Fig. 1

Fig. 1 Canonical Wnt signaling regulates proliferation and patterning in the developing spinal cord. (A) Expression of top:dgfp, a β-catenin-dependent reporter, is widespread in the neural keel (dotted line) at 15 hpf, with a dorsal bias. (B) Expression of top:dgfp is restricted to the dorsal spinal cord at 24 hpf. (C) Immunofluorescence of unphosphorylated β-catenin is localized to the dorsal spinal cord at 24 hpf. (D) Expression of wnt1 is found in the roof plate of the spinal cord at 24 hpf. (E, F) Immunostaining for phospho-histone H3 is reduced at 24 hpf following Dkk1 overexpression at 12 hpf. (G) The mitotic index is reduced in dorsal, intermediate and ventral domains following Dkk1 overexpression. *p < 0.05 by T-test; error bars indicate ± SEM. (H, I) Expression of radar and (J, K) msxc is eliminated following Dkk1 overexpression. (L, M) Expression of pax3 is reduced in Dkk1-expressing embryos. (N, O) Expression of dbx2 shifts into the dorsal domain in Dkk1-expressing embryos. (P, Q) Expression of nkx6.2 is unaffected in Dkk1-expressing embryos. (R, S) HuC/D immunostaining is unaffected in Dkk1-expressing embryos. (A–D, R, S) show 12 μm cross-sections, and (E, F, H–Q) show lateral mounts. Scale bars = 10 μm.