Figure 2.

Sliding of adjacent doublets in a split axoneme (A) One doublet slid along another and then dissociated (0.0 to 4.0 s). After reassociating (4.2 s), the two doublets remained in close apposition and bent into a circular arc (4.5 s to 5.7 s) before dissociating again (not shown). See also Movie S1 in the Supporting Material. (B) The shape was characterized by tracking the centerline of intensity along the filament contour (marked by red crosses). The tangent angle was measured between neighboring points. (C) The tangent angles are plotted as a function of arc length, starting from the base. Except at the distal end, the tangent angle increased linearly with arc length (times 5.1–5.7 s), indicating that the shape of the doublets is nearly a circular arc. The increasing slope in consecutive frames indicates that the curvature of the arc is increasing over time and approaches a final, quasi-static shape at 5.7 s. To see this figure in color, go online.