Appendix 4—figure 2. Comparison of convergence for low and high mRNA levels by way of mature-protein and mature-mature reporters.

Low level corresponds to mean nascent mRNA level of 0.5, and mean mature mRNA level of 5. High level corresponds to mean nascent mRNA level of 5, and mean mature mRNA level of 50. In both cases the simulated genes are constitutive and noise is on all parameters except for ${\delta }_M=1$. The noise on $K_N$ has squared coefficient of variation equal to 0.2, which is shown as the red horizontal line. Our theory shows that mature-protein reporters will return an overshoot that is negligible in the high-output gene (the blue horizontal line), but larger in the low output gene (light blue horizontal line); these values are calculated in the text. (A) Comparison of convergence for low and high mRNA levels over the first 2000 samples. (B) Convergence of the ${\eta }^2$ estimate over $20,000$ samples in the case of the low-output gene only. Two examples of each are given, to show the variation in behaviour.