Varnum B, Edwards K B, Soll D R
J Cell Biol. 1985 Jul;101(1):1-5. doi: 10.1083/jcb.101.1.1.
Using a perfusion chamber, we examined the behavior of individual amebae in increasing and decreasing temporal gradients of cAMP. We demonstrated that amebae respond to increasing temporal gradients of cAMP with stimulated motility and to corresponding decreasing temporal gradients with depressed motility. Depressed motility observed in decreasing temporal gradients corresponded to the inhibited levels observed when cAMP was applied at constant concentrations. These results were consistent with a simple model for the motile behavior of amebae in an early aggregation territory in which nondissipating waves of cAMP originate at the aggregation center and travel outward periodically. We conclude that chemotactically responsive amebae can assess whether a temporal gradient of chemoattractant is increasing or decreasing in the absence of a spatial gradient, and can adjust their motility accordingly.
我们使用灌注室，研究了单个变形虫在cAMP时间梯度增加和减少时的行为。我们证明，变形虫对cAMP时间梯度增加的反应是运动性增强，对相应的时间梯度减少的反应是运动性降低。在时间梯度降低时观察到的运动性降低与在恒定浓度下施加cAMP时观察到的抑制水平相对应。这些结果与一个简单的模型一致，该模型描述了早期聚集区域中变形虫的运动行为，即cAMP的非耗散波在聚集中心产生并周期性地向外传播。我们得出结论，具有趋化反应的变形虫在没有空间梯度的情况下，可以评估趋化因子的时间梯度是在增加还是在减少，并相应地调整其运动性。
