Figure 4. Establishment of the oral inductive territory in Nematostella.

At 10 hpf Wnt1, Wnt2, Wnt3 and WntA are the first Wnt genes to be expressed. Wnt2 expression starts as a ring excluding the presumptive pre-endodermal plate. Wnt1, Wnt3 and WntA expression starts as a patch in the presumptive pre-endodermal plate and by 14–18 hpf begins to form a ring around it. Brachyury expression is first detectable as a ring at 10 hpf. Wnt4, Dpp and Chd start to be expressed in a ring around the pre-endodermal plate by 14 hpf. On lateral views, animal/oral ends of the embryos point up. Scale bar: 100 μm.