Fig. 2.

The minimum jasplakinolide concentration needed to stabilize filaments is >6 nm. a–c, Incubation in as little as 20 nm jasplakinolide (jas) induces a filopodial expansion, indicating stimulation of actin assembly rather than mere stabilization of F-actin, here stained with rhodamine phalloidin. Scale bar, 10 μm.d, Transmitter vesicle recycling depends on filament turnover rate (Bernstein et al., 1998) and is attenuated by preincubation in jasplakinolide >6 nm. Cells were depolarized in a 75 mm K⁺ buffer containing the fluorescent styryl dye FM1-43 (10 μm), which is used to monitor depolarization-induced vesicle cycling (Cochilla et al., 1999). g, Overlay of DIC (e) and fluorescence (f) images, showing depolarization-induced FM1-43 uptake in ciliary calyx. Scale bar, 20 μm.