ASSOCIATION OF DPP6 GENE POLYMORPHISM WITH PHENOTYPIC TRAITS IN RUSSIAN MEAT MERINO SHEEP BREED

Abstract

The introduction of molecular genetic methods into modern sheep breeding opens up new opportunities for improving the meat qualities of Russian breeds. One of the promising directions is the search for and validation of new molecular markers suitable for marker-assisted selection, based on the identification of single nucleotide polymorphisms associated with productive traits. The aim of the study was to evaluate the confidence level of phenotypic traits differences, which characterize live-animal meat productivity in Russian Meat Merino (RMM) sheep depending on the allelic variants of the rs425802792 polymorphism located in the intronic region of the DPP6 gene. The object of the study was 49 elite-class young rams at 12 months of age, raised under the conditions of the breeding farm “Vtoraya Pyatiletka” (Stavropol Territory). Live-animal evaluation of meat productivity was performed using an extended set of traits, which included both conventional traits (live weight, average daily gain, height at the withers and hips, width of loin, chest width and depth) and additional measurements – shoulder, forearm, and thigh girth – providing a more detailed characterization of muscle development in the limbs. Genotyping was carried out using the Ovine Infinium HD BeadChip 600K. The significance of differences between young ram groups of different genotypes was determined using Student’s test. It was established that carriers of the alternative allele for the rs425802792 substitution significantly outperform homozygous animals for the reference allele in a number of traits, characterizing live-animal meat productivity. In particular, live weight at 12 months was higher by 5,71%, thigh girth by 6.68%, and chest width by 9,70%. A set of the obtained results suggests that DPP6 can be considered as a candidate gene involved in the regulation of sheep growth and development, and that the identified polymorphism may serve as a potential marker for marker-assisted selection, which is aimed at improving meat qualities in RMM sheep. Further research will focus on validating the discovered association on expanded samples, as well as studying the complete sequence of the DPP6 gene using sequencing methods to identify mutations that affect the functional activity of the gene.