Fig. 3

Fig. 3

Wnt signaling is reduced in wls mutants. (A–H) The c186 mutation was introduced into a transgenic reporter of canonical Wnt signaling, Tg(7xTCF-Xla.Siam:GFP)^ia4 (Moro et al., 2012). At 30 hpf, (A,B) WT siblings show robust GFP labeling in the dorsal diencephalon, midbrain–hindbrain boundary and otic vesicles compared to (E,F) c186 mutants (A, E lateral views, B, F frontal views). By 60 hpf, GFP labeling is also found in the pectoral fins and jaw of (C, D) WT embryos and is reduced in (G,H) c186 mutants (C, G lateral views, D, H dorsal views). (I,J) GFP labeling from Tg(7xTCF-Xla.Siam:GFP)^ia4 colocalizes with dbx1b expression in the presumptive habenulae at 27 hpf (single section) and 35 hpf (maximum projection of 15 sections at 0.3 µm) (K,M) WT and (L,N) c186 mutant embryos were assayed for expression of the Wnt-responsive genes (K,L) lef1 and (M,N) axin2. Bilateral lef1 expression domains in the dorsal diencephalon (arrows in K) are absent in wls mutants at 4 dpf, as are axin2 transcripts in a similar region of the brain (arrow in M). Expression of axin2 is also reduced in the developing jaw and otic vesicles of (N) wls mutants. (K,L dorsal, M,N lateral views). Scale bar=100 µm for A–H and K–N and 50 µm for I,J.