Polymorphism of Prolactin and Growth Hormone genes in the Najdi Cattle Breed Using PCR-RFLP

The objective of this study was to determine the polymorphisms of prolactin (PRL) and growth hormone (GH) genes in the Najdi cattle breed. Blood samples were collected from 84 Najdi cows from Khuzestan agricultural research centers in Ahvaz, Shushtar, Hendijan and Mahshahr. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique were used for identification of various genotypes. The results showed that allele frequencies of A and B of PRL gene were 0.571 and 0.429 and frequencies of AA, AB and BB genotypes were 0.2857, 0.5714 and 0.1429, respectively. Moreover, the frequencies of alleles L and V of GH gene were 0.8333 and 0.1667 and the frequencies of LL, LV and VV genotypes were 0.6905, 0.2857 and 0.2380, respectively. The allelic frequencies were intermediate and statistically similar as revealed by x super( 2) test. The results showed that these two populations were in Hardy-Weinberg equilibrium and it is possible that didn't carry out any selection for these loci in the populations.