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Fig. S6 TOP:GFP expression in zic morphants. As zic1 was recently shown to regulate wnt genes (Merzdorf and Sive, 2006), we asked if Wnt signaling was affected in zic2a-zic5 morphants by assaying expression of a Wnt reporter transgene. This analysis, although not quantitative, suggested that Wnt signaling was not altered in zic morphants. (A) TOP:GFP transgene contains a wnt/β-catenin responsive synthetic promoter (TOP) composed of four consensus Lef-binding sites (blue stars) and a minimal promoter sequence, driving a destablized gfp reporter (Dorsky et al., 2002b). TOP:GFP transgenic embryos were injected with 2 MOC+5MOC (C,E), and gfp expression was compared with uninjected embryos (B,D) at 20-somites or at 25 hpf. (B,C) At 20-somites, TOP:GFP expression in morphants (n=24) was comparable to that in uninjected embryos (n=18). (D,E) At 25 hpf, the TOP:GFP expression domain was misshapen in morphants (n=20/82), probably as a result of morphological defects, as compared with controls (n=18). However, there was no significant expansion or reduction in TOP:GFP expression. All embryos are positioned in lateral view, with anterior to the left.