Genetic variability of the prion protein gene in Indonesian goat breeds

Scrapie is a naturally occurring transmissible spongiform encephalopathy in sheep and goats. Resistance or susceptibility of small ruminants to classical scrapie is influenced by polymorphisms in the prion protein gene (PRNP). PRNP variability in Indonesian indigenous goat breeds has not been investigated so far and therefore was the goal of this study. Sanger sequencing of the PRNP gene coding region in 72 goats of the seven Indonesian breeds Kacang, Gembrong, Samosir, Kejobong, Benggala, Jawarandu, and Peranakan Etawah revealed three amino acid substitutions, namely W102G, H143R, and S240P. Some silent mutations were also found at codons 42 (a/g), 138 (c/t), and 179 (g/t). The PRNP alleles K222 and D/S146 known to have significant protective effects on resistance to classical scrapie in goats were not detected. The allele R143, which may have a moderate protective effect, had a frequency of 12% among the analyzed Indonesian goat breeds. While R143 was missing in Kacang and Benggala, its frequency was highest in the breed Gembrong (32%). No scrapie cases have been reported in Indonesia until now. However, in the case that selection for protective PRNP variants would become a breeding goal, the analyzed breeds will not be very useful resources. Other goat breeds which are present in the country should be investigated regarding resistance to scrapie, too.