Study of kappa-Casein and Growth Hormone genes polymorphisms by PCR-RFLP method in Mahabadi goat

Caseins and Growth Hormone genes are linked to milk production and it,s major technical features such as coagulation, flocculation characteristics and cheese production, so have been taken into consideration in these gene polymorphism as Candidate genes. The aim of this study was detection of polymorphism at 660 bp region of exon 4 of the kCasein and 422 bp region of exones 2 and 3 of the GH genes in Mahabadi goats breed. Due to this purpose, a total of 100 Iranian Mahabadi goat blood sawples were collected. PCR-RFLP method with HaeIII restriction enzyme with two pairs of primers were used to detect alleles A or E in exon 4 of the k-Casein gene and alleles A and B in exones 2 and 3 of the GH gene. PCR amplified products were observed and the restriction analysis by enzyme HaeIII produced two fragments of 430 bp and 230 bp that exhibiting the presence of allele A with frequency 100% in k-casein gene. Allele E was not observed. For GH gene, two fragments of 366 bp and 56 bp that exhibiting genotype AA and three fragments of 422 bp, 366 bp and 56 bp that exhibiting genotype AB were produced. Calculated frequencies for AA and AB genotypes were 0.14 and 0.86, respectively. Frequencies of alleles A and B were 0.57 and 0.43, respectively. BB genotype was not observed. According to the results, in the tested Mahabadi goat population, monomorphism and polymorphism patterns observed at amplified sequences of the kCasein and GH genes, respectively.