Figure 3. IHC hair bundle height in adult Eps8 mice.

(A) Transmission electron micrographs (TEM) of apical-coil IHCs from wild type (control) and Eps8 knockout (KO) adult mice (P22–P35) showing hair bundles in radial semi-thin sections. Semi-thin sections were used to maximize stereocilium length within a single section but do not allow clear visualization of finer structures such as tip links. Note the four rows of stereocilia in the control labeled: tall (T), intermediate (I), and two shorter rows (S1, S2). The knockout hair bundle is shown at the same magnification in the inset. Equivalent rows (T, I, S1, and S2) are identified by location across the hair bundle; an additional short row (S3) is also present. In the knockout hair bundle, portions of two overlapping tall stereocilia are visible (arrowhead); note that the tips (e.g. height) of these two overlapping stereocilia were similar. Scale bars: 1 µm. (B) Heights of stereocilia (mean ± s.d., number of stereocilia measured from 3 knockout and 4 control IHCs is shown above the bars). Asterisks indicate statistical significance. (C) Reduction (%) in stereocilia height in knockout IHCs compared to those of control cells.