Intercellular Variability in Protein Levels from Stochastic Expression and Noisy Cell Cycle Processes
Fig 6
Contributions from different noise sources as a function of the timing of genome duplication for .
Different noise components in Eq (46) are plotted as a function of β, which represents the fraction of time within the cell cycle at which gene duplication occurs. The mean protein level is held constant by simultaneously changing the transcription rate kx. Noise levels are normalized by their respective value at β = 0. The noise contribution from partitioning errors is maximized at β ≈ 0.6. In contrast, the contribution from stochastic expression is minimum at β ≈ 0.6. The extrinsic noise contribution from random gene-duplication and cell-division events is maximum at β ≈ 0.2 and minimum at β ≈ 0.8. For this plot, the mean of the protein is 170 molecules per cell; and the bursts are geometrically distributed with 〈B〉 = 10.