Fig. 9. ß-catenin regulates sqt and cyc, and requires sqt to induce gsc. Wild-type embryos were injected with ß-catenin (A,C,E) or lacZ (B,D,F) mRNA, and processed for in situ hybridization. Overexpression of ß-catenin induces cyc expression at 6 h (A), but not at 4 h (E, sphere) or 5 h (C, 40% epiboly). (G-J) Analysis of gsc expression at 5 hours in embryos from a sqt^+/- intercross injected with ß-catenin or lacZ mRNA. ß-catenin mRNA (G), but not lacZ mRNA (H), can induce ectopic gsc expression in wild-type embryos. ß-catenin mRNA does not induce normal levels of gsc expression in sqt^-/- mutants (I), but ectopic patches of weak gsc are often observed in these embryos, indicating that ß-catenin has some activity in sqt mutants (arrows, I). ß-catenin induces sqt expression at 3.3 h (K), but not at 5 h (M, 40% epiboly). Animal views; dorsal towards right when apparent.