Fig. 2

Specific immunocytochemical labeling of radixin in avian hair bundles. (A) A hair cell of intermediate length was isolated from the chicken's cochlea and was observed with differential-interference-contrast optics. (B) Labeling of filamentous actin with phalloidin conjugated to Alexa Fluor 568 (red) produces a strong signal throughout the same hair bundle and the subjacent cuticular plate. The partial overlap of this signal with immunolabeling by anti-radixin (green) results in a yellow signal at the bundle's base. (C and D) Immunolabeling with anti-ezrin produces no signal in a hair bundle labeled with fluorescent phalloidin (red). (E and F) In a negative control experiment, immunolabeling with the anti-radixin antiserum used in B produces a negligible signal in the brush borders of isolated intestinal epithelial cells. (G and H) In a positive control experiment, immunolabeling with the anti-ezrin antiserum used in D robustly labels brush-border microvilli. The cellular nuclei in F and H are weakly stained with TO-PRO-3 iodide (red). (Scale bar in G, 5 μm; applies to all images.)