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Fig. 8
Figure 8. Trilobite (vangl2) mutants are highly sensitive to canonical signaling.
Injection of a low dose (5pg) of wnt8a into embryos from a tri+/- X tri+/- parental cross results in extremely dorsalized embryos and significant lethality (A–D, I). Different classes of phenotypes are shown in (A–D) with an uninjected wild-type sibling shown at the top in (A), and an uninjected tri mutant shown at the top in (B) for comparison. Addition of Nkd1 is capable of fully suppressing the wnt8a overexpression lethality and dorsalization (I). n values are for all genotypes. In contrast to the extreme phenotypes seen at 1 dpf, there is no effect of Wnt8a on the early organizer (E–H) shown by expression of gsc (E, F) and bozozok (boz) (G, H) an early and direct transcription target of maternal Wnt signaling. (J–M) Injection of vangl2 MO does not alter the expression of gsc (K), nor does the low level of wnt8a (M). However, co-injection of vangl2 MO and wnt8a results in ectopic gsc expression about 2-5% of the time (red arrowheads, n= 21).