Multiple Stochastic Point Processes in Gene Expression
- 83 Downloads
We generalize the idea of multiple-stochasticity in chemical reaction systems to gene expression. Using Chemical Langevin Equation approach we investigate how this multiple-stochasticity can influence the overall molecular number fluctuations. We show that the main sources of this multiple-stochasticity in gene expression could be the randomness in transcription and translation initiation times which in turn originates from the underlying bio-macromolecular recognition processes such as the site-specific DNA-protein interactions and therefore can be internally regulated by the supra-molecular structural factors such as the condensation/super-coiling of DNA. Our theory predicts that (1) in case of gene expression system, the variances (φ) introduced by the randomness in transcription and translation initiation-times approximately scales with the degree of condensation (s) of DNA or mRNA as φ ∝ s −6. From the theoretical analysis of the Fano factor as well as coefficient of variation associated with the protein number fluctuations we predict that (2) unlike the singly-stochastic case where the Fano factor has been shown to be a monotonous function of translation rate, in case of multiple-stochastic gene expression the Fano factor is a turn over function with a definite minimum. This in turn suggests that the multiple-stochastic processes can also be well tuned to behave like a singly-stochastic point processes by adjusting the rate parameters.
KeywordsMultiple stochastic point processes Gene expression Time dependent rates
Unable to display preview. Download preview PDF.
- 12.Raser, J.M., O’Shea, E.K.: Noise in gene expression: origins, consequences, and control. Nature 309, 2010–2013 (2005) Google Scholar
- 14.Risken, H.: Fokker–Plank Equations. Springer, Berlin (1992) Google Scholar
- 15.Gardiner, C.W.: Handbook of Stochastic Methods. Springer, Berlin (2002) Google Scholar
- 16.Lewin, B.: Genes VIII. Oxford University Press, London (2004) Google Scholar