Analysis of polymorphic variants of MSTN, CAST, PRLR genes associations with economically useful qualities of vyatka breed horses

The relationship of polymorphic variants of MSTN, CAST, PRLR genes with working qualities and body types of Vyatka horses was studied. The purpose of the research is to assess the genetic and breeding potential of the Vyatka breed horses, as well as to study the relationship between the MSTN, CAST, PRLR genotypes and the economically useful qualities of horses. The method of DNA extraction from Vyatka horse hair follicles using ExtraGene DNA Prep. was applied. When scanning the mutations in the loci MSTN (n=43), CAST (n=41) and PRLR (n=41), DNA amplification the method of allele-specific PCR was performed. The frequency of alleles and genotypes was calculated using MS Excel 10. As a result of research, the dependence of Vyatka horses working qualities on the frequency of occurrence of myostatin MSTN alleles (g.66493737 T>C) was noted. The horses with a higher occurrence of the MSTN/C allele have more productive movements than the individuals with the T/T genotype typical for aborigines. Vyatka horses with the T/T genotype are more versatile, and also show better results in sledding, while the horses with the T/C genotype are better under saddle. The horses with the T/T genotype have the highest bony index but the lowest massiveness index. The MSTN T/T (0.581) homozygous genotype for the "wild" allele predominates in Vyatka horses. A relation ship between body types and the calpastatin gene (CAST) has been revealed for the first time in horse breeding. The horses with the G/A genotype turned out to be the most massive and bony, the horses with the A/A genotype were lighter, the highest frequency of occurrence of the CAST G/A genotype (0.463) was noted, the CAST G/G genotype is rare in the breed (0.171). A relationship between the frequency of occurrence of prolactin receptor genes (PRLR) and body types of horses was not found. The frequency of occurrence of PRLR C/C (0.366) and PRLR G/C (0.390) genotypes is approximately identical, the PRLR G/G genotype is less common (0.244). The study of genes associated with economically useful qualities in all breeding stallions will enable to conduct more efficient breeding, using the desired genotypes, which is important for small breeds.