Table 1 . DS-associated phenotypes found in Ts65Dn and Ts1Rhr mice on different genetic backgrounds.

Strain	Background	Trisomy	Body size	Brain	Cerebellum	Hippocampus	LTP	Functional tests	E9.5 PA1		Ets2	Dyrk1a	Rcan1
Ts65Dn	B6C3Fn	∼104 genes	Smaller, shorter femura	Similarb	Reducedb	Reducedc	Decreasedd	Abnormal Morris watere	Reduced, fewer NCsf		3	3	3
Ts1Rhr	50% B6, 25% 129, 25% C3H	∼33 genes	Larger,a,g longer femura	Smallerg	Reducedg				Not significant but slightly largerh,i		3	3	2
	50% B6, 50% 129		Largerj	Largerj	Reducedh,j	Similarh,j
	100% B6						Normal (CA1)j	Normal Morris waterj	Enlarged, more NCsi
	B6C3Fn		Largerk	Largerk		Similark	Decreased (fascia dentata)k	Impaired object recognition,k inferior T maze, thigmotaxick

^aOlson et al. (2004).

^bBaxter et al. (2000).

^cLorenzi and Reeves (2006).

^dSiarey et al. (1997).

^eEscoriheula et al. (1995).

^fRoper et al. (2009).

^gAldridge et al. (2007).

^hNormalized for size.

ⁱThis study.

^jOlson et al. (2007).

^kBelichenko et al. (2009).