Phenotype of WT and Cald1^−/− E18.5 animals. (A) In contrast to WT (Cald1^+/+), Cald1^−/− littermates (KO) displayed an umbilical hernia; white bars, 5 mm. (B) Enlarged view of the umbilical hernia. (C) Nissl stain of sections of E18.5 fetuses. (D) Enlarged view showing that the umbilical hernia is covered with membranes (arrows) characteristic of an omphalocele. (E) Impaired fusion of the lower sternum (xiphoid, arrows) in KO as opposed to WT. (F) Relation between body weight and gestational age; symbols represent mean ± SD; n = 3–70 fetuses; solid lines: monoexponential fit (rate constants; k_WT = 0.345 d, k_KO = 0.321 d, k is not different between datasets). (G) Relation between litter size and gestational age. The litter size was not different between E13.5 and E18.5 litters but was lower in E19.5 litters; symbols represent mean ± SD; the number of litters at each gestational age is given in Table 2. *, P < 0.05; **, P < 0.01 (one-way ANOVA followed by Sidak’s multiple comparison test).