Table 1.

Perinatal lethality, fertility, and lactation defect in SirT1^ko/ko mice

Parents		Pups
Male	Female	Litter	Survivorsa	+/+	+/ko	ko/ko
+/ko	+/ko	47	340	101	208	31
ko/ko (n = 3)	+/ko	11	55	-	45	10
+/ko	ko/ko (n = 5)	8	0	-	(13)	(13)

More than 10 pairs of SirT1^+/ko male mice and SirT1^+/ko female mice were used for breeding. Data in parentheses indicate the number of pups of this genotype found dead within 3 days after their birth. ^aTotal number of surviving pups at weaning (postnatal day 21).