Fig. 4.

Contributions of active Wnt/β-catenin, repression in the absence of Wnt signals, and FGF signaling in the marginal zone. (A) RNA in situ hybridization on mid-gastrula-stage embryos incubated in either DMSO or 50 µM SU5402 at stage 10.5 until collection. (B) Embryos were treated as in A, but collected in Trizol for RNA extraction and subsequent qPCR. Data shown is from three replicates of single embryos. Data are mean±s.d. *P<0.05; **P<0.01; Student's t-test. (C) Embryos were either incubated in DMSO or 50 µM SU5402 starting at stage 10.5 until dissection at stage 11.5. qPCR data from dorsal, lateral or ventral equatorial dissections. Results are from a single experiment using 10 embryos for each condition. (D) In situ hybridization on gastrula-stage embryos injected with 100 pg dkk1 in all four blastomeres of a four-cell-stage embryo. Arrows are pointing to the ventral domain. Sections were made by bisecting embryos. (E) In situ hybridization on gastrula-stage embryos injected in both ventral blastomeres at the four-cell stage with β-catenin and β-gal tracer. UC, uninjected control embryos.