The Gurdon Institute and the Department of Genetics, University of Cambridge, Tennis Court Rd, Cambridge CB2 1QN, United Kingdom.
Curr Opin Cell Biol. 2011 Oct;23(5):540-6. doi: 10.1016/j.ceb.2011.07.005. Epub 2011 Jul 30.
The adult form of a multicellular organism is shaped by a series of morphogenetic processes that organise the body into tissues and organs. Most of these events involve the deformation of sheets of epithelial cells that are highly polarised along their apical-basal axes and attached to each other by lateral junctions. Here we discuss the role played by modifications in the apical-basal polarity system in driving morphogenesis, with an emphasis on well-characterised events during Drosophila development. Changing the activity of polarity factors can alter the relative sizes of the apical, lateral and basal domains. This can drive transitions between cuboidal, columnar and squamous epithelial morphologies, to increase or decrease the surface area of an epithelial sheet. These changes can also cause epithelial cells to become wedge-shaped, which can drive tissue bending and invagination. In addition, it has recently emerged that the activity of apical-basal polarity factors can also be modulated in a planar polarised manner. By affecting the contractility of the actomyosin cytoskeleton and the stability of adherens junctions, changes within the plane of the epithelium can cause cell rearrangements that contribute to convergence and extension movements, boundary formation and cell alignment.
多细胞生物的成体形态是由一系列形态发生过程塑造的，这些过程将身体组织和器官组织成不同的结构。这些事件中的大多数都涉及到上皮细胞片的变形，这些细胞沿着它们的顶端-基底轴高度极化，并通过侧向连接彼此附着。在这里，我们讨论了顶端-基底极性系统的改变在驱动形态发生中的作用，重点介绍了在果蝇发育过程中特征明确的事件。改变极性因子的活性可以改变顶端、侧向和基底域的相对大小。这可以驱动立方、柱状和鳞状上皮形态之间的转变，从而增加或减少上皮片的表面积。这些变化还可以使上皮细胞变成楔形，从而可以驱动组织弯曲和内陷。此外，最近出现的情况是，顶端-基底极性因子的活性也可以以平面极化的方式进行调节。通过影响肌动球蛋白细胞骨架的收缩性和黏着连接的稳定性，上皮细胞平面内的变化可以引起细胞重排，从而有助于汇聚和延伸运动、边界形成和细胞对齐。
