Fig. 2. Temporal limit for the Wnt/ß-catenin signaling requirement. Foxd3-positive neural crest cells, identified by anti-Foxd3 primary antibody (red), flank the neural plate after heat activation at bud (A), 3-somite (B), and 6-somite stages (C). Transgenic embryos show significant loss of Foxd3 expression upon heat activation of hs-Tcf (green) (D,E), while Foxd3 expression is comparable to that of wild-type siblings after induction at 6-somites (F). All images are dorsal views, anterior to top, of stacked 10X confocal series after fixation at 3-somites (A,D) or 10-somites (B,C,E,F). Expression of the transgene is shown in the insets (D,E,F).