ASSESSMENT OF THE ALLELE POOL OF THE KHOLMOGORY CATTLE BREED WITH USING STR-MARKERS
The crossing with the Holstein bulls is widely used to improve the productive traits of the Kholmogory cattle breed, characterized by unpretentiousness and high adaptive qualities. This process might result in a loss of the original gene pool of the Kholmogory cattle breed without assessment by DNA markers. In this regard, our aim was to perform genetic assessment of the allele pool of the populations of the Kholmogory cattle breed using STR markers. Sample collection included 289 heads of the Kholmogory cattle, including Old Kamchatka (ST KAM, n=68) and Old Komi groups (STKOMI, n=24), Northern (KHOLM, n = 19), Tatar (TAT, n=53) and Pechora (PECH, n=125) types. The STR profiles of the animals from the Holstein breed (GOLSH) were used as a comparison group. The number of informative alleles varied from 4.36 in sT_KOMI to 4.91 in KHOLM and PECH with the average value for the Kholmogory breed in 4.67 in comparison with 4.55 in the Holstein breed. The effective number of alleles in the Kholmogory breed slightly exceeded the value of this indicator in the Holstein breed (3.87 and 3.81 alleles, respectively). All populations of the Kholmogory breed were characterized by a slight excess of heterozygotes. The minimum value of FST (0.016) was recorded between the TAT and CT_KAM groups, while the maximum was observed between the populations of PECH and GOLSH (FST=0.041). The Principal Coordinates Analysis (PCoA), the structure of the dendrogram and cluster analysis revealed the genetic similarities between PECH and ST_KOMI, as well as close genetic relationships between TAT and GOLSH. In addition, the animals of the PECH group were characterized by the presence of the genetic background that was absent in other populations of the Kholmogory cattle. Thus, the results indicate that, along with the significant genetic influence of the Holstein cattle, the original gene pool of the Kholmogory cattle breed has not been lost, which is an important factor for the development of effective conservation programs for this breed.