Speaker
Description
Mutual information is a theoretically grounded metric for quantifying information flow in cellular signaling pathways. However, its measurement requires characterization of the joint distribution of both input and output variables, which is data-intensive and often impractical, particularly when the input is high-dimensional, such as temporal trajectories of signaling molecules.
Here, we present an alternative method that alleviates this requirement using dual reporter systems \cite{nakamura2026} — experimental setups where two conditionally independent reporter copies respond to a shared input signal \cite{elowitz2002}. By extending the extrinsic–intrinsic noise decomposition \cite{elowitz2002}, we derive a mutual information estimator that eliminates the need to measure input distribution. We demonstrate our method on the bacterial chemotactic signaling pathway, where multiple flagellar motors within a single cell serve as natural dual reporters \cite{uchida2022}. We validate the biological relevance of the measured information flow by comparing it with theoretical bounds on sensory information from optimal Bayesian filtering \cite{nakamura2021, mattingly2021}. As modern single-molecule and single-cell measurement techniques increasingly enable simultaneous observation of multiple output copies, our method opens new directions for quantifying information flow across diverse biological systems.
Bibliography
@article{nakamura2026, title = {Quantification of information flow by dual reporter system and its application to bacterial chemotaxis}, author = {Nakamura, Kento and Fukuoka, Hajime and Ishijima, Akihiko and Kobayashi, Tetsuya J.}, journal = {Phys. Rev. Lett.}, pages = {--}, year = {2026}, month = {Feb}, publisher = {American Physical Society}, doi = {10.1103/jrph-wj94}, url = {https://link.aps.org/doi/10.1103/jrph-wj94} }
@article{elowitz2002, title={Stochastic gene expression in a single cell}, author={Elowitz, Michael B and Levine, Arnold J and Siggia, Eric D and Swain, Peter S}, journal={Science}, volume={297}, number={5584}, pages={1183--1186}, year={2002}, publisher={American Association for the Advancement of Science} }
@article{uchida2022, title={The chemoreceptor sensory adaptation system produces coordinated reversals of the flagellar motors on an Escherichia coli cell}, author={Uchida, Yumiko and Hamamoto, Tatsuki and Che, Yong-Suk and Takahashi, Hiroto and Parkinson, John S and Ishijima, Akihiko and Fukuoka, Hajime}, journal={Journal of Bacteriology}, volume={204}, number={12}, pages={e00278--22}, year={2022}, publisher={American Society for Microbiology 1752 N St., NW, Washington, DC} }
@article{nakamura2021, title={Connection between the bacterial chemotactic network and optimal filtering}, author={Nakamura, Kento and Kobayashi, Tetsuya J}, journal={Physical Review Letters}, volume={126}, number={12}, pages={128102}, year={2021}, publisher={APS} }
@article{mattingly2021, title={Escherichia coli chemotaxis is information limited}, author={Mattingly, Henry H and Kamino, Keita and Machta, Benjamin B and Emonet, Thierry}, journal={Nature physics}, volume={17}, number={12}, pages={1426--1431}, year={2021}, publisher={Nature Publishing Group UK London} }
