Fig. 6. Compromised proliferation activities in regenerating Frs2^cn prostates induced by androgens. (A,B) Expression of Frs2 in the epithelium of regenerating prostates. Expression of Frs2 was assessed by in situ hybridization (A) or real-time RT-PCR (B). Data were normalized to the abundance of 18S rRNA and are expressed as mean±s.d. of at least three prostates. The background of Frs2 expression in the conditional mutants is from the stroma. Red arrows, epithelial cells; black arrows, stromal cells. (C,D) Reduced androgen-induced proliferation in Frs2^cn prostates. Androgen was restored to mice 14 days after orchiectomy to induce prostate regeneration. Tissues were harvested at the indicated days after administration of androgen. Proliferating cells were revealed by immunostaining with anti-PCNA antibody (C). Red arrows, epithelial cells; black arrows, stromal cells. (D) Representative data from the dorsolateral prostate are shown. PCNA-positive cells were scored and reported as ratios of proliferating cells to total cell numbers. Mean±s.d. values of data from at least three prostates are shown. (E) The average wet tissue weights of normal prostates before castration (Cont), 2 weeks after the operation (Cas), and 14 days after administration of androgen (Reg). Mean±s.d. values of data from three samples are shown. F/F, homozygous Frs2^flox mice; CN, Frs2^cn mice.