Leptin gene polymorphism and its association with growth traits in native kil goats

In this study, it was aimed to identify the polymorphism of leptin gene and to determine whether there is a difference between genotypes in terms of growth characteristics of kids. The animal material of the study consisted of 155 kids sampled from different farms. The growth characteristics of the kids were observed from birth to 5.5 months of age. DNA was obtained from blood samples taken from kids at the age of 3.5 months. Subsequently, the 412 bp length region in the Exon 1 region of the leptin gene was amplified by PCR technique using the primer pair specific for that region. In order to reveal the nucleotide polymorphism in the region amplified by PCR, RFLP method was applied and PCR products were cut with NmuCI (Tsp45I) restriction enzyme. Genotypes of the individuals were determined from the band profiles obtained by separating the DNA fragments formed after enzyme cutting by agarose gel electrophoresis. Then, genotype and growth performance data of kids were analyzed by statistical methods and findings were summarized. In the sample of 155 individuals, no CC genotype was detected, 150 individuals were identified as TT and the remaining 5 individuals were identified as TC genotypes. The frequencies of TT, TC and CC genotypes were 0.967, 0.033 and 0.000, respectively. Allele frequencies for T and C were 0.984 and 0.016, respectively. Genotype and allele frequencies were similar for Aydın and Denizli provinces. In terms of the SNP examined, the Kıl goat population was found to be in Hardy-Weinberg equilibrium. Although not statistically significant, the average of TT genotypes was significantly higher than the TC genotypes in terms of all of the growth characteristics of the kids examined (birth weight, live weights at 3.5 and 5.5 months of age, average daily gain for two different periods). The high performance finding of TT genotypes relative to TC genotypes in terms of growth characteristics necessitates further detailed studies based on DNA sequencing of the entire leptin gene and its assosiations with growth data in a much larger animal material.