A cross-sectional study of PRNP gene in two native Sicilian goat populations in Italy: a relation between prion gene polymorphisms and scrapie incidence

Abstract

Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases affecting humans and animals, and scrapie in small ruminants is considered the archetype of TSEs. Derivata di Siria is a native dairy goat of Sicily (south Italy), which is related to Syrian goat breeds. Scrapie disease is considered endemic in Sicily since 1997, following the administration of an infected vaccine.Derivata di Siria goatswere involved in six of 66 scrapie-infected flocks in Sicily. Prion protein gene (PRNP) analysis revealed that none of the scrapie cases carried the p.Gln222Lys variant. Sequencing of PRNP in this goat population showed a high frequency (15%) of p.Gln222Lys variant confirming its association with scrapie resistance. PRNP polymorphisms were also analysed in the population of Pantelleria, a small Sicilian Island, where scrapie has never been reported. The native goat breed 'Pantesca' was maintained up to almost 80 years and the size of the sheep population on this island has historically been very low. Currently, a crossbreed goat population of 253 heads is present on the island. PRNP genotyping of Pantelleria goats showed genetic variation, with low presence of wild-type goats and the lack of protective alleles. These data reinforce the association between PRNP polymorphisms in small ruminants and scrapie incidence.

Analysis of differences in prion protein gene (PRNP) polymorphisms between Algerian and Southern Italy's goats

“…Scrapie incidence is higher in South and Central Italy compared to the northern regions and the highest incidence has been observed in some provinces of Sicily, Sardinia and Central Italy probably related to the usage of a contaminated vaccine as shown in Figure 3 (Bertolini et al 2012). Highfrequencies were detected in Aspromontana (10.3%) and Cilentana (18.2%) similar to the previously described Sicilian goats (Girgentana and Rossa Mediterranea in Table 1) in which a direct relation of its high prevalence with the high-scrapie incidence has been postulated (Migliore et al 2017). In Italy, northern breeds showed low-frequencies of K222 (Acutis et al 2008) but also a lower incidence of scrapie as reported in Bertolini et al (2012).…”

“…However, a recent study showed its strong relation to scrapie resistance in Canadian dairy goats independently from K222 presence (Srithayakumar et al 2016). The South Italian breeds showed six polymorphisms and both confirmed a high-level of the allele resistant K222 as previously observed for the Sicilian goats (Migliore et al 2015;Vitale et al 2016) where a relation with high-scrapie incidence has been postulated (Migliore et al 2017). Scrapie incidence is higher in South and Central Italy compared to the northern regions and the highest incidence has been observed in some provinces of Sicily, Sardinia and Central Italy probably related to the usage of a contaminated vaccine as shown in Figure 3 (Bertolini et al 2012).…”

Five Novel PRNP Gene Polymorphisms and Their Potential Effect on Scrapie Susceptibility in Three Native Ethiopian Sheep Breeds

“…Genetic based eradication program is one of the reasons why ARR haplotype is prevalent in such areas [26,27]. A study by Migliore S. et al,2017, speculated positive selection on scrapie resistance goat PRNP variants in the places where there was scrapie epidemics [28]. Similarly, in India, China, Israel, Iran, and Turkey where scrapie case has never been epidemic, the predominant allele was ARQ [29][30][31][32][33][34][35].…”

Five Novel PRNP Gene Polymorphisms and Their Potential Effect on Scrapie Susceptibility in Three Native Ethiopian Sheep Breeds

“…Genetic based eradication programs are one of the reasons why ARR haplotype is prevalent in such areas [26,27]. A study by Migliore S. et al,2017, speculated positive selection on scrapie resistance goat PRNP variants in the places where there was scrapie epidemics [28]. Similarly, in India, China, Israel, Iran, and Turkey where scrapie case has never been epidemic, the predominant allele was ARQ [29][30][31][32][33][34][35].…”