Neural derivatives of NC are affected by the mosm188 mutation. A,B: In wild types (A) at 24 hpf, sox10 is expressed in late specified pigment and neural precursors migrating ventrally from the dorsal aspect of the neural tube, in the otic vesicle (ov), and in the preotic and postotic clusters of glial precursors (arrowheads). In the mosm188 mutant embryos (B), the otic vesicle expression is unchanged, while expression in all other domains is greatly reduced. C,D: Anti-Hu staining in the trunk of 4-dpf embryos. The wild-type pattern of the segmentally organized DRGs (arrows), enteric neurons (ENS), and sympathetic neurons (sn; arrowheads) is shown in C. In the mosm188 mutant (D), there are only a few scattered DRGs (arrows) and sympathetic neurons (arrowheads). An asterisk marks the area devoid of enteric neurons in the digestive tube. E,F: The reduction of the sympathetic neuron precursors in mosm188 mutants is already evident at 50-hpf embryos stained with the dopamine beta hydroxylase (dbh) riboprobe. G,H: The enteric neuron precursors migrate into the gut tube at 36 hpf as marked by ret-positive cells in wild-type embryos (G). The ret expression is greatly reduced in mosm188 mutants (H). DRG, dorsal root ganglia; ENS, enteric nervous system; ov, otic vesicle; sn, sympathetic neurons.