Hava David, Forster Ulrike, Matsuda Miho, Cui Shuang, Link Brian A, Eichhorst Jenny, Wiesner Burkhard, Chitnis Ajay, Abdelilah-Seyfried Salim
Max Delbrück Center (MDC) for Molecular Medicine, D-13125 Berlin, Germany.
J Cell Sci. 2009 Mar 1;122(Pt 5):687-95. doi: 10.1242/jcs.032102. Epub 2009 Feb 10.
Tissue morphogenesis and cell sorting are major forces during organ development. Here, we characterize the process of tissue morphogenesis within the zebrafish lateral line primordium, a migratory sheet of cells that gives rise to the neuromasts of the posterior lateral line organ. We find that cells within this epithelial tissue constrict actin-rich membranes and enrich apical junction proteins at apical focal points. The coordinated apical membrane constriction in single Delta D-positive hair cell progenitors and in their neighbouring prospective support cells generates cellular rosettes. Live imaging reveals that cellular rosettes subsequently separate from each other and give rise to individual neuromasts. Genetic analysis uncovers an involvement of Lethal giant larvae proteins in the maturation of apical junction belts during cellular rosette formation. Our findings suggest that apical constriction of cell membranes spatially confines regions of strong cell-cell adhesion and restricts the number of tightly interconnected cells into cellular rosettes, which ensures the correct deposition of neuromasts during morphogenesis of the posterior lateral line organ.
组织形态发生和细胞分选是器官发育过程中的主要力量。在这里，我们描述了斑马鱼侧线原基内的组织形态发生过程，侧线原基是一层迁移的细胞，可形成后侧线器官的神经丘。我们发现，这种上皮组织中的细胞会收缩富含肌动蛋白的膜，并在顶端焦点处富集顶端连接蛋白。单个Delta D阳性毛细胞祖细胞及其相邻的潜在支持细胞中协调的顶端膜收缩产生了细胞玫瑰花结。实时成像显示，细胞玫瑰花结随后彼此分离并形成单个神经丘。遗传分析揭示了致死性巨幼虫蛋白在细胞玫瑰花结形成过程中顶端连接带成熟中的作用。我们的研究结果表明，细胞膜的顶端收缩在空间上限制了强细胞间粘附的区域，并将紧密相连的细胞数量限制在细胞玫瑰花结中，这确保了后侧线器官形态发生过程中神经丘的正确沉积。
