Characteristics of sheep in the Near Arctic region by microsatellites and reproductive abilities

Abstract

The microsatellites polymorphism was analyzed in ewe lambs obtained from intra-breed mating of the Pechora semifine-wool sheep and their littermates from crossing with the Kuibyshev rams. Genotyping of the population by STR loci was performed using the COrDIS Sheep reagent kit recommended by the International Society of Animal Genetics (ISAG). The age of the beginning of reproduction, fertility, milk yield, safety and growth intensity of the litter up to three months of age were taken into account in the ewe lambs. In the group of the Pechora sheep sows 74 alleles were detected, and 81 alleles were detected in the crossbred ones. INRA005 and INRA023 loci were the most polymorphic in both groups, while ETH152 was the least polymorphic. The mean genetic distance between the groups for the 12 STR loci was 0.019 ± 0.003. Pechora sheep (P) and their litters with the Kuibyshev rams (1/2  P + 1/2 K) differed significantly in the frequencies of some STR loci genes. Thus, the INRA023212 allele was found with a frequency of 0.174 in the group of P ewes and was absent in the 1/2 P + 1/2 K group, while the INRA172126 allele was found with a frequency of 0.326 and 0.122, respectively. The mean Fis values in both groups were close to zero. The groups did not differ significantly in the main genetic-population parameters. However, some advantage of the Pechora ewe sows in comparison with the crossbred sheep 1/2 P + 1/2 K on selective traits, apparently, is due to a higher genetic contribution to their heredity of the indigenous northern short-tailed sheep. According to the results of the study, it can be assumed that the age of onset of reproduction of the ewe lambs is related to the level of their heterozygosity for STR loci.