The path of moving eukaryotic cells depends on the kinetics and direction of extending pseudopods. Amoeboid cells constantly change their shape with pseudopods extending in different directions. Detailed analysis has revealed that time, place and direction of pseudopod extension are not random, but highly ordered with strong prevalence for only one extending pseudopod, with defined life-times, and with reoccurring events in time and space indicative of memory. Important components are Ras activation and the formation of branched F-actin in the extending pseudopod and inhibition of pseudopod formation in the contractile cortex of parallel F-actin/myosin. In biology, order very often comes with symmetry. In this essay, I discuss cell movement and the dynamics of pseudopod extension from the perspective of symmetry and symmetry changes of Ras activation and the formation of branched F-actin in the extending pseudopod. Combining symmetry of Ras activation with kinetics and memory of pseudopod extension results in a refined model of amoeboid movement that appears to be largely conserved in the fast moving Dictyostelium and neutrophils, the slow moving mesenchymal stem cells and the fungus B.d. chytrid.

中文翻译：

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在兴奋性，动力学微调和伪足形成记忆的背景下，细胞运动过程中的对称性破坏。

移动的真核细胞的路径取决于延伸的假足的动力学和方向。变形虫细胞不断变化形状，伪足向不同方向延伸。详细的分析显示伪足扩展的时间，位置和方向不是随机的，而是高度有序的，仅对于一个扩展的伪足具有很强的流行性，具有定义的生存时间，并且在时间和空间上会发生反复发生的事件以指示内存。重要的成分是Ras活化和延伸的假足中分支F-肌动蛋白的形成，以及平行F-肌动蛋白/肌球蛋白的收缩皮层中假足形成的抑制。在生物学中，秩序常常是对称的。在这篇文章中 我从Ras激活的对称性和对称性变化以及延伸假足中支链F-肌动蛋白的形成的对称性和角度讨论细胞运动和假足延伸的动力学。Ras激活的对称性与动力学和假足延伸的记忆相结合，形成了一个精确的变形虫运动模型，该模型在快速运动中似乎基本上是保守的Dictyostelium和中性粒细胞，缓慢移动的间充质干细胞和真菌Bd chytrid。