Fig. 8 mol-/- embryos exhibit cranial motoneurone induction and patterning defects. Lateral (A,B) and dorsal (C-J) views of wild-type (WT) and mol-/- embryos labelled with various antibodies and RNA probes (indicated bottom right) to reveal cranial motoneurones and their axons. The unlabelled arrow in F shows a few Vp neurones in the mol-/- embryo. Arrows in G and H show the trochlear decussation in wild type (G) and its absence in mol-/- (H) embryos. The arrow in J indicates foxa1 expression retained between the two bilateral Va nuclei of the mol-/- mutant. III, oculomotor nucleus; IV, trochlear motor nucleus; Va and Vp, anterior and posterior components of the trigeminal motor nucleus; VII, facial motor nucleus; X, vagal nucleus cb, cerebellum; pc, posterior commissure; R, rhombomere.