Transmission of atypical scrapie to homozygous ARQ sheep.
Two Cheviot ewes homozygous for the A136L141R154Q171(AL141RQ) prion protein (PrP) genotype were exposed intracerebrally to brain pools prepared using four field cases of atypical scrapie from the United Kingdom. Animals were clinically normal until the end of the experiment, when they were culled 7 years post-inoculation. Limited accumulation of disease-associated PrP (PrPSc) was observed in the cerebellar molecular layer by immunohistochemistry, but not by western blot or enzyme-linked immunosorbent assay. In addition, PrPScwas partially localized in astrocytes and microglia, suggesting that these cells have a role in PrPScprocessing, degradation or both. Our results indicate that atypical scrapie is transmissible to AL141RQ sheep, but these animals act as clinically silent carriers with long incubation times.
National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki 305-0856, Japan.
Hiroyuki
H
Okada
Kohtaro
K
Miyazawa
Morikazu
M
Imamura
Yoshifumi
Y
Iwamaru
Kentaro
K
Masujin
Yuichi
Y
Matsuura
Takashi
T
Yokoyama
D000818:Animals; D001921:Brain / Q000473:pathology; D005260:Female; D006720:Homozygote; D007150:Immunohistochemistry / Q000662:veterinary; D055256:Infectious Disease Incubation Period; D000072002:Prion Proteins / Q000235:genetics*; D012608:Scrapie / Q000235:genetics / Q000473:pathology / Q000635:transmission*; D012756:Sheep / Q000235:genetics
D000072002:Prion Proteins