Signatures of selection in four indigenous horse breeds of Iran

Indigenous Iranian horse breeds were evolutionarily affected by natural and artificial selection in distinct phylogeographic clades which shaped their genomes in several unique ways. The aims of this study were to evaluate genetic diversity and genome-wide selection signatures in four indigenous Iranian horse breeds. We evaluated 169 horses from Caspian (n = 21), Turkmen (n = 29), Kurdish (n = 67), and Persian Arabian (n = 52) populations, using genome-wide genotyping data. The contemporary effective population sizes were 59, 98, 102, and 113 for Turkmen, Caspian, Persian Arabian, and Kurdish, respectively. Analysis of population genetic structure classified the north breeds (Caspian and Turkmen) and west/southwest breeds (Persian Arabian and Kurdish) into two phylogeographic clades reflecting their geographic origin. Using a de-correlated composite of multiple selection signals statistics based on pairwise comparisons, we detected a different number of significant SNPs under putative s..., ,