Fig. 3. MIS activates R-SMADs 1, 5 and 8 in urogenital ridges in organ culture. (A-E) Female urogential ridges were harvested at E14.5, directly fixed (A) or cultured for 2 hours (B), 6 hours (C), 30 hours (D-F), in the presence (B-D) or absence (E) of MIS. (F) Male urogenital ridges cultured at E14.5 for 30 hours. P-SMAD expression was detected by whole-mount immunofluorescent analysis. Arrows and arrowheads mark the expression of P-SMAD in the areas lateral and medial to the Müllerian duct, respectively. Cranial is oriented towards the top and Müllerian duct to the right of individual images. Ov, ovary; T, testis. Scale bar: 500 µm.