The Genetic Structure of the Russian Horse Breed

A total of 166 horses of the Russian Riding breed were studied using 17 microsatellite loci recommended by ISAG. Microsatellite polymorphism data of 34 European breeds (7874 individuals) were used for comparative analysis of genetic diversity and modern clustering. The Russian Riding horse has high values of allele richness, 5.4 alleles per microsatellite locus. In total, 122 alleles were found in the breed, including the private allele 14 at the HTG7 locus. The population genetic structure of the Russian riding, Arabian, Akhal-Teke, German riding, and purebred riding breeds has been described. Clustering of horse breeds on a circular UPGMA dendrogram revealed six main clusters. The Russian riding horse grouped with the German and purebred English horses in the PCA analysis. Breeds were divided into three populations in STRUCTURE ( K = 3): (1) Arabian, (2) Russian Riding, Akhal-Teke, and Thoroughbred Riding, (3) German Half-Bred. Differentiation analysis between breeds using the F st method showed the greatest values (differences) between Akhal-Teke horses and all other breeds. The smallest value ( F st = 0.22) between the Russian riding and German riding breed. Pairwise differences between breeds were significant ( p -value < 0.001).