Fig. 3. CheWnt3 is required first to activate the canonical Wnt pathway and then to restrict it to the oral pole. Activation of the canonical Wnt pathway in control Clytia embryos (A) and embryos derived from eggs injected with Wnt3-MO (B) or Wnt3 RNA (C) were visualised by injecting eggs prior to fertilisation with RNA encoding a β-catenin-Venus (GFP) fusion protein and visualised at early blastula (128-cell/4.5 hpf), mid-blastula (6.5 hpf) and early gastrula stages. Scale bars: 40 µm.