Study the Leptin Gene Polymorphism and its Relationship with a Number of Carcass Traits in Iraqi Sheep

Abstract

The study was conducted on a group of local sheep in the Suq Al-Shuyukh district, south of Thi-Qar province. It included the slaughter of 48 animals in a butcher shop. The aim of the study was to determine the genotypes of the leptin gene using nucleotide sequencing technology and its relationship with a number of carcass traits in local sheep. Through the nucleotide sequencing of the targeted genetic segment of the leptin gene (471 bp) in local sheep, it was found that there was one mutation at position 311 within the studied region of the leptin gene. This mutation resulted in the change of the nitrogen base G to T, leading to the substitution of the amino acid valine with leucine. The variation (mutation) occurred in exon 3 at amino acid position 95. Therefore, this mutation is considered a missense mutation and appeared in three genetic patterns: GG, GT, and TT, with distribution ratios as follows: the highest distribution was for the hybrid genotype (GT), followed by the genotype GG and TT. Most of the studied traits did not show significant differences between the three genotypes of the targeted genetic segment of the leptin gene, except for the significant superiority (P<0.01) of sheep with the hybrid genotype (GT) in the carcass diameter trait and the significant superiority (P<0.01) of sheep with the mutant genotype (TT) in the meat pH trait.