Two Rok-RNAi LECs showing impaired contractile behaviour and actin flows in the back of their neighbours. Detail confocal micrographs of two LECs during late migration, F-actin labelled with GMA-GFP. Cells generate lamellipodium in the front (cyan arrowheads) and show a not very dynamic apicomedial network, which does not generate clear foci, but shows only some diffuse activity. The cell on the right and its right-hand neighbour create contractile flows in their back (cyan asterisks), which lie underneath the lamellipodium of their left-hand neighbour (orange line highlights the overlapping region of the cell on the right). Scale bar, 10 μm; a, anterior; p, posterior; m, medial (corresponds to dorsal); l, lateral (corresponds to ventral).