Futrelle R P
J Cell Biochem. 1982;18(2):197-212. doi: 10.1002/jcb.1982.240180207.
Four aspects of ameboid cell chemotaxis are discussed: 1) Ameboid cells (Dictyostelium discoideum, leukocytes) might orient to chemotaxin gradients by sensing a spatial gradient or a temporal change in the concentration. Using a moving micropipette source of cAMP, we show the D discoideum cells can orient toward the gradient in which the concentration is everywhere decreasing with time-implying a spatial mechanism. 2) The number of molecules N that must be released by a source to orient a cell is limited by the natural concentration "noise" due to diffusion. N is shown to be simply related to the cell size and the distance from the source. 3) We show that previous diffusion equations for cell population movement have not taken the speed variations (klinokinesis) into account properly, and we present a new result that does. 4) We briefly discuss reaction-diffusion models of cell orientation.
1）阿米巴样细胞（盘基网柄菌、白细胞）可能通过感知浓度的空间梯度或时间变化来定向于趋化因子梯度。使用移动的cAMP微量移液器源，我们表明盘基网柄菌细胞可以朝着浓度随时间处处降低的梯度定向，这意味着一种空间机制。2）源为使细胞定向而必须释放的分子数N受到扩散引起的自然浓度“噪声”的限制。N被证明与细胞大小和距源的距离简单相关。3）我们表明，先前用于细胞群体运动的扩散方程没有正确考虑速度变化（调转趋性），我们给出了一个考虑了该因素的新结果。4）我们简要讨论了细胞定向的反应扩散模型。
