Association of polymorphic variants in MSTN, PRL, and DRD2 genes with intensity of young animal growth in Pushkin breed chickens

Polymorphic variants in the myostatin, prolactin, and D2 dopamine receptor genes were analyzed in Pushkin breed chickens (n = 231). The rs313744840 single nucleotide polymorphism was studied in the myostatin gene by means of the PCR–RFLP method. The cocks with different genotypes did not differ from each other by the live weight. Chickens with AA genotype were found to be significantly larger than their coevals with AG and GG genotypes at the age of 49 days (P < 0.01). Polymorphism based on the insertion–deletion of a small gene region (indel-polymorphism) was considered in the prolactin and D2 dopamine receptor genes. Differences by the prolactin gene were observed at 7 days of age. The cocks homozygous by the DD deletion were significantly larger than heterozygous ID coevals (P < 0.05). The II cocks significantly differed by the D2 dopamine receptor gene from heterozygous ID coevals by the live weight at 49 and 110 days. In chickens, II homozygotes by the mutation in the D2 dopamine receptor gene were larger than coevals at 7 days, while they had a lower live weight at 110 days (P < 0.05).