论文标题
浓度测量和细胞系统中梯度辨别时间的限制
Limitations on concentration measurements and gradient discerning times in cellular systems
论文作者
论文摘要
这项工作报告了两个结果。首先，我们通过考虑细胞开始测量与趋化因子接触的时刻时，通过考虑现实情况来重新访问Berg和Purcell计算，该计算与细胞浓度测量的误差相关，而不是在经典Berg和Purcell Paper中与趋化浓度平衡后进行测量。我们发现，浓度测量的误差仍然与Berg和Purcell评估的误差相同。接下来，我们在测量时间下得出一个下限，而细胞不可能通过空间感应机制辨别细胞外趋化梯度。该结合独立于扩散速率和趋化图的浓度，而是由从细胞受体的配体脱离速率设置的。结果可以帮助解释实验观察。
This work reports on two results. At first we revisit the Berg and Purcell calculation that provides a lower bound to the error in concentration measurement by cells, by considering the realistic case when the cell starts measuring the moment it comes in contact with the chemoattractants, instead of measuring after equilibrating with the chemotactic concentration as done in the classic Berg and Purcell paper. We find that the error in concentration measurement is still the same as evaluated by Berg and Purcell. We next derive a lower bound on measurement time below which it is not possible for the cell to discern extra-cellular chemotactic gradients through spatial sensing mechanisms. This bound is independent of diffusion rate and concentration of the chemoattracts and is instead set by detachment rate of ligands from the cell receptors. The result could help explain experimental observations.
