Fig. 8.

The presence of serine at PrP position 170 is associated with poor amplification of deer, but not vole, PrP^RES. (A) CWD-positive deer brain D10 (Deer brain homog.) and pooled brain homogenate from vPMCA-voles were diluted 1:100 into red-backed vole (Myodes gapperi) NBH. Two replicate samples were subjected to three rounds of PMCA (PMCA+), followed by PK digestion (PK+). The final dilution of each sample was 1:400, represented by a nonamplified (PMCA−) 1:400 dilution for reference (lane 2). Unseeded NBH subjected to three rounds of PMCA followed by PK digestion (NBH) was used in lanes 11 and 12. Samples not digested with PK (PK −, lane 1) demonstrate PrP^C present in the NBH. Results are representative of three experiments. (B) Average densitometric scores (arbitrary units) from panel A were plotted on a graph. Results from experiments using vPMCA-vole brain as seed are represented by triangles and a solid linear regression line, and experiments using deer brain as seed are represented by circles and a dashed linear regression line.