TABLE 4.
Scrapie incubation periods and PrPSc deposition in central nervous system and lymphoid tissues in intracerebrally inoculated goats, shown according to genotypes at codons 142, 154, 211, 222, and 240 of the PRNP genea
| Genotype | No. of clinically TSE-affected animals/total no. of animals | Scrapie incubation period (dpi) (mean ± SD) | Death from intercurrent disease |
PrPSc accumulation (no. of goats/total no. examined) |
||
|---|---|---|---|---|---|---|
| No. of goats/total no. in group | Time to death (dpi) | CNS | Lymphoid tissuesb | |||
| I142R154R211Q222/IRRQ (wild type) | 5/5 | 486 ± 21 | 5/5 | 5/5 | ||
| M142RQ/IRRQ | 5/5 | 788 ± 99 | 5/5 | 5/5 | ||
| IH154RQ/IRRQ | 5/5 | 624 ± 148 | 5/5 | 0/5 | ||
| IRQ211Q/IRRQ | 5/5 | 1,291 ± 325 | 5/5 | 5/5 | ||
| IRQ211Q/IRRQ211Q | 10/10 | 770 ± 139 | 10/10 | 1/10 | ||
| IRRK222/IRRQ | 2/5 | 1,900, 2,174 | 3/5 | 568, 898, 1,062 | 2/5c | 0/5 |
| IRRK222/IRRK222 | 1/5 | 2,101 | 1/1 | 0/1 | ||
a
Groups of five goats were intracerebrally challenged in the temporal cortex with the same classical scrapie isolate used for oral challenge. Animals that were still alive were at >2,400 days postinoculation at the time of writing.
b
Tonsils, prescapular lymph nodes, ileal/jejunal Peyer's patches, and mesenteric lymph nodes.
c
The two PrPSc-positive animals were clinically affected.