SURVEY OF CAPRINE PRNP ALLELE FREQUENCIES OF TWO SPANISH NATIVE BREEDS OF GOATS AND THEIR RELEVANCE FOR GENETICALLY DETERMINED TSES RESISTANCE

The development of a TSE in an animal depends largely on variation of the PRNP gene of the host, which is responsible for encoding the cellular protein PrPc. Different polymorphisms may influence the conversion of PrPc in PrPsc, causing an increase of prion disease susceptibility or a change in the length of the incubation period of the disease (Bossers, 1997). Several studies of natural and experimental scrapie infection in goats show how allelic variations in the PRNP gene can modulate the disease susceptibility and resistance (Goldmann, 1996). Twelve silent mutations and 34 amino acid substitutions have so far been described (Vaccari, 2009; Bouzalas, 2010; Acin, 2013), of which at least 8 appear to be related to disease susceptibility: G127S, I142M / I142T, S146N, R154H, R211Q / R211G and Q222K. It is therefore interesting to study the PRNP gene in the population of Spanish native breeds of goats, in order to define their risk status, select animals with high genetic merit and to encourage farmers to maintain and reproduce those specimens. In this study, more than 1300 animals out of a total of 3000 goats of two native breeds (Moncaina and Murciano-Granadina) have so far been genotyped,. 16 females from the Moncaina breed have been found as carriers of the 222K polymorphism, 15 heterozygotes) and one homozygote (). Those animals are now under surveillance and a deep investigation has been started in order to detect the 222K carrier male of the herd. Furthermore a single animal was found carrying the polymorphism Q171R, a mutation that is known to confer resistance against scrapie in sheep, and that have been described previously in one goat from a Greek herd (Bouzalas et al., 2010). Breeders and farmers are aware and agree to breed them for resistance to scrapie and BSE.