Princeton University, USA
Trading bits in the readout from a genetic network
In genetic networks, information of relevance to the organism is represented by the concentrations of transcription factor molecules. In order to extract this information the cell must effectively “measure” these concentrations, but there are physical limits to the precision of these measurements. In this talk, I will discuss results from a recent preprint with collaborators, where we apply this question to the gap gene network in the early fly embryo as an example. We argue that cells in the embryo can extract all the available information about their position, but only if the concentration measurements approach the physical limits to information capacity. These limits necessitate the observed proliferation of enhancer elements with sensitivities to combinations of transcription factors, but fine tuning of the parameters of these multiple enhancers is not required.