Fig. 1. Expression of Shh, Ptch1, Gli1, Gli2, Gli3, Bmp4 and Hoxd13 during external genitalia development. (Top) Embryonic GT (genital tubercle) development in mice; red regions indicate the urogenital sinus (left) and the GT (middle and right). (A,B) Shh is initially expressed in the epithelium of the outermost part of urogenital sinus at 10.5 dpc. (C,D) At 11.5 dpc, Shh expression is mainly localized to the distal region of the urethral epithelium. (E,F) Shh is broadly expressed in the urethral plate epithelium in the GT from 12.5 to 14.5 dpc. Ptch1 (G), Gli1 (H), Gli2 (I), Gli3 (J), Bmp4 (K) and Hoxd13 (L) are expressed in the mesenchyme of developing GT at 13.5 dpc. E,G-L are ventral views, B,D are transverse sections and F is a coronal section. Scale bars: 250 µm in A,C; 62.5 µm in B,D,F; 312.5 µm in E,G-L.
