Fig. S1

Fig. S1

Hedgehog/Smoothened signaling initiates in osteoblast progenitors before expanding to neighboring basal epidermal cells during the course of fin regeneration. (A-I) Immunostaining showing Runx2 (magenta) and Kaede (green) protein in fin sections prepared from ptch2:Kaede fish at 24 (A-C), 36 (D-F), and 48 (G-I) hours post-amputation (hpa). Ptch2:Kaede is first expressed in Runx2⁺ pObs at 24 hpa and is excluded from all other cell types. By 36 hpa, nearly all Runx2⁺ cells co-express Kaede. White arrows indicate Runx2⁺/Kaede⁺ pObs. By 48 hpa, ptch2:Kaede is also expressed in the basal epidermis adjacent to Kaede⁺/Runx2⁺ pObs. Green arrows point to Kaede⁺ basal epidermal cells. For panel I, the region bound by a dashed white box is shown in higher magnification in the inset panel. Amputation planes are indicated with a dashed yellow line. Hoechst-stained nuclei are blue in all overlay images. Scale bars: 50 μm.