Carcass and commercial cut yield of Santa Ines sheep affected by polymorphisms of the LEP gene

Leptin plays an important role in the metabolism of various tissues, and, therefore, polymorphisms in its LEP gene may be associated with the variation of several phenotypic traits in sheep. This study aimed to identify polymorphisms in LEP from Santa Ines sheep as well as to test its association with carcass traits. A 2045-bp fragment was sequenced, in which 21 polymorphisms were identified. Of these, 9 polymorphisms were identified for the first time in sheep. The g.92501206C > T, g.92501372 G > A and g.92502987delA showed no Hardy-Weinberg equilibrium, while the minor allele frequency ranged from 0.01 (g.92502987delA) to 0.45 (g.92503044 A > G). The g.92501372 G > A influenced the neck weight and neck yield, and the difference between AA and GG were 1.93 kg (neck weight) and 1.47% (neck yield). The g.92501407C > T affected the hot and cold carcass weights, with 1.00 kg and 0.97 kg of differences between TT and CC, respectively. The g.92501543 A > G affected the hot and cold carcass yields, leg yield, and internal carcass length, with 3.17%, 3.03%, 3.12% and 1.83 cm of difference between GG and AA, respectively. Finally, the g.92503024 G > A showed an additive effect on the carcass finishing score, where the genotype AA had a higher score (0.32 points) than GG genotype. Haplotype analysis confirmed some of the effects noted in the single-locus analysis and revealed novel effects for carcass traits. Therefore, it can be concluded that some polymorphisms in the leptin gene can provide information for improvement of the carcass attributes of Santa Ines sheep.