Fig. 2. MIS regulates MMP2 expression in the Müllerian duct. (A) In situ hybridization shows both MMP2 and MISIIR expression in Müllerian mesenchyme, which surrounds the Müllerian duct (M) in E13 male genital ridges. At E14, MMP2 and MISIIR are detected in a narrow ring surrounding the regressing Müllerian duct (M). (B) MMP2 message is detected in the Müllerian mesenchyme of male Amh+/– ridges at E13 and E14, but not in male Amh–/– genital ridges. MMP2 expression is still detected in the coelomic epithelium (CE) of these male Amh–/– ridges. In the E14 Amh–/– panel, owing to a difference in the plane of section, the Müllerian duct appears further away from the coelomic epithelium than in the other micrographs. The absence of MMP2 staining in the E14 Amh–/– Müllerian mesenchyme and its persistence in the coelomic epithelium illustrates that MMP2 expression is independently regulated in these two tissues; the Wolffian duct is out of the frame of the photomicrograph. The dotted circles indicate the position of the Müllerian ducts.
