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Fig. 3. Canonical Wnt signaling regulates expression of RhoV in the neural crest. (A) Two-cell stage embryos were injected in one blastomere with 100 pg of plasmid DNA encoding mouse Wnt-1. DNA was used instead of mRNA to reduce expression and avoid axis duplication. (B) Alternately, embryos were injected with 1 ng of mRNA encoding human GSK3β. At this level, expression of GSK3β has no effect on mesoderm development (data not shown). At neurula stages, embryos were analyzed by whole-mount in situ hybridization for the neural crest markers Sox9 (a), Snail (b) and RhoV (c). Expression of all neural crest markers and RhoV was laterally expanded upon canonical-Wnt signaling activation, and conversely down-regulated upon Wnt inhibition. In all panels, the lineage tracer β-galactosidase mRNA was co-injected to visualize the injected side (red staining). |
