Fig. 2. Wnt signaling is sufficient to inhibit Six3 expression and is required for Irx3 expression in headfold explants. (A-H) Headfold explants were cultured in the presence or absence of Wnt3a, Dkk1 and cki7, and Six3 or Irx3 expression assayed by in situ hybridization. Representative headfold explants are shown following culture and in situ hybridization for Six3 (A-D) or Irx3 (E-H). n=the number of explants tested per condition. Scale bar: 100 µm.