Movie 4

Cytoskeletal architecture and pulsatile activity of a constricting LEC. Sqh::GFP labels actin foci, actin bundles and cell-cell interfaces during constriction. Radially organised actin bundles (red arrowheads) connect the apicomedial network to the cell cortex. The contractile event begins in the cell periphery and then moves towards the cell centre. Red ellipsoids indicate movement of fluorescence signal towards the cell centre. Red dot shows actin focus at full contraction. Scale bar, 10 μm; a, anterior; p, posterior; m, medial (corresponds to dorsal); l, lateral (corresponds to ventral).