Fig. 2.

Whole-mount X-gal staining of Kcna10^+/+ and Kcna10^TM45/TM45 inner ears. Scale bars in rows 1, 3, 5, and 7 represent 20 μm. Scale bars in rows 2, 4, 6, and 8 represent 200 μm. Inner ears of Kcna10^TM45/TM45 at E18.5 (rows 1 and 2), P17 (rows 3 and 4), P75 (rows 5 and 6), and Kcna10^+/+ P17 (rows 7 and 8) were stained with X-gal for beta-galactosidase activity. At E18.5, outer hair cells show no expression at any turn of the organ of Corti (3 arrowheads). Inner hair cells (single arrow) express beta-galactosidase in a base to apex gradient, with the strongest expression level at the basal turn (top right box), and almost no expression discernible at the apical turn (top left box) of the organ of Corti. Sensory epithelia in the utricle, ampullae, and saccule express beta-galactosidase (row 2). At P17, all inner hair cells show expression. In outer hair cells, expression occurs in a gradient with strongest expression levels of beta-galactosidase in the apical turn (row 3), and faint expression in the basal turn (row 3, column 3). The signal in the sensory epithelia cells in the vestibular organs remains consistent with E18.5 expression (row 4). This expression pattern remains consistent up to P75 (rows 5 and 6). No beta-galactosidase expression is evident in wild type controls (rows 7 and 8).