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Cells can measure chemical concentrations with extraordinary precision. This raises the question what is the fundamental limit to the accuracy of chemical concentration measurements. In this talk, I will show that the sensing accuracy of passive signaling systems is limited by the number of receptors; a downstream processing network can never increase the sensing precision beyond this limit. Non-equilibrium systems can beat this limit. However, this requires receptors and their integration time, downstream molecules, and energy. Each resource imposes a fundamental sensing limit, which means that the sensing precision is bounded by the limiting resource and cannot be enhanced by increasing another resource. This result yields a new design principle, namely that of optimal resource allocation in cellular sensing. It states that in an optimally designed sensing system, each resource is equally limiting, so that no resource is wasted. We find that the chemotaxis network of E. coli obeys this principle, indicating a selective pressure for the efficient design of cellular sensing systems.

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Pieter Rein ten Wolde, AMOLF Amsterdam
Seminar Room TP 0.03
Contact: Johannes Berg