Dynamic actin-based epithelial adhesion and cell matching during Drosophila dorsal closure
Dynamic actin-based epithelial adhesion and cell matching during Drosophila dorsal closure
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DOI：
10.1016/s0960-9822(00)00796-x
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发表时间：
2000-11-16
期刊：
影响因子：
9.2
通讯作者：
Martin, P
中科院分区：
文献类型：
--
作者：
Jacinto, A;Wood, W;Martin, P
背景：两层上皮片之间的粘连是胚胎发生和伤口修复过程中的一个基本过程。果蝇胚胎中线背部表皮的封闭为分析这种孔洞的闭合提供了一个遗传上易于处理的模型。一些研究表明，肌动蛋白细胞骨架在背部闭合中起着关键作用。结果：通过对表达绿色荧光蛋白(GFP)标记的肌动蛋白的活体果蝇胚胎的共聚焦成像，我们发现背部闭合依赖于从前排细胞延伸到主动拉链上皮片的动态丝足和片脂的活动。当这些上皮前额彼此靠近时，我们观察到细长的丝状足细胞，显然是对对面的细胞进行了采样。当这些基于肌动蛋白的突起的组装被阻止时(通过干扰CDC42和Jun N-末端激酶信号的活性)，相对的上皮细胞的黏附和融合被阻止，它们‘感觉’正确伙伴的能力也被阻止，导致沿中线缝隙的节段错位。结论：动态的基于肌动蛋白的突起(丝足和片层)在背部闭合过程中的上皮黏附机制和沿融合缝的相对细胞的正确‘匹配’中都是关键的。
Background: The adhesion of two epithelial sheets is a fundamental process that occurs throughout embryogenesis and during wound repair. Sealing of the dorsal epidermis along the midline of the Drosophila embryo provides a genetically tractable model to analyse the closure of such holes. Several studies indicate that the actin cytoskeleton plays a critical role in dorsal closure. Although many components of the signalling cascade directing this process have been identified, the precise cell-biological events upon which these signals act remain poorly described.Results: By confocal imaging of living fly embryos expressing green fluorescent protein (GFP)-tagged actin, we found that dorsal closure relies on the activity of dynamic filopodia and lamellipodia that extend from front-row cells to actively zipper the epithelial sheets together. As these epithelial fronts approach one another, we observed long, thin filopodia, apparently 'sampling' cells on the opposing face. When the assembly of these actin-based protrusions was blocked (by interfering with the activities of Cdc42 and Jun N-terminal kinase signalling), the adhesion and fusion of opposing epithelial cells was prevented and their ability to 'sense' correct partners was also blocked, leading to segment misalignment along the midline seam.Conclusions: Dynamic, actin-based protrusions (filopodia and lamellae) are critical, both in the mechanics of epithelial adhesion during dorsal closure and in the correct 'matching' of opposing cells along the fusion seam.