title: Frequencies of PrP genotypes in meat breeds of Japanese sheep and trail of selective breeding in experimental sheep flock.
abstract: The selection of sheep with scrapie-resistant PrP genotypes is one of the control measures for transmissible spongiform encephalopathies in ruminants. In this study, we investigated the frequencies of PrP genotypes in meat breeds in Japan. The nationwide surveillance revealed that nearly half of the Suffolk sheep, a major meat breed in Japan, carried scrapie-susceptible AQ/AQ and AQ/VQ genotypes. In addition, the VQ haplotype, which confers high susceptibility to scrapie within sheep, was also found in Poll Dorset sheep. A trial of selective breeding using sires with scrapie-resistant PrP genotypes AQ/AR and AR/AR could raise the ratio of scrapie-resistant sheep from less than 50% to 80% within 3 years. However, the use of sires with the AR/AR genotype and the selection of ewes would be required to achieve a higher ratio of scrapie-resistant sheep.
authors.affiliation: Laboratory of Prion Diseases, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Ohara
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Togari
authors.forename: Aya
authors.initials: A
authors.lastname: Kurokawa
authors.forename: Junko
authors.initials: J
authors.lastname: Maeda
authors.forename: Naotaka
authors.initials: N
authors.lastname: Ishiguro
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Furuoka
authors.forename: Motohiro
authors.initials: M
authors.lastname: Horiuchi
mesh_terms: D000818:Animals; D001947:Breeding; D005260:Female; D005838:Genotype; D007564:Japan; D008297:Male; D011328:Prions / Q000235:genetics*; D012608:Scrapie / Q000235:genetics*; D012756:Sheep / Q000235:genetics*
chemical_list: D011328:Prions