| Two different scrapie prion strains with different characteristics were
obtained from two sheep naturally infected with scrapie in Japan. In mice
transmission, one (Tsukuba-1) showed shorter incubation periods (133±2
days) than the other (Tsukuba-2) (288±5 days). Spongiform changes
and accumulation of an abnormal isoform of prion protein (PrPSc) were observed throughout the brain in Tsukuba-1 inoculated mice, while
the lesions and the PrPSc accumulation were localized in the brain stem of mice with Tsukuba-2.
A super-infection experiment revealed that neither strain interfered with
the other's propagation. (Prion Research Team, Prion Disease Research Center
TEL +81-29-838-7757) |