Fig. 5.

Cdkn1c mutant embryos are able to reach their intrinsic growth potential when intrauterine competition is low. Embryonic weights for pups in litters with three to five pups versus litters of six or more pups. Mutant pups from litters with three to five pups were 119% the weight of wild type (1314±166 mg versus 1102±151 mg; six litters; P=0.002 by Student’s t-test), whereas the mutants from litters of six or more pups were 107% the weight of wild type (1095±105 mg versus 1156±158 mg; 15 litters; P=0.016). The weights of mutants in smaller litters were significantly different to the weights of mutants in larger litters (P<0.05 by ANOVA, Tukey-Kramer post hoc test), whereas wild-type weights did not differ between litter sizes (P>0.05).