Association of ghrelin gene polymorphism with growth related traits in Mazandaran native fowls

Ghrelin or releasing growth hormone gene is a peptide hormone consists of 26 amino acids in fowl. This peptide causes a positive energy balance by stimulation growth hormone secretion, food intake, body weight gain and also causes obesity. In this study three specific primer sets of RP-LI, RP-L3 and RP-L5 were used in order to detect polymorphism in nucleotide at positions 71, 1215 and 2355 of ghrelin gene respectively, using RFLP-PCR. Three DNA fragments with 369, 320 and 228 bp were amplified and the PCR products for each primers of RP-L1, RP-L3 and RP-L5 were digested with MboII, Eco72I and HeaIII endonuclease, respectively. Four types of genotypes TC, CC, TB and CB were found for nucleotide site of 71 with the frequency of 5, 37, 47 and 11%, respectively. No any allelic forms were found in nucleotide site of 1215 and all genotyped birds showed monomorph (AA) genotype. At nucleotide site of 2355 of ghrelin gene two genotypes AB and BB were found with the frequency of 25 and 75%, respectively. Statistical analysis showed significant association (p<0.05) between nucleotide site of 2355 with hatch weight (HW).