Fuss Bernhard, Josten Frank, Feix Maritta, Hoch Michael
Universität Bonn, Institut für Molekulare Physiologie und Entwicklungsbiologie, Abteilung für Molekulare Entwicklungsbiologie, Poppelsdorfer Schloss, D-53115 Bonn, Germany.
Development. 2004 Apr;131(7):1587-95. doi: 10.1242/dev.01057. Epub 2004 Mar 3.
Notch signalling is an evolutionarily conserved cell interaction mechanism, the role of which in controlling cell fate choices has been studied extensively. Recent studies in both vertebrates and invertebrates revealed additional functions of Notch in proliferation and apoptotic events. We provide evidence for an essential role of the Notch signalling pathway during morphogenetic cell movements required for the formation of the foregut-associated proventriculus organ in the Drosophila embryo. We demonstrate that the activation of the Notch receptor occurs in two rows of boundary cells in the proventriculus primordium. The boundary cells delimit a population of foregut epithelial cells that invaginate into the endodermal midgut layer during proventriculus morphogenesis. Notch receptor activation requires the expression of its ligand Delta in the invaginating cells and apical Notch receptor localisation in the boundary cells. We further show that the movement of the proventricular cells is dependent on the short stop gene that encodes the Drosophila plectin homolog of vertebrates and is a cytoskeletal linker protein of the spectraplakin superfamily. short stop is transcriptionally activated in response to the Notch signalling pathway in boundary cells and we demonstrate that the localisation of the Notch receptor and Notch signalling activity depend on short stop activity. Our results provide a novel link between the Notch signalling pathway and cytoskeletal reorganisation controlling cell movement during the development of foregut-associated organs.
Notch信号通路是一种在进化上保守的细胞相互作用机制，其在控制细胞命运选择中的作用已得到广泛研究。最近在脊椎动物和无脊椎动物中的研究揭示了Notch在增殖和凋亡事件中的其他功能。我们提供证据表明，Notch信号通路在果蝇胚胎中前肠相关嗉囊器官形成所需的形态发生细胞运动过程中起着至关重要的作用。我们证明，Notch受体的激活发生在嗉囊原基的两排边界细胞中。边界细胞界定了一群前肠上皮细胞，这些细胞在嗉囊形态发生过程中向内凹陷进入内胚层中肠层。Notch受体的激活需要其配体Delta在凹陷细胞中的表达以及边界细胞中顶端Notch受体的定位。我们进一步表明，嗉囊细胞的运动依赖于短停基因，该基因编码脊椎动物的果蝇网蛋白同源物，是光谱斑蛋白超家族的一种细胞骨架连接蛋白。短停基因在边界细胞中响应Notch信号通路而被转录激活，并且我们证明Notch受体的定位和Notch信号活性依赖于短停基因的活性。我们的结果在Notch信号通路与细胞骨架重组之间建立了一种新的联系，这种重组在与前肠相关器官的发育过程中控制细胞运动。
