(A) Survival of pups born to TDAG51-/- dams. The photographs were obtained on postnatal day 1 (P1). Arrowheads indicate dead pups. Dotted circles indicate pups gathered in a nest. +/+, TDAG51+/+ dams. +/-, TDAG51+/- dams. -/-, TDAG51-/- dams. (B) The average number of pups born to TDAG51-/- dams. The number of pups per dam was analyzed on P0. Black bar (+/+), TDAG51+/+ dams. Gray bar (+/-), TDAG51+/- dams. White bar (-/-), TDAG51-/- dams. (C) The survival rate of pups born to TDAG51-/- dams. Pup survival was measured from P0 to P2 in the absence of male mating partners. (D) The survival rate of pups with surrogate TDAG51-/- dams. A schematic diagram of the cross-fostering experiment between TDAG51+/+ and TDAG51-/- dams is shown in the left panel. Pups born to TDAG51+/+ and TDAG51-/- dams were interchanged on P0, and the survival of the cross-fostered pups with their surrogate dams was analyzed on P2. Black bar (+/+), TDAG51+/+ surrogate dams. White bar (-/-), TDAG51-/- surrogate dams. (E) The effect of male mating partners on the survival of pups born to TDAG51-/- dams. Pup survival was analyzed from P0 to P2 in the presence of the male mating partner. Black bar, TDAG51-/- dams with TDAG51+/+ male mice. White bar, TDAG51-/- dams with TDAG51-/- male mice. **p<0.01. n.s., not significant.