Polymorphisms at Ovine Leptin Gene and its Association with Growth And Carcass Traits in Three Iranian Sheep Breeds

This study aimed to evaluate the genotype and gene frequencies of Leptin Gene (LEP) and its association with growth and carcass traits in three Iranian sheep breeds. The breeds included Chaal، Zandi and Zel. Genomic DNA extracted from the whole blood samples and PCR was carried out in order to amplify 260 bp fragment of the exon 2 and part of intron 2. Polymorphisms were detected using single strand conformation polymorphism (SSCP) technique. Frequencies of A and G allele were 0. 76، 0. 24، 0. 85، 0. 15 and 0. 82، 0. 18 in the Chaal، Zandi and Zel breeds، respectively. Chi-Square test confirmed Hardy-Weinberg equilibrium for the LEP loci. Average observed heterozygousity of the LEP locus was slightly low. The PCR fragments were sequenced. Comparison of the sequences of the results showed a single nucleotide polymorphisms A→G transition at the 113th bp position of intron 2 of LEP gene. In the Chaal breed، the A113G SNP is associated with increase of fat-tail and total body fat. In the Zel breed، the A113G SNP is associated with increase of fat-tail and reduction of lean meat of the carcass traits. Therefore، there is significant association between A113G SNP and carcass traits in Iranian sheep breeds.