Genetic structure of Tatar and Yakut horse breeds based on blood polymorphic proteins

This study presents the results of an analysis of allele pool of Tatar horse breed in comparison with the allele pool of Yakut breed. The obtained data can be used in further breeding work. The study established that local horse breeds have a wide spectrum of alleles for polymorphic blood proteins and a high level of genetic diversity. Transferrin locus is determined by five alleles in the studied horse breeds: F, D, R, H and O, while the albumin locus was weakly polymorphic and represented by only two alleles: A and B. Genetic analysis of Tatar and Yakut horses, respectively, identified 15 genotypes out of 15 possible allelic combinations. The most frequent allele in both populations was F allele. Its frequency in Yakut horse breed was significantly higher than that in Tatar horses by 0.134 (p < 0.05), indicating significant differentiation at this locus. In contrast, the O allele of transferrin was minimally represented: 0.053 in Tatar horse breed, while in Yakut breed it was 0.030, corresponding to a 1.77-fold decrease. This allele indicates statistical similarity between the two breeds for this polymorphism. In the polymorphic blood systems of the two breeds, the polymorphism level averaged 2.441, a result considered high for local horse breeds. Horses of Tatar breed are characterized by a high degree of heterozygosity, averaging 0.597, which is 0.191 higher than the same indicator in Yakut breed. Consequently, distinct interbreed differences in allele frequencies, heterozygosity levels and the number of effective alleles are evident in Tatar and Yakut horse breeds’ blood polymorphic protein loci, indicating a certain genetic distance between the studied horse breeds.