Fig. 2

LE cells of partial-thickness wounds form lamellipodia but lack signs of purse-string mechanisms. (A) Puncture wound in fin of 3-day-old embryo shows circular, colocalized actin (left panel) and phosphorylated non-muscle myosin (middle panel) at the wound margin. Images are maximum projections, insets single z-planes in the centre of the wound. (B) Puncture wound in trunk of adult, with cortical p-myosin in adjacent keratinocytes, including the sides facing the wound (arrow). (C,D) Adult partial-thickness wound; actin fibres are present within the protruding lamellipodia (red), p-myosin is accumulated at the posterior of LE cells (magenta, arrow). (E-G) Live confocal images of partial-thickness wound of Tg(actb2:hras-egfp), Tg(krt4:mCherry) double transgenic. Lamellipodia are formed at the LE by inner keratinocytes (green), whereas superficial cells (red) remain further back (E,F). (G) Single plane confocal images, revealing the enormous lamellipodial size relative to the cell body of an LE keratinocyte (upper panel). Inner keratinocytes behind the LE also show restricted protrusive activity (G, bottom panel; lamellipodium, arrow). (H) Stills from a time-lapse movie at indicated relative time points. Rarely, usually when encountering an obstruction, LE cells undergo more pronounced EMT-like changes and retain only limited contact with following cells. Asterisks indicate the same blood vessel. Scale bars: 20µm in A-H; 10µm in insets in A.