Shadow enhancers mediate trade-offs between transcriptional noise and fidelity
Fig 4
In superadditive networks, more enhancers decrease noise and fidelity.
(A) Superadditivity is implemented in our model by linearly increasing kon rates and linearly decreasing koff rates. In this case d2, the rate of decrease for koff, was chosen to be 0.4 for T1 and 0.3 for T2. Meanwhile d1, the rate of increase for kon, was chosen to be 0.01 for both T1 and T2 (B) Unlike in the subadditive case, enhancer numbers decrease transcriptional fidelity and also decrease noise. The distribution of binding sites does not affect either the noise or the fidelity all else being constant. (C) Plots showing the relationship between binding site numbers and transcriptional noise for two superadditive enhancers. Increasing binding site numbers leads to less noise in gene expression.