Supplementary Figure 5: Confocal imaging of RhoA activity for cells migrating on a micropillar array.
From: Interplay of RhoA and mechanical forces in collective cell migration driven by leader cells
In all the images, the large arrows is within the finger and points to the leader cell. (A) Leader cell: the high level of RhoA activity is highlighted by arrows and is colocalized with the lamella. In the xy image (top panel), the cell contour is outlined with a dashed line. This image is taken ∼4μm above the tops of the pillars (triangle on the xz section (bottom panel)). The dashed line on the xz section outlines the lamella. (B) Enhancement of the activity at the free edge of the finger where it is colocalized with the actin cable. Top panel: xy section; bottom panel xz section. In both (A) and (B) images, the xz section are taken along the white line of the corresponding xy image. The grey box at the bottom represents a volume below the top of the pillars where imaging is not reliable. (C) at the basis of the finger, the polarity is very weak (front side and backside activities are comparable). In images (B) and (C), the top of the pillars are clearly apparent (insets). Note that image processing was optimized for FRET differences (colour differences), rather than biosensor localization (signal intensity). Representative images. 3–6 replicates from 3 independent experiments.
