Hadjifrangiskou Ioannis, Ruske Liam J, Yeomans Julia M
The Rudolf Peierls Centre for Theoretical Physics, Beecroft Building, Parks Road, Oxford, OX1 3PU, UK.
Soft Matter. 2023 Sep 13;19(35):6664-6670. doi: 10.1039/d3sm00627a.
The hydrodynamic theory of active nematics has been often used to describe the spatio-temporal dynamics of cell flows and motile topological defects within soft confluent tissues. Those theories, however, often rely on the assumption that tissues consist of cells with a fixed, anisotropic shape and do not resolve dynamical cell shape changes due to flow gradients. In this paper we extend the continuum theory of active nematics to include cell shape deformability. We find that circular cells in tissues must generate sufficient active stress to overcome an elastic barrier to deforming their shape in order to drive tissue-scale flows. Above this threshold the systems enter a dynamical steady-state with regions of elongated cells and strong flows coexisting with quiescent regions of isotropic cells.
活性向列相的流体动力学理论常被用于描述软汇合组织内细胞流动和动态拓扑缺陷的时空动力学。然而，这些理论通常依赖于这样的假设：组织由具有固定各向异性形状的细胞组成，并且无法解决由于流动梯度导致的细胞形状动态变化。在本文中，我们扩展了活性向列相的连续介质理论，以纳入细胞形状的可变形性。我们发现，组织中的圆形细胞必须产生足够的活性应力，以克服使其形状变形的弹性障碍，从而驱动组织尺度的流动。超过这个阈值后，系统进入动态稳态，其中伸长细胞区域和强流与各向同性细胞的静止区域共存。
