Identification of the presence of a scrapie resistance gene in sheep on the territory of the Republic of Serbia

Abstract

Monitoring of scrapie in sheep and goats has been carried out for many years in Serbia. Despite many years of monitoring, only one case of this disease has been reported in sheep, but given that, there are numerous cases of the disease in some neighboring countries, it is very important to determine the presence of resistant genes in the sheep population in Serbia. Genetic susceptibility to scrapie is influenced mainly by the prion protein polymorphisms of codons136, 154, and 171. The ARR allele is considered to provide very strong resistance against classical scrapie and the VRQ genotype is the most susceptible. In order to examine the genetic makeup of sheep in Serbia related to scrapie, we optimized TaqMan probes of real-time polymerase chain reaction (qPCR) techniques for three codons. We analyzed blood samples from 100 sheep using qPCR and the results showed that AA homozygous for the 136 codon were the most common. For codon 154 the most frequent genotype was RR and for codon 171 the most frequent genotype was QQ.