Movie 1

LECs undergo pulsed contractions that correlate with their behaviour. Confocal micrographs of two LECs labelled with GMA-GFP undergoing pulsed contractions. Right cell is migrating, showing a lamellipodium (cyan arrowheads), and contracting at the same time. Left cell has lost its lamellipodium, has stopped migrating and is only constricting – orange arrowheads indicate its posterior cell interface that is more flexible than the posterior interface of its neighbour, where the lamellipodium appears to stabilise the cell-cell interface through its protrusive activity. The migrating cell shows two alternating actin foci, the constricting cell shows one focus (red dots indicate foci). Red arrow, actin bundles in the back of the migrating cell. Scale bar, 10 μm. a, anterior; p, posterior; m, medial (corresponds to dorsal); l, lateral (corresponds to ventral).