Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, UK.
Nat Commun. 2023 Dec 20;14(1):8475. doi: 10.1038/s41467-023-43973-x.
Vertebrate neural tube closure is associated with complex changes in cell shape and behavior, however, the relative contribution of these processes to tissue folding is not well understood. At the onset of Xenopus neural tube folding, we observed alternation of apically constricted and apically expanded cells. This apical domain heterogeneity was accompanied by biased cell orientation along the anteroposterior axis, especially at neural plate hinges, and required planar cell polarity signaling. Vertex models suggested that dispersed isotropically constricting cells can cause the elongation of adjacent cells. Consistently, in ectoderm, cell-autonomous apical constriction was accompanied by neighbor expansion. Thus, a subset of isotropically constricting cells may initiate neural plate bending, whereas a 'tug-of-war' contest between the force-generating and responding cells reduces its shrinking along the body axis. This mechanism is an alternative to anisotropic shrinking of cell junctions that are perpendicular to the body axis. We propose that apical domain changes reflect planar polarity-dependent mechanical forces operating during neural folding.
脊椎动物神经管的闭合与细胞形状和行为的复杂变化有关，然而，这些过程对组织折叠的相对贡献尚不清楚。在非洲爪蟾神经管开始折叠时，我们观察到细胞顶端的收缩和扩张交替发生。这种顶端域的异质性伴随着沿着前后轴的细胞取向的偏倚，尤其是在神经板铰链处，并且需要平面细胞极性信号。顶点模型表明，分散的各向同性收缩细胞可以导致相邻细胞的伸长。一致地，在外胚层中，细胞自主的顶端收缩伴随着相邻细胞的扩张。因此，一小部分各向同性收缩的细胞可能会引发神经管弯曲，而产生力的细胞和响应细胞之间的“拔河”竞赛会减少其沿着体轴的收缩。这种机制是一种替代垂直于体轴的细胞连接的各向异性收缩的机制。我们提出，顶端域的变化反映了在神经折叠过程中平面极性依赖性机械力的作用。
