title: Prion protein polymorphisms and estimation of risk of scrapie in East Asian sheep.
abstract: Allele and genotype frequency distributions of prion protein (PrP) polymorphisms at three codons, 136, 154, and 171, in East Asian sheep were determined by PCR-RFLP analysis using 553 animals from nine local breeds of the northern group and four local breeds of the southern group. Based on the genotype distribution, the risk score for scrapie was estimated. Among the local breeds, ARQ appeared predominantly (0.7701-1), followed by ARH and ARR. From such a biased allele distribution, it was difficult to ascertain the prevalent genetic relationships. A marked difference in allele frequencies between the northern and southern groups was seen (P < 0.0001). The East Asian sheep had ARQ at the highest frequency (0.8834); in European sheep it was 0.5317. According to an assessment of scrapie risk in the PrP genotype classes, the predominant ARQ/ARQ in East Asian sheep corresponded to the risk score of R4. This finding suggests that East Asian sheep have a high level of genetic susceptibility to scrapie.
authors.affiliation: Department of Legal Medicine, Showa University School of Medicine, Tokyo, Japan. tsunoken@med.showa-u.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsunoda
authors.forename: Takao
authors.initials: T
authors.lastname: Namikawa
authors.forename: Keizo
authors.initials: K
authors.lastname: Sato
authors.forename: M A
authors.initials: MA
authors.lastname: Hasnath
authors.forename: Maung Maung
authors.initials: MM
authors.lastname: Nyunt
authors.forename: Heramba B
authors.initials: HB
authors.lastname: Rajbandary
authors.forename: Chau Ba
authors.initials: CB
authors.lastname: Loc
authors.forename: Ts
authors.initials: Ts
authors.lastname: Zanchiv
authors.forename: Hong
authors.initials: H
authors.lastname: Chang
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Tasi
authors.initials: T
authors.lastname: Dorji
mesh_terms: D000818:Animals; D003062:Codon / Q000235:genetics; D017931:DNA Primers; D005060:Europe / Q000453:epidemiology; D005202:Asia, Eastern / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011328:Prions / Q000235:genetics*; D012608:Scrapie / Q000453:epidemiology* / Q000235:genetics; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology* / Q000235:genetics
chemical_list: D003062:Codon; D017931:DNA Primers; D011328:Prions