Fig. 3. Hh signals are required for primary motoneuron induction. Dorsal views of flat mounted preparations of islet1 expression in wild-type (A); smu mutant (B); cyc;flh double mutant (C) and cyc;flh;syu triple mutant (D) embryos at 11-12 h (five to six somites). At this stage, primary motoneurons (pmns) normally form two rows in the median neural plate and Rohon Beard (RB) sensory neurons are visible at the lateral edges of the neural plate. The arrow demarcates a single primary motoneuron in the triple mutant embryo in D. Scale bar: 250 µm.
