发表机构
Weizmann Institute of Science（魏茨曼科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出运动单元模型，用离散自旋模拟细胞极化与运动，通过极性线索产生自推进，展现三种动力学相，并整合外部线索，为细胞迁移提供新框架。
AI 中文摘要
我们提出了一种用于二维细胞运动的粗粒化相互作用自旋模型，其中细胞周长被离散化为随机二值自旋，这些自旋在活跃和非活跃状态之间切换。每个周长自旋代表一个“运动单元”，当其活跃时，是突出力（protrusive force）和逆流（retrograde flow）的来源。运动单元之间的长程相互作用通过由集体肌动蛋白逆流平流输送的极性线索（polarity cue）产生，从而提供了自发对称性破缺和自推进的最小实现。该模型表现出三种动力学相：随机游走相、持续随机游走相，以及以跑停（run-and-tumble）迁移为特征的间歇性双稳态相。额外的最近邻相互作用调节速度和持续性，而不改变整体相结构。由于其简单性，该框架自然地整合了外部线索，再现了趋化迁移、通过局部光遗传学激活的转向，以及在竞争刺激下的方向决策（对称性破缺）。该模型引入了一类新的活性粒子模型，其中速度和极性均从内部随机自旋动力学中涌现，而非作为粒子级变量被强加，为细胞迁移研究提供了框架，并扩展了活性物质物理学的范围。
英文摘要
We introduce a coarse-grained interacting-spin model for two-dimensional cell motility, in which the cell perimeter is discretized into stochastic binary spins that switch between active and inactive states. Each perimeter spin represents a "motile-unit" that is a source of protrusive force and retrograde flow when active. Long-range interactions between the motile-units arise through a polarity cue advected by the collective actin retrograde flow, providing a minimal realization of spontaneous symmetry breaking and self-propulsion. The model exhibits three dynamical phases, a random walk phase, persistent random walk phase, and an intermittent bistable phase characterized by run-and-tumble migration. Additional nearest-neighbor interactions modulate speed and persistence without altering the overall phase structure. Owing to its simplicity, the framework naturally incorporates external cues, reproducing chemotactic migration, steering by localized optogenetic activation, and directional decision-making (symmetry breaking) under competing stimuli. The model introduces a new class of active-particle model in which both speed and polarity emerge from internal stochastic spin dynamics, rather than being imposed as particle-level variables, offering a framework for the study of cell migration and extends the scope of active-matter physics.
