Fig. 4

Tcf/Lef-miniP:dGFP transgenic zebrafish expressed d2EGFP in various tissues during juvenile growth processes. (A–D) d2EGFP protein expression in 1 mpf Tcf/Lef-miniP:dGFP transgenic zebrafish. Lateral (A), dorsal head (B), ventral head (C), and lateral liver (D) views of transgenic fish, with the anterior side to the left. d2EGFP-expressing cells were visualized by fluorescence microscopy. Scale bar, 200 μm. Nose (no), retina (re), tectum (te), gill, pectoral fin (pf), skin (sk), pelvic fin (pf), median fin mesenchymal cell (mf), anal fin (af), dorsal fin (df), median fin fold (mff), and caudal fin (cf). We could not distinguish d2EGFP expression in the liver or skin of intact fish (data not shown). Therefore, the skin was peeled away to clearly visualize expression in the liver (D). (E) XAV939 or IWR-1 treatment reduced the β-catenin protein level and Tcf/Lef-miniP:dGFP reporter activity. The panels show left-side head or trunk views of 1-mpf Line-2 juveniles treated with DMSO or 10 μM XAV939 or 10 μM IWR-1 for 24 h, with the anterior side to the left. d2EGFP-expressing cells were visualized by fluorescence microscopy (lower panels). Bright-field (BF) images are shown in the upper panels. Scale bar, 200 μm.