Fig. 6. Ciliary reversal in response to UV application. Light was applied to the cilia at the anterior of a cell loaded with NP-EGTA in Ca²⁺-containing medium. (A) A representative result in which the distance l (see Fig. 5) is zero. This series of images are indicated in Movie 2. (B) The distance l is 6 µm. This series of images are indicated in Movie 3. Before, prior to UV application; after, following UV application. UV light was applied to the area indicated by the circle. Arrows, direction of the cilia within or outside of the area of UV application. Bars, 20 µm. (C) Relationship between the distance l and the maximum angle of ciliary reversal. Ciliary angles before (triangles) and after (circles) UV application are plotted against l.