Pigs were RFLP-genotyped for the leptin gene (mutation T3469C). The study examined 185 boars of four breeds (Duroc, Large White, Landrace, and Yorkshire) from the Belgorod region of Russia. In all breeds, the wild T allele is the most frequent, which is responsible for leaner meat and lower fat content. The highest frequency of the C mutant allele was found in the Large White (0.223), and the lowest – in Yorkshire pigs (0.011). At the same time, no homozygotes were found for this allele in Landrace and Yorkshire meat breeds. In general, the allele frequencies of the studied breeds correspond to the frequencies of European and Canadian selection. According to the χ² test, all studied breeds are in a state of genetic equilibrium according to Hardy-Weinberg.

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