近日，香港中文大学的Yilin Wu及其研究团队取得一项新进展。经过不懈努力，他们发现自增强的移动性使生物物质形成涡旋模式。相关研究成果已于2024年3月13日在国际权威学术期刊《自然》上发表。

该研究团队发现了一种全新的自组织模式形成途径，这一途径由物理相互作用驱动，能够创造出具有多尺度有序的大尺度规则空间结构。具体而言，研究人员观察到密集的细菌生命物质能够自发地形成中尺度的、快速旋转的涡旋晶格。每个涡旋由大约10⁴至10⁵个可运动的细菌细胞组成，这些细胞在大于厘米的尺度上按照明显的六边形序排列。而涡旋中的单个细胞则以强极性和涡旋序在协调方向上移动。

通过单细胞跟踪和数值模拟，研究人员发现这一现象是由系统中自我增强的移动性实现的。也就是说，在特定的细胞密度下，单个细胞的速度会随着细胞产生的集体应力而增加。这种应力诱导的移动增强和流化在致密生物物质的不同长度尺度中普遍存在。这项研究结果表明，自增强的移动性为生命系统的模式形成提供了一种简单的物理机制，同时也在更广泛的范围内，如类流体和类固体行为边界附近的其他活性物质系统中发挥作用。

据悉，从亚细胞细胞器生物发生到胚胎发育，自组织结构的形成是生命系统的一个标志。生物学中有序空间模式的出现通常是由协调细胞行为和分化的复杂化学信号驱动的，而纯粹的物理相互作用可以驱动规则生物模式的形成，例如精子和细菌悬浮液中的结晶涡旋阵列。

附：英文原文

Title: Self-enhanced mobility enables vortex pattern formation in living matter

Author: Xu, Haoran, Wu, Yilin

Issue&Volume: 2024-03-13

Abstract: Ranging from subcellular organelle biogenesis to embryo development, the formation of self-organized structures is a hallmark of living systems. Whereas the emergence of ordered spatial patterns in biology is often driven by intricate chemical signalling that coordinates cellular behaviour and differentiation, purely physical interactions can drive the formation of regular biological patterns such as crystalline vortex arrays in suspensions of spermatozoa and bacteria. Here we discovered a new route to self-organized pattern formation driven by physical interactions, which creates large-scale regular spatial structures with multiscale ordering. Specifically we found that dense bacterial living matter spontaneously developed a lattice of mesoscale, fast-spinning vortices; these vortices each consisted of around 10⁴–10⁵motile bacterial cells and were arranged in space at greater than centimetre scale and with apparent hexagonal order, whereas individual cells in the vortices moved in coordinated directions with strong polar and vortical order. Single-cell tracking and numerical simulations suggest that the phenomenon is enabled by self-enhanced mobility in the system—that is, the speed of individual cells increasing with cell-generated collective stresses at a given cell density. Stress-induced mobility enhancement and fluidization is prevalent in dense living matter at various scales of length. Our findings demonstrate that self-enhanced mobility offers a simple physical mechanism for pattern formation in living systems and, more generally, in other active matter systems near the boundary of fluid- and solid-like behaviours.

DOI: 10.1038/s41586-024-07114-8

Source: https://www.nature.com/articles/s41586-024-07114-8