Inversely correlated cycles in speed and turning in an Ameba: An oscillatory model of cell locomotion
Inversely correlated cycles in speed and turning in an Ameba: An oscillatory model of cell locomotion
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DOI：
10.1016/s0006-3495(97)78883-0
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发表时间：
1997-05-01
影响因子：
3.4
通讯作者：
Sheetz, MP
中科院分区：
文献类型：
--
作者：
Shenderov, AD;Sheetz, MP
以前的变形虫爬行的生物物理模型描述了细胞的运动在一个持续的随机行走。在后一种模型中，速度和方向被视为独立的、时间均匀的随机过程。我们在这里表明，至少在盘状盘基骨柱的情况下，速度控制和重新定向过程都涉及确定性的周期性成分。我们还表明，这些过程是同步的，负相关的，正如早期的发现所表明的那样。也就是说，增加的转弯与缓慢移动的时间相关。因此，以前的模型与细胞的行为不一致。使用启发式方法，我们开发了一个数学模型，描述了细胞的速度和质心运动的统计特性。我们的观察结果和模型与变形虫运动的现象学描述是一致的，变形虫运动是假足伸展和收缩的循环过程。
Previous biophysical models of ameboid crawling have described cell movement in terms of a persistent random walk. Speed and orientation were treated in the latter model as independent and temporally homogeneous stochastic processes. We show here that, at least in the case of Dictyostelium discoideum, both speed control and reorientation processes involve a deterministic, periodic component. We also show that the processes are synchronized and negatively correlated, as was suggested by earlier findings. That is, increased turning correlates with periods of slow movement. Therefore, previous models are inconsistent with the behaivor of cells. Using a heuristic approach, we have developed a mathematical model that describes the statistical properties of the cell's velocity and movement of its centroid. Our observations and the model are consistent with the phenomenological description of ameboid motility as a cyclic process of pseudopod extension and retraction.