Fig. 1. Fertility and growth of wild-type and Vdr knockout mice. Homozygous wild-type and Vdr knockout mice maintained on a high Ca2+ diet were mated at 8 weeks of age. (A-C) Litter size (A), pup survival to weaning (B) and growth after weaning (C) were monitored for both male and female offspring. (D) Serum estradiol was measured by radioimmunoassay in virgin females. Results are mean±s.e.m. (n=7-8); no statistically significant differences were observed between the genotypes.