Fig. 7.

Sensory epithelia are disrupted in cls/sox10 mutants. Confocal images (projected Z sections) of FITC-phalloidin-stained ears to show sensory patch defects in cls^t3 mutant embryos. The age in hpf is shown for each panel. (A–H) Initial hair cell development at 28–30 hpf in both the anterior (A,C,E,G) and posterior (B,D,F,H) maculae is relatively normal in cls/sox10 mutants. (I) By 51 hpf, there are 10–20 hair cells in the WT anterior macula (arrowhead) and slightly fewer in the posterior macula (arrow). (J–L) Three examples of a cls/sox10 mutant ear at 51 hpf. The anterior macula (arrowheads) has relatively normal numbers of hair cells, but is misplaced medially; the posterior macula (arrows) has reduced numbers of hair cells. (M) In WT ears at 60 hpf, the two maculae are clearly distinct in shape and position in the vesicle (arrowhead, anterior macula; arrow, posterior macula). (N–P) Three examples of a cls/sox10 mutant ear at 60 hpf, focused on the medial wall of the vesicle. Separate maculae are no longer discernible. (Q) A lateral plane of focus at 60 hpf in a WT ear reveals hair cells in the three cristae (asterisks). (R–T) Three examples of cristae in cls/sox10 mutant ears at 60 hpf. Anterior and posterior thickenings are evident (asterisks), with variable numbers of hair cells. Right hand asterisk in (T) shows a possible lateral crista. (U,V) Sensory patches in WT and cls/sox10 mutant ears at 72 hpf. The asterisk in (V) shows a possible anterior crista. (W,X) Sensory patches in a 5 dpf WT (W) and a 6 dpf cls/sox10 mutant (X). The asterisk in (X) indicates unidentifiable crista. Panels (A–T) are lateral views with anterior to the left; (U) and (V) are dorsal views of the left-sided ears (anterior to the top); (W) and (X) are dorsal views of right-sided ears (anterior to the top). Bars, 25 μm.