title: Wounded cells drive rapid epidermal repair in the early Drosophila embryo.
abstract: Epithelial tissues are protective barriers that display a remarkable ability to repair wounds. Wound repair is often associated with an accumulation of actin and nonmuscle myosin II around the wound, forming a purse string. The role of actomyosin networks in generating mechanical force during wound repair is not well understood. Here we investigate the mechanisms of force generation during wound repair in the epidermis of early and late Drosophila embryos. We find that wound closure is faster in early embryos, where, in addition to a purse string around the wound, actomyosin networks at the medial cortex of the wounded cells contribute to rapid wound repair. Laser ablation demonstrates that both medial and purse-string actomyosin networks generate contractile force. Quantitative analysis of protein localization dynamics during wound closure indicates that the rapid contraction of medial actomyosin structures during wound repair in early embryos involves disassembly of the actomyosin network. By contrast, actomyosin purse strings in late embryos contract more slowly in a mechanism that involves network condensation. We propose that the combined action of two force-generating structures--a medial actomyosin network and an actomyosin purse string--contributes to the increased efficiency of wound repair in the early embryo.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering and Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G9, Canada Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Howard Hughes Medical Institute, Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Fernandez-Gonzalez
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Zallen
mesh_terms: D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D004331:Drosophila melanogaster / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000473:pathology; D004817:Epidermis / Q000254:growth & development / Q000473:pathology; D004848:Epithelium / Q000196:embryology / Q000254:growth & development / Q000473:pathology*; D024462:Myosin Type II / Q000378:metabolism; D062326:Re-Epithelialization / Q000235:genetics / Q000502:physiology; D014945:Wound Healing
chemical_list: D000199:Actins; D000205:Actomyosin; D024462:Myosin Type II