Fig. 5.

Membrane protrusions require a functional actin cytoskeleton. a Representative micrographs of MCF-7 cells that express the LifeAct-mCherry fluorescent reporter and incubated or not (untreated) with CK666 or latrunculin A (LAT) at different time-points during aggregation. Cell contours and membrane protrusions were automatedly detected (white line). Scale bar: 10 µm. b Determination of the average (µ) and standard deviation (σ) aspect ratio of single cells in control (untreated; UNT), and in cells incubated with CK666 or latrunculin A (LAT). *P < 0.05; **P < 0.01; ****P < 0.0001 (Mann–Whitney non-parametric test). Each dot corresponds to the values of one cell. c Graphs showing the aspect ratio and circularity of the larger clusters (see micrographs in left panels, larger clusters are in red) in control (UNT) and CK666 or latrunculin (LAT)-treated cells after 3 h of clustering. Each dot corresponds to the values of one well. For b and c, data are from 5 independent experiments, and bars correspond to the mean ± SD. *P < 0.05; **P < 0.01; ****P < 0.0001 (Mann–Whitney non-parametric test)