Search

Aim. One of the important tasks in solving the problem of improving the efficiency of sheep breeding is the rational use of fodder lands in the North Caucasus and the South of Russia, a significant part of which is located in different natural and climatic conditions. The complexity of solutions lies in insufficient knowledge of the mechanisms of adaptation of farm animals, in particular sheep, to the ecological and geographical features of these regions. The purpose of this research was to study the genetic polymorphism of genes, the degree of genetic variability and immune status in sheep of different breeds, since genetic polymorphism is a measure of its adaptability and the hematopoietic function of blood is the basis of the life of the organism.Material and Methods. The genetic structure of the GH/Hae III, GDF9/AsplEI genes and immune status, was studied by the methods of genetic‐statistical and immune analysis in sheep of different breeds kept in different climatic zones of Dagestan and the Krasnodar Territory.Results. As a result of DNA genotyping of the studied samples of sheep of different breeds, it was found that polymorphism of GH/HaeIII, GDF9/AsplEI genes is represented by three genotype variants: homozygous GH/HaeIIIАА, GH/HaeIIIВВ; GDF9/AsplEIАА, GDF9/AsplEIGG; heterozygous GH/HaeIIIAB; GDF9/AsplEIAG and two alleles: A and B – of the GH/HaeIII gene; A and G – GDF9/AsplEI gene with different frequency of occurrence, respectively.Conclusion. For the first time, genetic variability has been studied in the context of the immune status of sheep populations of different breeds bred in the foothills of the Republic of Dagestan and Krasnodar Territory. The information obtained about the role of the degree of genetic variability and the immune status of sheep of different breeds is answered in the formation of adaptive‐compensatory mechanisms to specific conditions of the breeding environment. A deeper study of the adaptive characteristics of sheep of different breeds for their further improvement allows the use of molecular genetic and hematological methods.

Aim. To study the polymorphism of the genes calpastatin (CAST), somatotropin (GH) and differential growth factor (GDF9) of sheep of the Dagestan mountain breed.Material and Methods. Studies on the genetic typing of Dagestan mountain sheep according to CAST, GH and GDF9 genes were carried out in conditions of distant pasture farming in the Republic of Dagestan by the Genetics and Breeding Laboratory of the Federal Agrarian Scientific Centre of the Republic of Dagestan, an accredited laboratory of immunogenetics and DNA technologies of the All-Russian Research Institute of Sheep and Goat Breeding and a branch of the North Caucasus Federal Scientific Agrarian Centre. These investigations were undertaken by the PCR-RFLP method (polymyrase chain reaction - restriction fragment length polymorphism) on a Tersik four-channel programmable thermal cycler from DNA-Technologia (Russia) using specific primers synthesized in the SYNTHOL research and production laboratory (Moscow).Results. Carrying out PCR-RFLP revealed breed-specific alleles with different frequency of occurrence, which was: in the locus of the CAST gene - allele CASTN - 0.03; allele CASTM - 0.97; at the GH gene locus - GHA allele - 100.0, GHB allele - 0; in the locus of the GDF9 gene - the GDF9A allele - 0.25, the GDF9G allele - 0.75, which determined the frequency of occurrence of the homo- and heterozygous genotypes: CASTNN, CASTMM and CASTNM - 93.0; 0 and 7.0%; GHAA, GHBB and GHAB - 100.0 and 0%; GDF9AA, GDF9GG and GDF9АG- 16.0, 66.0 and 19.0%, respectively.Conclusion. The regularity revealed can be considered as an ecological factor that optimizes the adaptive functions of the sheep's organism, on the one hand, an evolutionary selection process that contributes to the creation of a specific way of genetic structures in the population, on the other. The assumption is made that the information obtained can serve as the beginning of a more in-depth study of the unique gene pool of sheep of the Dagestan rock breed for its further improvement. Variants of genetic marker profiles of parental pairs are proposed for accumulation in breeding herds bred in different ecological-geographical zones and genotypes of carriers of selection-significant genetic structures.

The Dagestan Mountain (DM) cattle breed was established to provide cheese and milk products to mountain dwellers in the specific conditions of the Republic of Dagestan in Southern Russia. Only 650 head of DM cattle were registered in 2020, and their “breed purity” is questionable. We aimed to assess the genetic diversity and population structure of modern DM cattle using short tandem repeat (STR) markers. The sample included 150 animals collected from private owners in Dagestan during a scientific expedition (n = 32) and provided by a gene pool farm (n = 118). An additional 166 samples from other cattle breeds distributed in the breeding zone of DM cattle were used as the comparison groups. The genotypes for the 11 STR loci recommended by ISAG were obtained using a genetic analyzer. We identified a high level of genetic diversity as revealed by allelic richness calculations (Ar = 6.82 vs. 4.38–5.82 in other cattle breeds) and observed heterozygosity indices (uHe = 0.76 vs. 0.65–0.72). Based on the STRUCTURE results, animals with low levels of admixture with other breeds were found within the DM cattle, which can be considered as candidates for use in germplasm conservation programs.