|
Fig. S3 Wnt signaling is not required for DFC specification, KV formation or apical-basal polarization of KV cells. (A-D) DFC specification was assessed by sox17 levels at the bud stage. Induction of Dkk1 (B) or DFC-targeted injection of 4 ng of fzd10 MO (D) did not alter sox17 expression compared with controls (A,C). (E,F) KV cell maintenance was evaluated by sox17 levels at 6 somites. Induction of Dkk1 (F) did not affect sox17 expression relative to controls (E). (G,H) KV formation was normal in embryos injected with 4 ng of fzd10 MO (H) compared with controls (G). Shown are ventral (A-D) and dorsal (E-H) views of the tail bud region. (I) Activation of Dkk1 or DFC-targeted injection of fzd10 MO had no effect on the expression of ZO1 (an apical marker of KV cells). Shown are the tail bud region immunostained using antibodies against acetylated tubulin (green) and ZO1 (red) at 10 somites. Tg(hsp:dkk1-GFP) embryos were heat shocked at 60% epiboly for 30 minutes (Dkk+) or 60 minutes (Dkk++) to induce Dkk1 expression. Scale bar: 5 μm. a, anterior region of KV; p, posterior region of KV.