Fig. 6. Wnt8 requires Vent and Vox to repress dorsal genes. (A-D) GFP in situ hybridization to embryos homozygous for the TOPdGFP transgene. (E-H) opl, pax2a and tbx6 in situ hybridization. Genotype/treatment is indicated above each panel. (A) TOPdGFP is expressed in the mesoderm. In wnt8 morphants (B), TOPdGFP is barely detectable (arrow). vent+vox MO-injected embryos display mostly wild-type TOPdGFP expression (C), but some display somewhat reduced expression (D, arrows). Arrowheads in A-D indicate the AP extent of the TOPdGFP positive domain. (E) In wild type, opl and pax2a expression domains in relation to tbx6 indicate normal neural posteriorization. In wnt8 morphants, opl is expanded posteriorly, pax2a is delayed and tbx6 is reduced (F). vent;vox mutants (G) do not display a strong AP defect, and ventral tbx6 staining is as strong as in wild-type embryos. Reducing Wnt8 in vent;vox mutants (H) results in decreased tbx6 and pax2a expression. The distance between the arrowheads in F, G and H show the degree of posteriorization. Embryos shown are at 100% epiboly, lateral view, dorsal right.