Genotyping of PrP gene in native Turkish sheep breeds

Abstract

Scrapie is an infectious fatal disease of sheep that affects the central nervous system. Polymorphisms in sheep PrP gene are known to be related to scrapie susceptibility. Selection programmes for scrapie based on PrP genotyping data are available for many of the European sheep breeds. So far comparable data for local Turkish sheep breeds are not available. The aim of this study was genotyping of PrP gene in Turkish native sheep to find out their risk groups. Therefore, in this study 109 native Turkish sheep belonging to Kivircik, Sakiz and Imroz breeds were genotyped by means of PCR and direct sequencing. The polymorphism detected in the prion gene was made up six alleles ARR, ARQ, AHQ, VRQ, TRQ, ARH and 12 genotypes, ARR/ARR, ARR/TRQ, ARR/ARQ, ARQ/AHQ, ARH/TRQ, TRQ/TRQ, ARQ/TRQ, ARQ/ARQ, ARQ/ARH, ARH/ARH, ARR/VRQ and ARQ/VRQ. In addition, eight polymorphisms were identified (M112T, A116E, R138M, N146S, Y172D, S173N, V179E and R231R) at different codons of PrP gene. The data have shown that PrP genes of the analysed sheep are highly variable and the most of the genotypes belong to risk groups 1 and 2. (c) 2007 Elsevier B.V. All rights reserved.