GENETIC CHARACTERISTICS OF THE YAKUT HORSE YANA TYPE

The aim of the study is to assess genetic variability in the population of Yakut horses of the Yana intrabreed type using an extended panel of STR loci, as well as to study the polymorphism of the ASIP, MC1R and STX17 genes that control the characteristics of hair pigmentation. The total number of animals examined was 55. Horses were tested using 25 autosomal STR loci (AHT4, AHT5, ASB2, ASB17, ASB23, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG6, HTG7, HTG10, TKY279, TKY287, TKY321, TKY343, TKY344, TKY294, TKY325, TKY333, TKY341, TKY394, VHL20) and one locus located on the X chromosome (LEX3). Analysis of the genetic structure of the Yana horse population by STR loci showed a high level of genetic variability. The total number of alleles found in 26 studied loci was 208, of which 67 alleles were rare. The average number of effective alleles was 4.69 per locus. The average values of expected (He) and observed (Ho) heterozygosity, taking into account the 25 studied autosomal loci, were 0.762 and 0.761, respectively. A study of the polymorphism of genes controlling hair pigmentation showed that the frequency of the mutant variant of the ASIP gene in the group of Yana horses was 0.500, the frequency of the mutant variant of the MC1R gene was 0.327. The dominant mutation of the STX17 gene, associated with the gray phenotype, was found in 56.36 % of the tested animals. Taking into account the results of testing for 3 genes controlling pigmentation, 14 different genotype variants were identified in the studied population.