Fig. 4

Effects of Six1 knockdown on early ectodermal TFs. a–j Expression of PPE (Eya1, Sox3), NC (FoxD3), neural plate (Sox3) markers and early ectodermal TFs in dorsal views of neural plate stage Xenopus embryos after injection of Six1 MO1 + MO2. Anterior is to the bottom. Control side is shown on the left and injected side on the right (as indicated by blue LacZ staining). Reductions (arrows) and increased or ectopic expression domains (asterisks) in the neural (green) and non-neural ectoderm (orange) compared with the control side (arrowheads) are indicated. Green lines highlight broadening of the neural plate and lateral displacement of NPB markers on the injected side (bright green) versus control side (dark green). Insets show alternative phenotypes. k Summary of regulatory interactions. Arrows indicate requirement of Six1 for expression of TFs (reduction after Six1 knockdown). Bars indicate requirement of Six1 for restriction of expression of TFs (increase after Six1 knockdown). Faint colors indicate less frequent phenotypes. See Additional file 1: Table S8 for numbers