Department of Physics, Korea University, Seoul, Korea.
PLoS One. 2011;6(6):e20255. doi: 10.1371/journal.pone.0020255. Epub 2011 Jun 7.
The coordinated motion of a cell is fundamental to many important biological processes such as development, wound healing, and phagocytosis. For eukaryotic cells, such as amoebae or animal cells, the cell motility is based on crawling and involves a complex set of internal biochemical events. A recent study reported very interesting crawling behavior of single cell amoeba: in the absence of an external cue, free amoebae move randomly with a noisy, yet, discernible sequence of 'run-and-turns' analogous to the 'run-and-tumbles' of swimming bacteria. Interestingly, amoeboid trajectories favor zigzag turns. In other words, the cells bias their crawling by making a turn in the opposite direction to a previous turn. This property enhances the long range directional persistence of the moving trajectories. This study proposes that such a zigzag crawling behavior can be a general property of any crawling cells by demonstrating that 1) microglia, which are the immune cells of the brain, and 2) a simple rule-based model cell, which incorporates the actual biochemistry and mechanics behind cell crawling, both exhibit similar type of crawling behavior. Almost all legged animals walk by alternating their feet. Similarly, all crawling cells appear to move forward by alternating the direction of their movement, even though the regularity and degree of zigzag preference vary from one type to the other.
细胞的协调运动是许多重要生物学过程的基础，例如发育、伤口愈合和吞噬作用。对于真核细胞，如变形虫或动物细胞，细胞运动基于爬行，并涉及一系列复杂的内部生化事件。最近的一项研究报告了单细胞变形虫非常有趣的爬行行为：在没有外部提示的情况下，自由变形虫随机移动，具有嘈杂但可识别的“奔跑-转弯”序列，类似于游泳细菌的“奔跑-翻滚”。有趣的是，变形虫轨迹偏向于之字形转弯。换句话说，细胞通过向与前一个转弯相反的方向转弯来改变其爬行方向。这种特性增强了运动轨迹的长程方向持久性。这项研究通过证明以下两点，提出了这种之字形爬行行为可能是任何爬行细胞的普遍特性：1）小神经胶质细胞，即大脑的免疫细胞，以及 2）一个简单的基于规则的模型细胞，它包含了细胞爬行背后的实际生物化学和力学，这两者都表现出类似类型的爬行行为。几乎所有有腿的动物都是通过交替脚来行走。同样，所有爬行细胞似乎都是通过交替运动方向来向前移动，尽管其之字形偏好的规律性和程度因类型而异。
