Study on the relationship between leptin gene polymorphism and growth traits and its effect on breeding values in Moghani Sheep

In this research for identification of polymorphism in leptin gene in sheep population of Moghani breed, 90 heads were randomly blooded. Genomic DNA was extracted from blood samples and a piece including 471 bp from the part of exon 3 leptin gene was amplified with using PCR-SSCP. Five banding patterns AA, AB, AC, BC and CC were obtained with frequencies of 0.2, 0.25, 0.3, 0.1 and 0.15 respectively. The frequencies of A, B and C alleles were calculated as 0.475, 0.175 and 0.35 respectively. The Chi-Square test showed no significant deviation (P>0.05) from Hardy-Weinberg equilibrium for this locus in studied population. AC genotype was associated with highest birth weight and weaning weight. 6 months weight (SW), average daily weight gain from weaning to six month, yearling weight estimated breeding value, weaning weight estimated maternal breeding value and 6 months weight estimated maternal breeding value were highest in the BC genotype. AA genotype was associated with highest average daily weight gain from six to nine month (AGSN). Birth weight estimated breeding value was most in the AB genotype. A selection at lower ages can be performed in Moghani sheep for leptin gene, because high genotypic and phenotypic correlations were observed between weaning weight and body weight at higher ages.