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  • Open Access

When Many Noisy Genes Optimize Information Flow

Nicholas Lawson* and William Bialek†

  • Joseph Henry Laboratories of Physics and Lewis–Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA

  • *Contact author: nlawson@g.harvard.edu
  • †Contact author: wbialek@princeton.edu
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PRX Life 4, 033025 – Published 8 September, 2026

DOI: https://doi.org/10.1103/f8vw-ddpv

Abstract

It often is emphasized that gene expression is noisy. A seemingly contradictory view is that control mechanisms have been optimized to squeeze as much information as possible out of a limited number of molecules. Here we revisit these issues in a simple model where a single transcription factor (TF) controls a large number of target genes. We include only the physically required noise sources—random arrival of TFs at their targets and counting noise in the synthesis and degradation of messenger RNA (mRNA). If the cell has a limited total number of mRNA molecules, then the capacity to transmit information about TF concentration is maximized when these resources are distributed across the largest possible number of target genes. To realize this capacity the distribution of TF concentrations must be biased toward smaller values. Thus, in some limits, information transmission is optimized when individual expression levels are noisy. In addition, the dependence of information transmission on the parameters of this multigene system has a “sloppy” spectrum, so that optimal performance can coexist with substantial variability.

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PRX Life 4, 033025– Published 8 September, 2026
  • Received 2 February 2026
  • Accepted 3 August 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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