Extended Data Fig. 7: Rac1 polarity gradient perturbation using optogenetics and compromising cell–cell adhesion strength by EGTA treatment.
From: The role of single-cell mechanical behaviour and polarity in driving collective cell migration
a, b, Time evolution of PBD signal in cells after homogeneous photoactivation of TIAM. Post activation, TIAM begins to localize at cell membrane. Within 5 minutes of the photoactivation, the PBD gradient flattens in cell indicating the loss of Rac1 polarity in the cell (n=11, from 7 cells). Intensity is measured along the dashed yellow line as indicated in representative panel a. Scale bar: 20 µm. c, Phase contrast imaging shows the loosening of cell–cell junctions after EGTA treatment. Exposed cryptic lamellipodia of migrating cells are marked by white arrowheads after cell–cell junction loosening. The dashed white arrows indicate the direction of rotation. d, Representative displacement kymograph of phase contrast imaged cells traced along the circumferential midline of the ring track before and after EGTA treatment (2 mM) (white dashed line indicates the time of EGTA addition ~ 20 h). e, Coordination parameter of rotating cell rings, before and after EGTA treatment (black dashed line indicates the time of EGTA addition, 20 h) (n=40, m=1). All error bars indicated are standard deviations. All scale bars unless mentioned specifically: 50 µm.
