Multiple forces contribute to cell sheet morphogenesis for dorsal closure in Drosophila.

摘要: The molecular and cellular bases of cell shape change movement during morphogenesis wound healing are intense interest only beginning to be understood. Here, we investigate the forces responsible for dorsal closure with three approaches. First, use real-time time-lapsed laser confocal microscopy follow actin dynamics document changes tissue movements in living, unperturbed embryos. We label cells a ubiquitously expressed transgene that encodes GFP fused an autonomously folding binding fragment from fly moesin. Second, biomechanical approach examine distribution stiffness/tension by following response various tissues cutting ultraviolet laser. tested our previous model (Young, P.E., A.M. Richman, A.S. Ketchum, D.P. Kiehart. 1993. Genes Dev. 7:29–41) leading edge lateral epidermis is contractile purse-string provides force closure. show this structure under tension behaves as supracellular purse-string, however, provide evidence it alone cannot account In addition, there isotropic amnioserosa anisotropic epidermis. Tension may contribute closure, but opposes it. Third, role repeated ablation Our data strong both appear normal living embryos, surprisingly, neither absolutely required Finally, establish Drosophila rapidly reproducibly heals mechanical wounds, even those delivered repeatedly. During healing, recruited margins newly formed, contracts healing. This result establishes embryo excellent system investigation Moreover, observations demonstrate insect epidermal parallel vertebrate situ culture (for review see Kiehart, 1999. Curr. Biol. 9:R602–R605).