Effects of a high-cholesterol diet and quercetin supplementation on the expression of Srd5a2 in the testes of male mice. (A) Using quantitative RT-PCR, Srd5a2 mRNA levels were estimated in the testes of mice fed normal chow and a high-cholesterol diet. Quercetin (0, 25, 50, and 100 mg/kg) and finasteride (10 mg/kg) were added to a high-cholesterol diet and Srd5a2 mRNA levels were investigated in the testes. The relative quantities of mRNA were normalized to the quantity of Gapdh mRNA. The asterisks denote sig- nificant differences (***p < 0.001). The letter ‘a’ means that there is a significant difference in the expression of Srd5a2 in the group with quercetin or finasteride supplementation as compared to that in the high-cholesterol diet group. (B) Localization of Srd5a2 mRNA in the testes was detected through in situ hybridization analyses. Cross and longitudinal sections of the testes were hybridized with antisense or sense Srd5a2 cRNA probes. Scale bars represent 10 μm (the first horizontal panels and sense) and 5 μm (the second horizontal panel). Spc, spermatocyte; Spg, spermatogonium; Spt, spermatid; Spz, spermatozoa.