Genomic assessment of local sheep breeds is relevant to the reconstruction of post-domestication migrations and to filling in gaps in the developmental history and contemporary phylogeographic-differentiation patterns in Eurasia. In this study, we aimed to reveal possible genetic relationships between local sheep breeds in Russia and the Persian Highlands (Iran) based on high-density SNP genotypes. All samples (n = 395) from 11 Iranian and 10 Russian sheep breeds were genotyped by using the Ovine Infinium HD BeadChip (Illumina, San Diego, CA, USA). Principal Component Analysis, maximum-likelihood assessment, and Neighbor-Net graph analysis demonstrated a clear differentiation between Russian sheep breeds of European ancestry from the Iranian local cluster and Russian breeds of Asian origin. Admixture analysis revealed a shared ancestral background, which was detected in several Iranian-local and Russian-local fat-tailed coarse-wool sheep breeds. Our findings contribute to a better understanding of the pattern of historic admixture, which is present in the genomes of many Eurasian sheep breeds.
