Detection of haplotype in the Bovine Prion Protein gene (PRNP) in Najdi, Sarabi and Iranian Holstein cattle breeds

ABSTRACT: Transmissible spongiform encephalopathies are neurodegenerative diseases that affect several mammalian species. Bovine spongiform encephalopathy (BSE) is among the mentioned diseases in cattle caused by abnormally fold prion proteins. Polymorphisms of the prion protein gene (PRNP) have been shown to be major determinations for the susceptibility to transmitted perion diseases in human, mice and sheep. Two regulatory region polymorphisms in the bovine prion gene are associated with resistance and susceptibility to classical BSE disease. Polymorphism (PRNP) as 23-bp and 12-bp insertion and deletion in promoter and intron 1, in both loci are related to resistance but deletion alleles affect inversely. We studied allele, genotype and haplotype frequencies of these two loci among samples of two Iranian cattle breeds including Najdi, Sarabi and Iranian Holstein. Whole blood samples were collected randomly. Selected cows DNA were extracted by Diatom kit. The loci were amplified using primers according to Sander et al. (2004). Genotypes were determined throws running the PCR products of polyacrylamide gel. The allele, genotype and haplotype frequencies were determined by direct counting from gels and analyzed by Fisher Exact test and Chi-square test, respectively. The frequency of 23-bp insertion allele in native cattle was significantly lower than Holstein population (P 0.05) and for 12bp insertion allele native breeds were higher than Holstein significantly (P 0.001). Sarabi population had the highest frequency of 12-bp insertion alleles (0.95). Genotype frequency had also the same trend. In conclusion, Sarabi cattle population have lower genetic susceptibility to BSE than Iranian Holstein population.