Biodiversity and selection for scrapie resistance in goats: Genetic polymorphism in “Girgentana” breed in Sicily, Italy

Abstract

Breeding for scrapie resistance in sheep, has being implemented in Europe as an efficient eradication policy. In goats, in contrast, the analysis on prion gene (PRNP) polymorphisms showed that some polymorphic variants can be protective for the disease but their prevalence in different breeds is still under investigation. Currently, in the presence of positive goats a complete cull of the herd is performed with a great economic loss and a serious threat of extinction for the endangered breeds.A polymorphism that seems related to caprine scrapie resistance is present at the codon 222 of the PRNP, with a lysine (K) instead of glutamine (Q) but this variant is not present in several widely diffused goat breeds in different countries. To evaluate the prevalence of the K222 variant in local goats we studied the “Girgentana”, an endangered autochthon dairy breed. The dairy products from the milk of this breed, with an excellent balance between fat and proteins are very typical and considered a “Slow Food” presidium.The results showed that K222 variant is common in Girgentana breed (18,7%) suggesting a rapid realization of a breeding plan for scrapie resistance based on K222 allele, in contrast to commercially widely used alpine breeds such as Saanen, that have a lower prevalence of this allele. The results suggest that genetic biodiversity might be a great resource for the selection of scrapie resistance, for the conservation of endangered breeds and their typical food productions.