Genetic Redundancies Enhance Information Transfer in Noisy Regulatory Circuits
Fig 5
Genetic heterogeneity among redundant copies amplifies information transfer.
Variation in the biochemical features of the constituent threshold devices (represented by the different colors of the devices, here bistable units, N = 5) leads to a maximum in mutual information (MI). We consider random threshold values drawn from a Gaussian distribution whose standard deviation determines the degree of heterogeneity (see Materials and Methods, no heterogeneity corresponds to a very low, i.e., 10−4, but nonzero value due the log scale of the x axis). The inset indicates the peak differential MI (i.e., the difference between the largest value of MI with heterogeneity and the value of MI without it) for varying noise levels. This reveals how a situation of stronger intrinsic noise contributes to reduce the improving effect on MI of heterogeneous units (the main plot corresponds to an intrinsic noise amplitude equal to 0.16).