How geometry and internal bias affect the accuracy of eukaryotic gradient sensing.
How geometry and internal bias affect the accuracy of eukaryotic gradient sensing.
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DOI：
10.1103/physreve.83.021917
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发表时间：
2011-02
期刊：
影响因子：
--
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
许多运动真核细胞通过配体与膜结合受体的结合测量外部化学梯度来确定其方向。该过程受到结合过程和配体分子扩散引起的波动的限制。在这里，我们应用估计理论方法来确定非圆形单元和具有内部偏差的单元的梯度传感的物理极限。具体来说，我们推导了椭圆细胞中梯度传感精度的理论表达式。高椭圆形细胞的精度可能显着偏离圆形细胞的梯度传感限制。此外，我们发现细胞不能通过拉长细胞体同时提高其对梯度陡度和方向的感知。最后，我们得出了具有内部偏差的细胞梯度传感精度的下限，并将我们的分析结果与最近的实验结果进行了比较。
Many motile eukaryotic cells determine their direction by measuring external chemical gradients through the binding of ligands to membrane bound receptors. This process is limited by fluctuations arising from the binding process and from the diffusion of the ligand molecules. Here, we apply estimation-theoretic methods to determine the physical limits of gradient sensing for cells that are non-circular and for cells that have an internal bias. Specifically, we derive theoretical expressions for the accuracy of gradient sensing in elliptical cells. This accuracy for highly elliptical cells can significantly deviate from the gradient sensing limits derived for circular cells. Furthermore, we find that a cell cannot improve its sensing of the gradient steepness and direction simultaneously by elongating its cell body. Finally, we derive a lower bound on the accuracy of gradient sensing for cells that possess an internal bias and compare our analytical results with recent experimental findings.