Fig. 3.

Synergistic effects of TGF-β RI kinase inhibitor and pan-Ras inhibitor during palatal fusion. Palatal shelf organ cultures were prepared using a pair of the dissected shelves from wild-type mice at E14.5, culturing for 48 h with specific inhibitor or DMSO as described below. (A) Dissected shelves were pretreated with 5, 2, 1 or 0.5 µM SB431542 or DMSO for 6 h prior to organ culture. (B) Dissected shelves were pretreated with 10 µM or 5 µM Pan-Ras-IN-1 or DMSO for 6 h prior to organ culture. (C) Simultaneous treatments with SB431542 and Pan-Ras-IN-1 at the indicated concentrations were performed 6 h prior to organ culture. Histological sections of horizontal palatal shelves were stained with Hematoxylin and Eosin (HE). Arrowheads indicate the contact region of the paired shelves in fused palatal shelves. The lower (right in B) panel displays the incidence of palatal fusion in each treatment group. Scale bars: 200 μm.