TABLE 1.

Susceptibility of transgenic and nontransgenic mice to intracerebral inoculation with two isolates of sheep scrapie^a

Line	Genotypeb	PrP-encoding gene		tg copy number	PrPc level (fold)c		Days to terminal disease (n/n0) following inoculation withd:
		Sheep	Mouse		Sheep	Mouse	PG127	LA404
RIII	Prnp+/+		Prnpa			1	423 ± 6.1 (8/8)	>600 (2/5)
F1e	Prnp+/+		Prnpa			1	566 ± 8 (8/8)	620 ± 22 (7/8)
tg301	tg3+/−, Prnp0/0	bacPrnpVRQ		6	8		73 ± 3 (7/7)∗	205 ± 12.8 (10/10)∗
tg328	tg3+/−, Prnp0/0	bacPrnpVRQ		4	3.5		101 ± 5 (8/8)∗	na
tg206	tg2+/−, Prnp0/0	cmv/phgPrnpVRQ		9	2.2		113 ± 4.4 (7/7)∗	na
tg211	tg2+/−, Prnp0/0	cmv/phgPrnpVRQ		4	1.9		107 ± 2.7 (12/12)∗	341 ± 5 (8/8)∗
tg223	tg2+/−, Prnp0/0	cmv/phgPrnpVRQ		19	1.6		143 ± 5 (8/8)∗	na
tg143	tg1+/−, Prnp0/0	phgPrnpVRQ		30	1.5		149 ± 4.3 (8/8)∗	351 ± 5 (8/8)∗
tg207	tg2+/−, Prnp0/0	cmv/phgPrnpVRQ		8	1.2		196 ± 10 (8/8)∗	na
tg335	tg3+/−, Prnp0/0	bacPrnpVRQ		1	1.2		200 ± 9.3 (6/6)∗∗	na
tg116	tg1+/−, Prnp0/0	phgPrnpVRQ		4	>0.4		399 ± 6 (7/7)	na
tga20f	tga20+/+, Prnp0/0		phgPrnpa	60f		10f	240 ± 3 (8/8)	413 ± 16.8 (6/6)

^aHeated 10% brain homogenate. 

^btg1, tg2, and tg3 as described in the legend to Fig. 1; Prnp^0/0 as described in reference 7. 

^cCompared to level of sheep or wild-type (C57BL/6) mouse brain. 

^dValues are means ± standard errors of the means. Each value in parentheses is the number of animals terminally ill/the number of animals inoculated. Statistical comparison to tga20 was performed with the unpaired Student's t test. ∗, P < 0.005; ∗∗, P ≤ 0.05. na, not available. 

^eF₁, (C57BL/6 × 129/Sv)F₁. 

^fAs described in reference 18.