The dispersal of cells from an initially constrained location is a crucial aspect of many physiological phenomena, ranging from morphogenesis to tumour spreading. In such processes, cell–cell interactions may deeply alter the motion of single cells, and in turn the collective dynamics. While contact phenomena like contact inhibition of locomotion are known to come into play at high densities, here we focus on the little explored case of non-cohesive cells at moderate densities. We fully characterize the spreading of micropatterned colonies of Dictyostelium discoideum cells from the complete set of individual trajectories. From data analysis and simulation of an elementary model, we demonstrate that contact interactions act to speed up the early population spreading by promoting individual cells to a state of higher persistence, which constitutes an as-yet unreported contact enhancement of locomotion. Our findings also suggest that the current modelling paradigm of memoryless active particles may need to be extended to account for the history-dependent internal state of motile cells.

中文翻译：

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传播细胞集落中运动的接触增强

从最初受约束的位置散布细胞是许多生理现象（从形态发生到肿瘤扩散）的关键方面。在这样的过程中，细胞间的相互作用可能会深刻改变单个细胞的运动，进而改变集体动力。虽然众所周知，在高密度下会发生接触现象，例如运动的接触抑制，但在此我们关注的是在中等密度下很少探索的非粘性细胞的情况。我们充分表征了盘基网柄菌的微模式菌落的扩散完整的单个轨迹集合中的单元。从基本模型的数据分析和模拟中，我们证明了接触相互作用通过促进单个细胞达到更高的持久性状态来加速早期种群的传播，这构成了迄今尚未报道的运动性接触增强。我们的发现还表明，无记忆活性颗粒的当前建模范例可能需要扩展，以解决运动细胞历史依赖的内部状态的问题。