Refining the genomic profiles of North African sheep breeds through meta-analysis of worldwide genomic SNP data

Abstract

We revealed asubstantial enrichment of the gene pool between the north and south shores of the Mediterranean Sea, which corroborates the importance of the maritime route in the history of livestock. The genetic structure of North African breeds mirrors the differential composition of genetic backgrounds following the breed history. Indeed, Maghrebin sheep stocks constitute a geographically and historically coherent unit with any breed-level genetic distinctness among them due to considerable gene flow. We detected a broad east-west pattern describing the most important trend in NA fat-tailed populations, exhibited by the genetic closeness of Egyptian and Libyan fat-tailed sheep to Middle Eastern breeds rather than Maghrebin ones. A Bayesian F_ST scan analysis revealed a set of genes with potentially key adaptive roles in lipid metabolism (<i>BMP2, PDGFD VEGFA, TBX15,</i> and <i>WARS2</i>), coat pigmentation (<i>SOX10, PICK1, PDGFRA, MC1R,</i> and <i>MTIF</i>) and horn morphology <i>RXFP2</i>) in Tunisian sheep. The local ancestry method detected a Merino signature in Tunisian Noire de Thibar sheep near the <i>SULF1</i>gene introgressed by Merino's European breeds. This study will contribute to the general picture of worldwide sheep genetic diversity.