Fig. 7. Fz3 and Fz6 localization in mouse inner ear sensory epithelium. (A) Immunolocalization of Fz3 (green) in the organ of Corti at P0. Actin bundles are stained with phalloidin (red). IHC, inner hair cells; OHC1, inner row of outer HCs; OHC2, central row of outer HCs; OHC3, outer row of OHCs. (B) In the vestibular system, Fz6 (green) is expressed in supporting cells and sensory neurons. In the Fz3^-/- crista, sensory hair bundle kinocilia orient to the right, as indicated by the hole on the actin-rich cuticular plate (phalloidin, red), which covers much of the apical face of the sensory neurons. Fz6 localizes preferentially on lateral faces that orient perpendicular to the axis of the sensory hair bundles. (C-E) WT:Fz6^-/- mouse embryo chimeras and Fz6 protein localization. (C,D) Organ of Corti from a WT:Fz6^-/- embryo chimera immunostained with anti-Fz6 (red) and anti-ß-galactosidase (green) to visualize nuclear ß-galactosidase encoded by Fz6^-/- (lacZ knock-in) cells (asterisks). Phalloidin (blue) stains actin bundles. ß-galactosidase expression varies among Fz6^-/- cells. The nuclei (D) are present in a deeper plane than the apical edge of the cells, where Fz6 accumulates (A). (E) An enlargement of the right corner of C, showing Fz6 punctate intracellular accumulation only in WT cells. Reproduced with permission from Wang et al. (Wang et al., 2006b).