RT Journal Article SR Electronic(1) A1 Goldmann, Wilfred A1 Hunter, Nora A1 Smith, Grace A1 Foster, James A1 Hope, JamesYR 1994 T1 PrP Genotype and Agent Effects in Scrapie: Change In Allelic Interaction With Different Isolates of Agent in Sheep, a Natural Host of Scrapie JF Journal of General Virology, VO 75 IS 5 SP 989 OP 995 DO https://doi.org/10.1099/0022-1317-75-5-989 PB Microbiology Society, SN 1465-2099, AB Man and sheep are the two species in which spongiform encephalopathies occur naturally, and in which there are recognized genetic components that predispose an individual person or sheep to clinical disease. In both species mutations/polymorphisms in the PrP gene have been linked to the incidence of natural disease, but only in sheep is it possible to investigate by deliberate exposure to infection whether these polymorphisms are directly correlated with survival time. Cheviot sheep of different PrP genotypes were challenged with one of two isolates of scrapie or an isolate of bovine spongiform encephalopathy and the survival time and incidence of disease were monitored. Genotype analysis showed that dimorphisms in codons 136 and 171 of the ovine PrP gene correlated with control of disease incidence and modulation of incubation time. Crucially, the functional effects of these domains of PrP were shown to alternate depending on the isolate of infecting agent., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-75-5-989