Fig. 10. Cdc7^–/–tg/tg mice exhibit normal body weight and restored spermatogenesis. (A) Growth curve of wild-type, Cdc7^+/–, Cdc7^+/–tg, Cdc7^–/–tg and Cdc7^–/–tg/tg mice. Mice were weighed at intervals and plotted against age in days. (B) The level of Cdc7 protein in testes from mice with the indicated genotypes. Significant recovery of the Cdc7 protein level was observed in Cdc7^–/–tg/tg testes. L and S denote two alternative spliced forms of murine Cdc7 protein. (C) Histological analyses in Cdc7^+/–tg (left) and Cdc7^–/–tg/tg (right) testes. Cdc7^–/–tg/tg testes contained considerable numbers of spermatozoa (S). Scale bars, 50 µm. See Figure 3F for comparison.