Fig. 2.

Foxn4-mediated equilibrium between Ascl1 and Neurog expression is essential for generating V2 interneuron diversity. (A-C) There is almost complete overlap between Ascl1 and Foxn4 expression in the p2 domain at E10.5-E12.5. (D-H′) In spinal cords of E11.5 Foxn4 mutant embryos, there is complete loss of Ascl1 (D,D′) and Dll4 expression (G,G′) in the p2 domain, whereas normal expression of Neurog1 and Neurog2 is observed (E-F′). Arrows in G,G′ indicate Dll4 expression in blood vessels. Schematic representation in H,H′ shows that Neurog expression is insufficient to induce Dll4 expression in the absence of Ascl1 and Foxn4. Scale bars: in F′, 11.8 μm for A-C; in F′, 20.7 μm for D-F′; in G′, 10 μm for G,G′.