GENETIC STRUCTURE OF TURCANA BREED, SIBIAN ECOTYPE AT OVINE PRN-P LOCUS

R. Constantinescu, Viorica Coşier, A. Vlaic, Vioara Mireşan, Camelia Raducu, D. Cocan, Iulia Feştilă

Abstract
Scrapie in sheep and goats, is the longest known and most widely spread of transmissible encephalopathies (T.S.E s) or prion diseases, that also include Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy (B.S.E) in cattle. The Ppn-p locus is polymorphic with known variability at codon 136, 154, 171 in sheeps, which are associated with different sensibility in experimental and natural spongiform encephalopaties. General the possible combinations of the 5 amino acids encoded by the 3 different codons will determine the existence of 15 possible genotypes. To put in evidence those polymorphisms at the ovine Prn-p locus, several methods are developed but the most accurate assay is the direct sequencing of the gene and the primer extension technique. The purpose of this study was to determine the genetic structure at Prp locus in 322 male of Turcana breed, Sibian ecotype, using primer extension technique (ABI 3130xl Genetic Analyzer), and to establish the risk groups of the susceptibility at scrapie disease.

Key words: scrapie, codon, Prnp locus, primer extension, genetic structure