Polymorphisms of ovine prion protein (PrP) gene in Pramenka sheepbreed population in Bosnia and Herzegovina

Transmissible spongiform encephalopathies (TSEs) are a group of diseases that affect the nervous system and lead to death. The putative infectious agent is the host-encoded prion protein (PrP) and it appears that the development of scrapie in sheep is closely related to polymorphisms in the host PrP gene. The aim of this study was to investigate three well-known polymorphisms in exon 3 of the PrP gene (at codons 136, 154, and 171) that have a clear and significant effect on scrapie in sheep. Four other polymorphisms (at codons 145, 185, 231, and 237) that are yet undefined were also investigated. The study was performed on the Bosnian Pramenka breed of sheep. Genomic DNA was isolated from venous blood and then a 628 bp long DNA fragment from exon 3 was amplified using the PCR method. The results from this study indicate the presence of seven different genotypes associated with susceptibility to scrapie in the investigated Bosnian sheep population, of which four haplotypes were proven to be susceptible to developing the disease. Two of them were at codon 231 and 237 and have not been described before.