Fig. 7

Fig. 7

The Tcf/Lef family of transcription factors was required for Wnt/β-catenin signaling activity in the midbrain, pLL, and tail bud. (A, D) Tcf/Lef-miniP:dGFP reporter activity in the dorsal midbrain (dmb) and prim-I was dependent on Lef1, Tcf7, and Tcf7l2, and this activity in the newly formed somites (so) and tail bud (tb) was regulated by Lef1 and Tcf7. Control MO, lef1 MO, tcf7 spl MO, tcf7l2 MO, or lef1 spl MO was coinjected with p53 MO into one cell-stage Line-2 embryos, as indicated. Left-side head (A) and tail (D) views of MO-injected Line-2 embryos, with the anterior side to the left. Bright-field (BF) images are shown in the upper panels. d2EGFP-expressing cells were visualized by fluorescence microscopy (lower panels). Scale bar, 200 μm. (B) Whole-mount in situ hybridization staining for lef1, tcf7, and tcf7l2 using 24-hpf (D) zebrafish embryos. Tcf/Lef mRNAs were detected in the dorsal midbrain (dmb), prim-I, newly formed somites (so) and tail bud (tb). Scale bar, 200 μm. (C) Tcf7l2 was required for midbrain development. Dorsal views of 80-hpf HuC-Kaede transgenic zebrafish embryos injected with control MO, lef1 MO, tcf7l2 MO, or p53 MO. In A, bright-field (BF) images are shown in the left panels. Kaede-expressing cells were observed by fluorescence microscopy (right panels). Broken lines indicate the tectum or presumptive tectal region. Scale bar, 100 μm.