Analysis of the ORF region of the prion protein gene in the Botosani Karakul sheep breed from Romania

Ovine scrapie is considered a neurodegenerative disease characterized by the accumulation of an abnormal, protease-resistant isoform of PrP. The polymorphisms at codons 136, 154, and 171 are associated with susceptibility to scrapie. In order to detect the existing polymorphisms at the 3 codons we used the real-time PCR technique. The obtained genotypes were confirmed by PCR amplification and sequencing of a 402 bp fragment of exon 3 of the prion gene. Known polymorphisms were detected at codons 136, 154, and 171 and 5 different genotypes were determined. The results showed that all animals were homozygous for A at codon 136 and homozygous for R at codon 154 and 3 out of 4 previously identified polymorphisms at residue 171 were detected (R, H, and Q). Two new polymorphisms were detected at codon 189 and 199, as well as 2 other reported polymorphisms at codons 141 and 143. The frequency of high risk ARQ/ARQ genotype was about 47%. The aim of this study was to determine same preliminary information on the PrP gene-associated susceptibility in scrapie in the Botosani Karakul sheep breed.