Figure 4.

Effects of overexpression of twinfilin 2 on cochlear hair cells. A, Hair cells were transfected with a bicistronic expression vector for twinfilin 2 and EGFP (green). Shown is a representative pair of transfected and untransfected inner hair cells. F-actin was visualized with TRITC-conjugated phalloidin (red). Cochleae were dissected at P3–P4 and transfected after 1 d in vitro (DIV), and images were taken at 2–3 DIV. B, Control hair cell transfected with a vector expressing only EGFP (green). C, Individual tall stereocilia lengths were averaged for each transfected hair cell and its untransfected neighbors and average length reductions are shown (mean ± SEM, n = 9 for twinfilin 2, n = 8 for controls). Statistical analysis with an unpaired one-tailed t test yields a significant change of p < 0.0005. Scale bars: 5 μm.