Fig 4. The nonlinear behavior of the transcription noises.

The transcription kinetics are specified by (43) and (51), and the stage durations vary from 10 to 10⁴ min. (A) The mean m* increases in the cell cycle durations. (B) The noise η²* is about equally sensitive to the variation of the stage durations and decreases from 3 to 0.5 as the stage durations increase. (C) The noise strength Φ* varies widely from 20 to 100 with a highly nonlinear dependance on the stage durations. (D)-(F) The ratios $m_2^{*}/m_1^{*}$, ${\Phi }_2^{*}/{\Phi }_1^{*}\in [1,2]$, and ${\eta }_2^{2*}/{\eta }_1^{2*}\in [0.5,1]$ over most durations. (G)-(I) Φ* is larger than both ${\Phi }_1^{*}$ and ${\Phi }_2^{*}$ but less than ${\Phi }_1^{*}+{\Phi }_2^{*}$ over most durations.