Physical limits on cellular sensing of spatial gradients.
Physical limits on cellular sensing of spatial gradients.
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DOI：
10.1103/physrevlett.105.048104
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发表时间：
2010-07-23
影响因子：
8.6
通讯作者：
Levine H
中科院分区：
文献类型：
--
作者：
Hu B;Chen W;Rappel WJ;Levine H
许多真核细胞能够通过直接测量空间浓度差异来感知化学梯度。这种梯度传感的精度受到扩散颗粒与细胞表面特定受体结合的波动的限制。在这里，我们通过将趋化细胞建模为受空间变化场影响的Ising自旋链来探索空间感知机制的物理极限。这使我们能够推导出梯度参数的极大似然估计量以及它们的渐近不确定性的显式表达式。准确度随着细胞的大小而增加，我们的结果表明，通过引入相邻受体之间的非零协同性，这种准确度进一步提高。因此，与最近的实验数据一致，小细菌有可能进行梯度的空间测量。
Many eukaryotic cells are able to sense chemical gradients by directly measuring spatial concentration differences. The precision of such gradient sensing is limited by fluctuations in the binding of diffusing particles to specific receptors on the cell surface. Here, we explore the physical limits of the spatial sensing mechanism by modeling the chemotactic cell as an Ising spin chain subject to a spatially varying field. This allows us to derive the maximum likelihood estimators of the gradient parameters as well as explicit expressions for their asymptotic uncertainties. The accuracy increases with the cell’s size and our results demonstrate that this accuracy be further increased by introducing a non-zero cooperativity between neighboring receptors. Thus, consistent with recent experimental data, it is possible for small bacteria to perform spatial measurements of gradients.