In biological tissues, it is now well-understood that mechanical cues are a powerful mechanism for pattern regulation. While much work has focused on interactions between cells and external substrates, recent experiments suggest that cell polarization and motility might be governed by the internal shear stiffness of nearby tissue, deemed “plithotaxis”. Meanwhile, other work has demonstrated that there is a direct relationship between cell shapes and tissue shear modulus in confluent tissues. Joining these two ideas, we develop a hydrodynamic model that couples cell shape, and therefore tissue stiffness, to cell motility and polarization. Using linear stability analysis and numerical simulations, we find that tissue behavior can be tuned between largely homogeneous states and patterned states such as asters, controlled by a composite “morphotaxis” parameter that encapsulates the nature of the coupling between shape and polarization. The control parameter is in principle experimentally accessible, and depends both on whether a cell tends to move in the direction of lower or higher shear modulus, and whether sinks or sources of polarization tend to fluidize the system.

中文翻译：

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运动组织中形状驱动的刚性转变的流体力学†

在生物组织中，众所周知，机械提示是模式调节的强大机制。尽管许多工作集中在细胞与外部基质之间的相互作用上，但最近的实验表明，细胞的极化和运动性可能受附近组织的内部剪切刚度（被称为“多轴性”）的支配。同时，其他工作表明，汇合组织中细胞形状与组织剪切模量之间存在直接关系。结合这两个想法，我们开发了一种流体动力学模型，该模型将细胞形状以及组织刚度与细胞运动性和极化联系在一起。使用线性稳定性分析和数值模拟，我们发现组织行为可以在大致均质状态和构图状态（例如翠菊，由复合“形态轴”参数控制，该参数封装了形状和极化之间耦合的性质。控制参数原则上可以通过实验获得，并且取决于单元是否倾向于在较低或较高的剪切模量方向上移动，以及极化的吸收源或极化源是否倾向于使系统流态化。