The first transmissions of human prion diseases to rodents used guinea pigs (Gps, Cavia
porcellus). Later, transgenic mice expressing human or chimeric human/mouse PrP
replaced Gps, but the small size of the mouse limits some investigations. To investigate the
fidelity of strain-specific prion transmission to Gps, we inoculated 'type 1'and 'type 2'prion
strains into Gps, and we measured the incubation times and determined the strain-specified
size of the unglycosylated, protease-resistant (r) PrP Sc fragment. Prions passaged once in …