Cellular memory in eukaryotic chemotaxis depends on the background chemoattractant concentration
Cellular memory in eukaryotic chemotaxis depends on the background chemoattractant concentration
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真核趋化中的细胞记忆取决于背景趋化剂浓度
DOI：
10.1103/physreve.103.012402
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发表时间：
2021
影响因子：
2.4
通讯作者：
Rappel, Wouter-Jan
中科院分区：
文献类型：
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作者：
Karmakar, Richa;Tang, Man-Ho;Yue, Haicen;Lombardo, Daniel;Karanam, Aravind;Camley, Brian A.;Groisman, Alex;Rappel, Wouter-Jan
作为自组织聚集过程的一部分，社会变形虫的细胞迁移到化学吸引剂的周期性行波来源。这一过程的一个重要部分是细胞记忆，它使细胞能够对波的前端做出反应，而忽略波后的向下梯度。在这种聚集过程中，化学诱导剂的本底浓度逐渐上升。在我们的微流体实验中，我们外源地应用了具有不同背景水平的化学诱导剂的周期波。我们发现，增加背景并不会使波的检测变得更加困难，这将是天真的预期。相反，我们看到化学趋化效率在背景浓度的中间值时显著增加，但在背景浓度较大时以类似开关的方式降低到几乎为零。这些结果与包含双稳态存储模块和非自适应组件的计算模型是一致的。在这个模型中，中等背景水平通过保持记忆激活来帮助保持定向迁移，但当背景水平较高时，来自波的定向刺激不再足以激活双稳态记忆，从而抑制定向迁移。这些结果表明，提高趋化剂背景水平可能促进网柄菌落的自组织聚集。
Cells of the social amoebaDictyostelium discoideummigrate to a source of periodic traveling waves of chemoattractant as part of a self-organized aggregation process. An important part of this process is cellular memory, which enables cells to respond to the front of the wave and ignore the downward gradient in the back of the wave. During this aggregation, the background concentration of the chemoattractant gradually rises. In our microfluidic experiments, we exogenously applied periodic waves of chemoattractant with various background levels. We find that increasing background does not make detection of the wave more difficult, as would be naively expected. Instead, we see that the chemotactic efficiency significantly increases for intermediate values of the background concentration but decreases to almost zero for large values in a switch-like manner. These results are consistent with a computational model that contains a bistable memory module, along with a nonadaptive component. Within this model, an intermediate background level helps preserve directed migration by keeping the memory activated, but when the background level is higher, the directional stimulus from the wave is no longer sufficient to activate the bistable memory, suppressing directed migration. These results suggest that raising levels of chemoattractant background may facilitate the self-organized aggregation inDictyosteliumcolonies.