Fig. 4. Ehh is less effective than Shh and Twhh for primary motoneuron formation. Lateral views of islet1 + islet2 expression (both in blue) in wild-type embryo at 24 h (A); cyc;flh double mutant at 24 h (B); flh;syu double mutant at 18-19 h (C); and cyc;syu double mutant at 18-19 h (D). Scale bar: 50 µm.