Trading information among multiple variables*

Information relevant to cellular function is represented in the concentrations of signaling molecules, including the transcription factors that control gene expression. The amount of relevant information that can be extracted is limited by the precision or information capacity of the mechanisms that respond to changing concentrations.  We have explored this tradeoff in the context of early events in the fruit fly embryo [1] and shown that there are universal features to this tradeoff in limits that are relevant to the embryo [2].  Those results showed that the capacity needed to extract the observed level of positional information in the embryo exceeds what is plausible for a single “readout mechanism’’ or enhancer element.  Here we consider more explicitly how information can be extracted by parallel readout mechanisms, each with limited capacity.  This analysis could lead to a theory for the functional behavior of multiple enhancers in the control of gene expression.  Initial results point to the importance of non-monotonicity and combinatorial responses.

[1] M Bauer et al, Proc Natl Acad Sci (USA) 118, e2109011118 (2021)

[2] M Bauer and W Bialek, arXiv:2212.12471 [physics.bio-ph] (2022).