Cellular Responses and Genetic Requirements of Pinch Wound Healing

<div><p>(A–D) Larvae carrying the <i>msn-lacZ</i> reporter and the indicated transgenes or mutations were pinched with a forceps to abrade a region of dorsal epidermis but leave the overlying cuticle intact. Wounded larvae were cultured for the indicated times and immunostained for Fasciclin III (red) and β-galactosidase (green).</p> <p>(A) 6 h after pinch wounding. Note the large epidermal gap (asterisk) at the wound site. Some cells at the wound margin have elongated and oriented toward the wound (arrowheads). Others have fused to form syncytia (arrow).</p> <p>(B) 24 h after pinch wounding. The epidermis has spread to close the gap. Note disorganization of epidermis and syncytia (arrows) at site of healed wound.</p> <p>(C) An <i>A58-Gal4</i> and <i>UAS-bsk^DN</i> larva 24 h after pinch wounding. Epidermal spreading is inhibited and a large wound gap remains (asterisk). However, cells at the wound margin still orient toward the wound (arrowheads) and fuse to form syncytia (arrows).</p> <p>(D) A hemizygous <i>lz^r15</i> mutant larva 24 h after pinch wounding. <i>lz^r15</i> blocks crystal cell development and scab formation at puncture wounds (<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020239#pbio-0020239-g006" target="_blank">Figure 6</a>), but no defects are observed in pinch wound healing.</p> <p>(E and F) Larvae carrying <i>msn-lacZ</i> reporter were mock-wounded (E) or pinch wounded (F), cultured for 4 h, and stained with X-gal (blue). Wounding induces reporter expression in a gradient extending out four cell diameters. The gap (asterisk) lacks a scab.</p> <p>Bar, 100 μM.</p>