title: Prion protein gene polymorphisms in healthy and scrapie-affected sheep in Greece.
abstract: A total of 216 local crossbred sheep from 16 scrapie-affected Greek flocks and 210 purebred sheep of the milk breeds Chios and Karagouniko from healthy flocks were analysed for scrapie-linked polymorphisms in the prion protein (PrP) gene. Of the 216 sheep in this case-control study, 96 sheep were clinical cases, 25 subclinical cases (asymptomatic at the moment of euthanasia but positive by histopathology and/or ELISA detecting proteinase-resistant PrP) and 95 healthy controls (negative by all evaluations). Polymorphisms at codons 136, 154 and 171 were determined by denaturing gradient gel electrophoresis, followed by RFLP and sequencing. Scrapie, both clinical and subclinical, was associated with the genotypes ARQ/ARQ (88 of 110 sheep of that genotype), ARQ/TRQ (9 of 13), ARQ/AHQ (15 of 38) and VRQ/VRQ (9 of 17). Histopathological lesions were more severe in the clinical cases. Genotypes ARQ/ARR (26 sheep), ARQ/ARK (seven sheep), AHQ/ARR (one sheep), ARH/ARH (one sheep) and ARR/ARH (three sheep) were detected exclusively in healthy control sheep. In the purebred survey, four genotypes were present in the Chios sheep (ARQ/ARQ, ARQ/TRQ, ARQ/AHQ and ARQ/ARR) and four in the Karagouniko sheep (ARQ/ARQ, ARQ/AHQ, ARQ/ARR and ARQ/ARH).
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Billinis
authors.affiliation: Laboratory of Pathology, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Vassilios
authors.initials: V
authors.lastname: Psychas
authors.affiliation: Laboratory of Epidemiology, Biostatistics and Economics of Animal Production, Faculty of Veterinary Medicine, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece.
authors.forename: Leonidas
authors.initials: L
authors.lastname: Leontides
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Spyrou
authors.affiliation: Clinic of Productive Animal Medicine, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Stamatis
authors.initials: S
authors.lastname: Argyroudis
authors.affiliation: Laboratory of Pathology, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vlemmas
authors.affiliation: Laboratory of Pathology, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Sotirios
authors.initials: S
authors.lastname: Leontides
authors.affiliation: Laboratory of Pharmacology, Department of Pharmaceutical Sciences, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Sklaviadis
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Aristotle University, GR-54124 Thessaloniki, Greece.
authors.forename: Orestis
authors.initials: O
authors.lastname: Papadopoulos
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D003062:Codon; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006115:Greece / Q000453:epidemiology; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011328:Prions / Q000235:genetics* / Q000472:pathogenicity; D012608:Scrapie / Q000453:epidemiology / Q000235:genetics*; D012756:Sheep / Q000235:genetics*
chemical_list: D003062:Codon; D011328:Prions