单细胞生物螺旋虫能在毫秒级时间内极速收缩

由北卡罗来纳州立大学、芝加哥大学、德雷克大学和科罗拉多大学博尔德分校等机构组成的研究团队发现，单细胞生物螺旋虫具有超常的身体收缩能力。1该生物能在5毫秒内将身体压缩至原长的四分之一，收缩速度达到每秒100个身体长度，比人类眨眼的速度快数百倍。1相比之下，人类肌肉完成相同比例的收缩需要约10倍的时间。1

研究人员揭示了这一非凡收缩机制的分子基础。1螺旋虫的收缩由钙离子和由centrin与Sfi1蛋白组成的鱼网状肌动蛋白网络共同驱动。1当钙离子存在时，Sfi1蛋白会失去硬度并团聚成湿面团的质地，从而使这个蛋白网络紧缩。1这种机制与人类肌肉本质上不同——螺旋虫依靠钙离子提供动力，而非ATP供能。1这一研究成果已发表在《美国国家科学院院刊》2026年第123卷第22期上，为开发更快的人工肌肉提供了潜在的设计灵感。1

Researchers have identified the mechanism behind an extraordinary feat of biological engineering: the single-celled organism Spirostomum can compress its body to one quarter of its original length in just 5 milliseconds 1. This contraction speed, equivalent to roughly 100 body lengths per second, far outpaces human muscle capacity—human muscles would require approximately 10 times longer to achieve a similar proportional contraction 1.

The rapid shrinking is driven by a distinctive mechanism involving calcium ions and a net-like network of proteins composed of centrin and Sfi1 1. When calcium ions are present, Sfi1 proteins lose their rigidity and aggregate into a wet dough-like consistency, causing the actin network to tighten and trigger the contraction 1. This calcium-driven system fundamentally differs from human muscles, which rely on adenosine triphosphate (ATP) as their energy source 1. The findings, published in the Proceedings of the National Academy of Sciences in 2026 (volume 123, issue 22), emerged from collaborative work involving researchers at North Carolina State University, the University of Chicago, Drake University, and the University of Colorado Boulder 1. The discovery could inspire the development of faster artificial muscles for technological applications 1.