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Figure 4. Effects of Xwnt8 loss-of-function on expression of Hoxd1, Hoxa1, Hoxb1, Hoxb4, Hoxd4, and Hoxc6, as well as Otx2. Embryos were injected into the animal hemisphere at the two-cell stage with 32 ng of MOXwnt8 per cell and analyzed by whole-mount in situ hybridization. Injected embryos are shown at the bottom of each panel, control embryos are shown on top. Shown are vegetal views with dorsal to the top, except when indicated. A: Expression of Hoxd1 is down-regulated by MOXwnt8 injections, shown are stages 11 (left side of the panel) and stage 12.5 (right side of the panel). B: Expression of Hoxa1 is also down-regulated by the MOXwnt8 at stage 11 (left side of the panel), but it is not visibly affected at stage 13 (right side of the panel). C: Hoxb1 presents a shrinking expression domain upon loss-of-function at stage 13. D: Expression of Hoxb4, shown at stage 11 (left side of the panel) and stage 13 (right side of the panel), is down-regulated in some embryos by Xwnt8 loss-of-function, although in other cases they appear unaffected (see one example of each at st. 13). E: Hoxd4 is down-regulated by the MOXwnt8; shown are stages 11 (left side of the panel) and 13 (right side of the panel). F: Expression of Hoxc6 is up-regulated by Xwnt8 loss-of-function on the dorsal side of the embryo; shown are stages 10.5, where views are lateral with dorsal to the left and the blasopore down (left side of the panel) and 12 (right side of the panel). G: Dorsal to ventral sections of the embryos are shown; the plane of sectioning is depicted by the dotted line in the insets on the bottom left corner. H: Finally, Otx2 expression is increased by MOXwnt8 injections at stage 10.5 (embryos were slightly turned so that the dorsal expression domain could be better seen; the blastopore remains at the bottom). |
