Node movements in wild-type and cofilin mutant cells. Negative-contrast fluorescence micrographs of cells with nodes marked by Rlcp-3GFP at 25°C. Numbers are time in seconds on an arbitrary time scale. Bars, 5 µm. (A and B) A DIC image of each cell is shown on the left with the region of interest highlighted by dashed lines. Montages show time series of single confocal sections. (A) This wild-type cell condensed nodes into a ring (arrow) in 480 s from the beginning of this series. The interval between each frame is 20 s. Also see Video 5. (B) The nodes in this adf1-M3 cell formed one big clump and a small clump (empty arrows). Also see Videos 6 and 7. (C) Kymographs of node movements in an adf1⁺ cell (from A) and an adf1-M3 cell (from B). Kymographs were constructed from time series of projections of the top confocal section of the regions of interest (dashed rectangle) onto lines either perpendicular (left) or parallel (right) to the long axis of the cell. Over time nodes formed either a contractile ring (arrow) or clumps (empty arrows). (D and E) Motions of nodes (closed head arrows) relative to clumps (open head arrows) in adf1-M2 cells. Boxes outline regions of interest (ROI) in maximum intensity projections of a Z-series of fluorescence micrographs of whole cells (dashed lines) at the start of the time series. Kymographs were generated as in C. (D) A node merged with a nearby clump of nodes. The ROI was rotated 90° clockwise for viewing. (E) Two nodes merged with each other before merging with a clump of nodes.