Evaluation of Resistance and Susceptibility to Prion Diseases in Pelibuey Sheep from Mexico

Abstract Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases with chronic and fatal course, which caused by misfolded form the cellular prion protein that is encoded host. The purpose this work was to evaluate resistance genetic susceptibility in Pelibuey sheep from Mexico. sequences 99 central southwestern regions Mexico were analyzed determine polymorphisms related scrapie, Hardy-Weinberg equilibrium test D-Tajima used identify effect evolutionary forces on PRNP gene. Twelve non-synonymous Q101R, M112T, A116P, G127A, A136V, M137T, L141F, H143R, R154H, Q171R, Q171H, N176K detected, addition two synonymous substitutions 231R (agg/cgg) 237L (ctc/ctg) found. As result sequence analysis, ARR allele not under equilibrium, indicating there an force at work, suggest existence purifying selection. In conclusion, exhibit genotypes for gene make them resistant developing classic scrapie; least 98% population carrier scrapie resistance; while atypical very high probability outbreak occurred herds, since ARQ combination L substitution codon 141 confers sheep.