title: Tension regulates myosin dynamics duringDrosophilaembryonic wound repair.
abstract: Embryos repair epithelial wounds rapidly in a process driven by collective cell movements. Upon wounding, actin and the molecular motor non-muscle myosin II are redistributed in the cells adjacent to the wound, forming a supracellular purse string around the lesion. Purse string contraction coordinates cell movements and drives rapid wound closure. By using fluorescence recovery after photobleaching inDrosophilaembryos, we found that myosin turns over as the purse string contracts. Myosin turnover at the purse string was slower than in other actomyosin networks that had a lower level of contractility. Mathematical modelling suggested that myosin assembly and disassembly rates were both reduced by tension at the wound edge. We used laser ablation to show that tension at the purse string increased as wound closure progressed, and that the increase in tension was associated with reduced myosin turnover. Reducing purse string tension by laser-mediated severing resulted in increased turnover and loss of myosin. Finally, myosin motor activity was necessary for its stabilization around the wound and for rapid wound closure. Our results indicate that mechanical forces regulate myosin dynamics during embryonic wound repair.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9.|Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Ontario, Canada M5G 1M1.
authors.forename: Anna B
authors.initials: AB
authors.lastname: Kobb
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9.|Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Ontario, Canada M5G 1M1.
authors.forename: Teresa
authors.initials: T
authors.lastname: Zulueta-Coarasa
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9 rodrigo.fernandez.gonzalez@utoronto.ca.|Ted Rogers Centre for Heart Research, University of Toronto, Toronto, Ontario, Canada M5G 1M1.|Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5.|Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
authors.forename: Rodrigo
authors.identifier: 0000-0003-0770-744X
authors.initials: R
authors.lastname: Fernandez-Gonzalez
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D024462:Myosin Type II / Q000378:metabolism*; D010766:Phosphorylation; D055550:Protein Stability; D014945:Wound Healing
chemical_list: D029721:Drosophila Proteins; C495593:Sqh protein, Drosophila; D024462:Myosin Type II
keywords: Cell mechanics; Cytoskeletal dynamics; Drosophila; Embryonic wound healing; Fluorescence recovery after photobleaching; Laser ablation