Genetic structure on the GPX-1 gene in populations of Holstin cattle of domestic and foreign selection

The article presents the data of DNA testing of Holstein cattle by the GPX-1 gene. The structure of the Tatarstan population was studied in comparison with world experience. Genotyping was carried out by PCR-RFLP followed by electrophoretic separation in agarose gel in the presence of ethidium bromide. In the conditions of the Dairy farm “named Lenin” and CF “Mukhametshin Z.Z.” carried out the identification of cattle by the locus of GPX-1 - BsC4 I, assessed the genetic equilibrium and structure of the populations. As a result of gene diagnostics, two alleles and three genotypes were identified. In domestic Holstein herd the frequency of occurrence of alleles C and T was 0.502 and 0.498; genotypes CC, TC and TT -20.0, 60.3, и 19.7 %, respectively. In foreign Holstein herd the frequency of occurrence of alleles C and T was 0.513 and 0.487; genotypes CC, TC and TT - 23.0, 57.7 and 20.3 %, respectively. Chi-quad testing showed that the studied populations were in Hardy-Weinberg disequilibrium. The difference in the genetic structure of the populations of domestic and foreign breeding can be caused by the use of sperm production of bulls of different lines.