论文标题
弯曲的生物组织中形状驱动的汇合刚度过渡
Shape driven confluent rigidity transition in curved biological tissues
论文作者
论文摘要
集体细胞运动是胚胎发育过程中结构形成的基础。组织表现出紧急的多细胞特征,例如干扰,刚度过渡和玻璃动力学,但是关于这些组织尺度如何从局部细胞水平衍生而成的问题仍然存在疑问。具体而言,几乎没有考虑到局部组织几何形状与影响较大的组织行为的相互作用。在这里,我们考虑了汇合组织单层的简单二维计算顶点模型,该模型在球形表面上表现出由细胞的形状指数(外周与平方根区域的比率)控制的刚度相变。我们表明,刚度过渡的临界点是曲率的函数,因此更高度弯曲的系统更有可能处于较不刚性,更多的流体相位。我们为曲率和形状索引生成的相图构成了该模型的可检验预测。曲率依赖性很有趣,因为它暗示了更高表面曲率区域中更动态的组织重塑和便捷生长的自然解释,而无需调用对生化或其他物理差异的需求。这具有潜在的后果,以了解我们对萌芽和分支结构的形态发生。
Collective cell motions underlie structure formation during embryonic development. Tissues exhibit emergent multicellular characteristics such as jamming, rigidity transitions, and glassy dynamics, but there remain questions about how those tissue scale dynamics derive from local cell level properties. Specifically, there has been little consideration of the interplay between local tissue geometry and cellular properties influencing larger scale tissue behaviours. Here we consider a simple two dimensional computational vertex model for confluent tissue monolayers, which exhibits a rigidity phase transition controlled by the shape index (ratio of perimeter to square root area) of cells, on a spherical surface. We show that the critical point for the rigidity transition is a function of curvature such that more highly curved systems are more likely to be in a less rigid, more fluid, phase. A phase diagram we generate for the curvature and shape index constitutes a testable prediction from the model. The curvature dependence is interesting because it suggests a natural explanation for more dynamic tissue remodelling and facile growth in regions of higher surface curvature, without invoking the need for biochemical or other physical differences. This has potential ramifications for our understanding of morphogenesis of budding and branching structures.