Fig. 3

Comet-like wandering cluster displaying coordination in the direction of movement and velocity. a. Trajectory of a representative comet-like wandering cluster. Colors indicate the positions of the cluster in between hours 70 (cyan) and 200 (magenta). For more details, see Movie S2, which was extracted from Movie S1. b. Time course of changes in velocity and size of the cluster shown in panel a. Color bar on the horizontal axis is the same as shown in panel a. Arrowheads show the time when the velocity accelerated transiently. c. Trajectory of the same cluster during the first spike in velocity that peaked at hour 154 (Green). Orange represents trajectories of three other preceding clusters. It should be noted that the velocity of the cluster shown in cyan started to increase at hour 152 (panel b), when the cluster passed over a trail of a preceding cluster. From this time up to hour 156, the cluster passed over two other trails. d. Fluorescent microscopic images of RCA-120 stained cells. Magenta and cyan indicate autofluorescence of cells and stained EPS, respectively. e. Movement and morphology of a comet-like cluster wandering for 10 min. The video is provided as Movie S3. f. PIV analysis of the movement of the comet-like cluster with confocal images of autofluorescent cells. Color bars and arrows indicate trajectories of single cells within a period of 10 min (cyan to magenta) and the result of PIV analysis (velocity), respectively. The video is shown in Movie S4. g. U-shaped motion of a single filament