group; FLEGONTOV, PAVEL - University Of Ostrava; Rosen, Benjamin; SALLE, GUILLAUME - Inrae; SPANGLER, GORDON - Former ARS Employee; Van Tassell, Curtis; SALAVATI, MAZDAK - Roslin Institute; MEUTCHIEYE, FELIX - University Of Dschang; CLARK, EMILY - Roslin Institute

Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2025
Publication Date: 6/2/2025
Citation: Wiener, P., Friedrich, J., Marr, M., Simo, G., Tanya, V., Ballingall, K., Flegontov, P., Rosen, B.D., Salle, G., Spangler, G., Van Tassell, C.P., Salavati, M., Meutchieye, F., Clark, E. 2025. Genomic analysis of hair sheep from West/Central Africa reveals unique genetic diversity and ancestral links to breed formation in the Caribbean. Molecular Ecology. https://doi.org/10.1111/mec.17796.
DOI: https://doi.org/10.1111/mec.17796

Interpretive Summary: Cameroon sheep are a breed of hair sheep from West/Central Africa. This variety of sheep is popular with small holder farmers in Cameroon because they are adapted to harsh conditions and are fertile breeders. The aim of this study was to compare the Cameroon Blackbelly sheep to other sheep breeds from around the world. We first examined the genetic diversity of the Cameroon Blackbelly sheep in relation to global sheep populations. Using DNA sequencing data, we compared the Cameroon Blackbelly sheep to African sheep, breeds from Europe, and the Barbados Blackbelly breed from the Caribbean. The Cameroon Blackbelly sheep is visually very similar to the Barbados Blackbelly. Results from genetic comparisons showed both West/Central African and European heritages contributed to the Barbados Blackbelly sheep. The findings of our study support the view that sheep were transported from West/Central Africa to the Caribbean as part of the slave trade and European colonization during the 17th century. The tools created in this work also highlight the unique genetic diversity represented by West/Central African sheep, their contribution to global breed development, and the importance of preserving genetic diversity.

Technical Abstract: Cameroon sheep are a domestic breed of hair sheep from West/Central Africa. They are popular with small holder farmers in Cameroon as they are highly resilient to local environmental challenges and are prolific aseasonal breeders. These desirable characteristics have also led to their export across the globe. The aim of this study was to characterise the genetics of the Cameroon Blackbelly sheep in relation to other sheep breeds from across the world and to investigate their relationship to Caribbean hair sheep. We first examined the genetic diversity of the Cameroon Blackbelly sheep relative to global sheep populations using the sheep HapMap dataset and 50K genotypes from Cameroon Blackbelly sheep collected from different geographical locations in Cameroon. Using whole genome sequencing data, we also compared the Cameroon Blackbelly sheep to other African sheep, breeds from Europe and the Barbados Blackbelly breed from the Caribbean, which is phenotypically very similar to Cameroon Blackbelly. Admixture results based on both 50K and WGS data demonstrated both West/Central African and European ancestries for the Barbados Blackbelly sheep. Local Ancestry inference identified several genomic regions (including OAR3, 5, 9 and 19) in Barbados Blackbelly that had high proportions of West/Central African ancestry. The region on OAR3 includes various keratin genes, suggesting that these genes may play a role in the shared coat phenotypes of Barbados Blackbelly and Cameroon Blackbelly. The findings of our study support the view that sheep were transported from West/Central Africa to the Caribbean as part of the slave trade and European colonization during the 17th century. The genomic resources we have generated also highlight the unique genetic diversity represented by West/Central African sheep, their contribution to global breed formation, and the importance of conserving genetic diversity.