Evaluation of genetic diversity of cattle by the ghrelin gene (GHRL)

Abstract

The aim of this study was to assess the population-genetic structure and parameters of genetic biodiversity at the polymorphic locus g.4491A>G (A375G) of the GHRL gene in cattle of the Tatarstan type of the Kholmogor breed. Ghrelin, encoded by the GHRL gene, plays a key role in regulating appetite, energy metabolism, growth, and dairy productivity, making it a promising marker for breeding. Blood samples from 91 cows served as the material for DNA testing. Genotyping was performed using PCRRFLP with the BstKT I restriction endonuclease. As a result, three genotypes were identified: AA (9.9%), GA (52.7%), and GG (37.4%). The frequency of allele A was 0.363, and that of allele G was 0.637. Population-genetic analysis showed that the studied population is in a state of HardyWeinberg equilibrium, with a predominance of heterozygous genotypes observed, and the polymorphism information content (PIC) characterizes the locus as moderately polymorphic and informative for breeding programs. A comparative analysis with literature data revealed significant interbreed and geographical variability in the frequencies of the GHRL gene. The obtained results emphasize the importance of considering the genetic specificity of local breeds and confirm the potential of using GHRL gene polymorphism as a molecular-genetic marker to enhance the efficiency of cattle breeding. The study was carried out within the framework of the state assignment, registration number 125031003428-9.