Table 1.

Litter size and litters per month (mean ± sem) in wild-type (WT) and transgenic (TG) mice bred from 1.5 to 5 or to 11 months of age

Genotype	Breeding period	Pups per litter
WT	1.5–5 months old	8.09 ± 0.378
WT	6–11 months old	7.96 ± 0.224
TG	1.5–5 months old	7.95 ± 0.221
TG	6–11 months old	8.35 ± 0.254

Genotype	Breeding period	Litters per month
WT	1.5–5 months old	0.88 ± 0.06
WT	6–11 months old	0.82 ± 0.05
TG	1.5–5 months old	0.98 ± 0.03a
TG	6–11 months old	0.77 ± 0.05a

^aStatistically significantly different.