Fig. 6. Porcupine/palmitoylation regulates Wnt-induced proliferation in the chick neural tube. Embryos were electroporated in the neural tube as described in Materials and methods. GFP-positive embryos were harvested for analysis 24 hours post-electroporation. Embryos were fixed, cryosectioned and immunostained with anti-phosphohistone H3 (red), which marks cells in late G2/M phase. (A) A section from a representative embryo electroporated with mPorcD. The right side of the neural tube has been electroporated (experimental), whereas the contralateral side serves as a control. (B) The ratio of experimental/control proliferation indices for embryos electroporated with Wnt1, Wnt3a, mPorcD, mPorcD(H341Q), Wnt1(C93S) and Wnt3a(C77S). Error bars show the standard error. N, number of embryos analyzed for each data point; n, number of sections analyzed. ^*, Significantly different from the control (P<0.05). nt, neural tube; no, notochord.