Figure 1

Effect of EGF on spermatogonial proliferation and their differentiation to primary spermatocytes. (A and B) Stimulatory effect of EGF on spermatogonial proliferation. Testicular fragments containing speramatogonial stage were cultured for 1 week in the absence or presence of either FSH or various doses of EGF indicated. (A) Immunohistochemistry for BrdU incorporation in the sections of the fragments treated without (Control) or with either FSH or EGF. (B) Spermatogonial proliferation was determined by counting BrdU positive cysts among live ones in at least 3 sections. *, P < 0.05. (C) No effect of EGF on spermatogonial differentiation. Testicular fragments containing spermatogonial stage were cultured for 2 weeks in the absence (Control) or presence of either FSH or EGF, followed by staining with hematoxylin/eosin. Primary spermatocytes are surrounded by black dashes.