Deletion of one Akt2 allele in Akt1 -deficient mice exacerbates their lactation defect. (a) Postpartum weight gain in pups nursed by Akt foster mice. Average daily pup weights for litters nursed by Akt1+/+;Akt2+/+ mice, Akt1-/-;Akt2+/+ mice, Akt1+/+;Akt2-/- mice, Akt1-/-;Akt2+/- mice, or Akt1+/-;Akt2-/- mice. Statistical analysis was calculated by mixed model with first-order autoregressive covariance structure. (b) Pup survival in litters nursed by Akt foster mice. Pup survival was defined as the percentage of mice that survived to postpartum day 9. (c) Milk yield collected from the thoracic and abdominal mammary glands of mice with indicated Akt genotypes at day 9 of lactation after oxytocin stimulation.