Dynamic actin-based epithelial adhesion and cell matching during Drosophila dorsal closure

摘要: Abstract Background: The adhesion of two epithelial sheets is a fundamental process that occurs throughout embryogenesis and during wound repair. Sealing the dorsal epidermis along midline Drosophila embryo provides genetically tractable model to analyse closure such holes. Several studies indicate actin cytoskeleton plays critical role in closure. Although many components signalling cascade directing this have been identified, precise cell-biological events upon which these signals act remain poorly described. Results: By confocal imaging living fly embryos expressing green fluorescent protein (GFP)-tagged actin, we found relies on activity dynamic filopodia lamellipodia extend from front-row cells actively zipper together. As fronts approach one another, observed long, thin filopodia, apparently ‘sampling' opposing face. When assembly actin-based protrusions was blocked (by interfering with activities Cdc42 Jun N-terminal kinase signalling), fusion prevented their ability ‘sense' correct partners also blocked, leading segment misalignment seam. Conclusions: Dynamic, (filopodia lamellae) are critical, both mechanics ‘matching'