Abstract

ARTIGAS, R. et al. Polymorphisms of the 136 and 171 codons in the PrP gene in Uruguayan Creole sheep. Arch. zootec. [online]. 2011, vol.60, n.231, pp.817-820. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922011000300070.

scrapie is a transmissible neurodegenerative disorder of sheeps and goats. It is characterized by the deposition in the central nervous system of an abnormal isoform of a normal cellular protein (PrPc), coded by the PrP gene. Mutations at 136, 154 and 171 codons of exon 2, are described. Combinations of these codons show different levels of association with the susceptibility to this disease; from highly resistants (ARR/ARR) to highly susceptibles (VRQ/VRQ). Codons 171 and 136 are the main determinant of scrapie susceptibility while codon 154 plays a minor role. In the present communication, a sample of Uruguayan Creole sheeps (N=28) was analysed for 136 and 171 codons. Samples of genomic DNA were processed by PCR-RFLP. The results were obtained by electrophoresis in polyacrylamide gel (10.5%) stained with AgNO₃. Genotypic frequencies for the 136 and 171 codons were analysed. The results revealed 5 different genotypes. The most frequent genotypes were those associated with more susceptibility to the disease: VQ/AQ= 0.39 y AQ/AQ= 0.29. The analysis of genetic risk revealed a 72% of highly susceptible individuals, in case of proper environmental conditions.

Keywords : Creole sheep; PCR-RFLP; scrapie.

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