Genetic Polymorphisms and Association of Growth Hormone Gene with Growth Traits in Beetal Goat

Abstract

Background: This investigation was aimed to determine the association of growth hormone GH1 (A781G) and GH2 (A1575G) locus with growth traits in Beetal goats by using PCR-RFLP method. Methods: A total of 60 blood samples from Beetal goat were collected along with growth records (body weight in kg) at 0, 3, 6, 9 and 12 month of age maintained at Goat Dairy Farm Rajbagh, Jammu. DNA was extracted from blood samples by using DNA extraction kit. The target segment of GH 1 and 2 locus was amplified and digested with HaeIII restriction enzyme for scoring of genotypes. Result: The amplified PCR product obtained for GH1 (422 bp) and GH2 (116 bp) locus were digested with HaeIII restriction enzyme at 37°C for 15 min. The resultant digested products revealed three genotypes for GH1: AA (422 bp), BB (366 bp, 56 bp) and AB (422 bp, 366 bp and 56 bp) whereas, one genotype was observed for GH2 i.e., BB (88bp and 28bp). The genotypic frequencies in Beetal goat for GH1 were found to be 0.05 for AA genotype, 0.80 for AB genotype, 0.15 for BB genotype, whereas gene frequencies was 0.45 for A allele and 0.55 for B allele. GH2 locus was found to be monomorphic. The highly significant (P less than 0.01) Chi-square (χ²)-test value for GH1 locus showed that the population was not in HWE. BB genotype has a significantly higher (P less than 0.01) body weight followed by AA and AB genotypes at 9 and 12 month of age. Thus, GH1 locus can be used as a candidate gene to improve growth traits and selection of superior animals at an early age of 9 months for phenotypic selection programmes in Beetal goats.