Fig. 5

BMS-833923 demonstrates that Hedgehog/Smoothened signaling is dedicated to bony ray branching during the outgrowth phase of fin regeneration. (A-J) Whole-mount images of fins from the same two sp7:EGFP fish acquired prior to amputation and at 12 and 30 days post-amputation (dpa). The fish are treated with either control DMSO or BMS-833923 at 48 and 72 hpa. (A-C,F-H) Fluorescence images showing osteoblast GFP expression in green. (D,I) Rotterman contrast images. Periodic high-contrast patches along the rays are joints. Red lines and arrows mark ray bifurcation points. (E,J) Bright-field images of Alizarin Red-stained fins collected from the same fish to visualize mineralized bone. Amputation planes are indicated with dashed yellow lines. (K,L) Wide-field whole-mount GFP fluorescence and bright-field overlay images of 5 dpa fins from shha:GFP fish following injections with DMSO or BMS-833923 at 48 and 72 hpa. Green brackets indicate the extent of epidermal shha:GFP expression along the proximal-distal axis. Student's t-test shows the 142% mean increase in the length of the shha:GFP domain is significant [n=5 control and 10 BMS-833923-treated fish (60 scored rays), P<0.0001]. Scale bars: 2 mm in A,F; 1 mm in B-E,G-J; 500 µm in K,L.