ASSESSMENT OF GENETIC DIVERSITY IN POPULATIONS OF DAIRY CATTLE BREEDS OF UKRAINIAN SELECTION USING MICROSATELET MARKERS

The article presents the results of a study of the genetic and population structure in herds of Ukrainian Black-and-White and Red-and-White dairy breeds kept in the Kharkiv region (DPDH “Hontarivka”). The analysis of genetic variability in the experimental groups of animals was carried out using 10 microsatellite loci recommended by FAO-ISAG: ETH225, BM2113, ETH3, BM1818, BM1824, ILSTS006, INRA023, TAGLA053, TAGLA12, ETH10. The amplification products were separated in native polyacrylamide gels of different concentrations (5 – 8 %). All studied loci were found to be polymorphic. The number of detected alleles per locus ranged from 4 to 8 (on average 5 alleles per locus) the size of which ranged from 115 bp (ETH3) to 307 bp (ILSTS006). The vast majority of studied loci belong to informatively valuable markers (PIC > 0.5). The most polymorphic loci for both breeds were TGLA053 (8 alleles), BM2113 (6) and ETH3(6). The main population genetic parameters were calculated for the studied loci. The highest values of heterozygosity indices (He) and effective number of alleles (ne) were characteristic of the BM2113 locus (He=0.80-0.81, ne=5.1-5.3). The minimum values of expected heterozygosity were established for the ETH3 loci (0.53-0.55; Ukrainian Black-and-White and Red-and-White dairy breeds) and BM1818 (0.59, Ukrainian Black-and-White dairy breed). For most microsatellite loci, an equilibrium state between the actual and expected genotype frequencies is characteristic. A probable deviation in the form of a deficit of heterozygotes was established only for the BM1818 locus in both experimental populations (Fis = 0.37; p < 0.05). Changes in the genetic structure of the experimental cattle population (Kharkiv region) were analyzed in comparison with data from previous years of research, other regions, and with data from the initial forms involved in the creation of these breeds. Analysis of genetic changes that occurred during the reproduction of experimental cattle populations indicates a narrowing of genetic variability and the need to control genetic processes in breeding work.