title: Scrapie incidence and PRNP polymorphisms: rare small ruminant breeds of Sicily with TSE protecting genetic reservoirs.
abstract: BACKGROUND
  Transmissible spongiform encephalopathies (TSE) are fatal neurodegenerative diseases of several mammalian species, including humans. In Italy, the active surveillance through rapid tests on brain stem from small ruminants started in 2002 on randomly selected samples of healthy slaughtered animals. Sampling number was proportionally related to the regional small ruminant population. Of the twenty Italian regions, Sicily has the second largest population of small ruminants which is mainly constituted by crossbreed animals (>70 %). Sicily contains also three native sheep breeds Pinzirita, Comisana and Valle del Belice. Native goat breeds are Girgentana, Messinese, Argentata dell'Etna, Maltese and Rossa Mediterranea. The polymorphisms of prion protein gene (PRNP) may influence disease susceptibility and breeding programs for genetic TSE resistance are being applied in sheep. Protective alleles have been recently reported for goats also. These differ from those in sheep and may allow breeding programs in the near future. In this paper the data of active surveillance for scrapie control in general population of small ruminants in Sicily are reported together with the analysis on the polymorphism of PRNP in a number of Sicilian autochthonous breeds. The evaluation of the frequency of protective alleles is fundamental for the implementation of a TSE resistance breeding program.
  
  
  RESULTS
  TSE surveillance in small ruminants in Sicily showed a of total fifty seven scrapie outbreaks from 1997 to 2014 involving mainly crossbreed animals. The PRNP polymorphism analysis in autochthonous breeds showed protective allele frequencies of 30-40 % ARR in sheep and 12-18 % K222 in three of the four goat breeds; these breeds are distributed over limited areas of the island.
  
  
  CONCLUSIONS
  The study on PRNP polymorphisms in Sicilian small ruminant population showed higher frequency of the protective alleles compared to most other European breeds. Our results suggest that PRNP genetic variety in Sicilian sheep and goats can be a resource for TSE resistance breeding programmes while maintaining the conservation of endangered breeds and valorisation of their typical food products.
authors.affiliation: Istituto Zooprofilattico Sperimentale of Sicily "A. Mirri", Palermo, Italy. marvitus@yahoo.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Vitale
authors.affiliation: Istituto Zooprofilattico Sperimentale of Sicily "A. Mirri", Palermo, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Migliore
authors.affiliation: Istituto Zooprofilattico Sperimentale of Sicily "A. Mirri", Palermo, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: La Giglia
authors.affiliation: Istituto Zooprofilattico Sperimentale of Sicily "A. Mirri", Palermo, Italy.
authors.forename: Placido
authors.initials: P
authors.lastname: Alberti
authors.affiliation: Istituto Zooprofilattico Sperimentale of Sicily "A. Mirri", Palermo, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Marco Lo Presti
authors.affiliation: Department of Infection Biology, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
authors.forename: Jan P M
authors.initials: JP
authors.lastname: Langeveld
mesh_terms: D000483:Alleles; D000818:Animals; D015511:Goat Diseases / Q000453:epidemiology / Q000235:genetics*; D006041:Goats; D015994:Incidence; D011110:Polymorphism, Genetic; D000072002:Prion Proteins / Q000235:genetics*; D012608:Scrapie / Q000453:epidemiology* / Q000235:genetics*; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000235:genetics*; D012802:Sicily / Q000453:epidemiology
chemical_list: D000072002:Prion Proteins
keywords: Autochthonous breeds; Breeding programs; PRNP polymorphism; Scrapie surveillance; TSE