First published 2 September 2013
Effects of inducer intake kinetics on the dynamics of gene expression
Huy Tran, Andre S. Ribeiro
Many genes are only active following the intake of an inducer by the cell, via passive diffusive, positive, or negative feedback intake mechanisms. Based on measurements of the in vivo kinetics of intake and subsequent transcription events in Escherichia coli, we use stochastic models to investigate how the kinetics of intake affects both transient and nearequilibrium dynamics of gene expression. We find that the intake kinetics affects mean and variability of the transient time to reach the steady state of proteins numbers and also the degree of fluctuations in these numbers. Fluctuations in the extracellular number of inducers affects the variability of protein numbers at steady state in a degree that differs with the intake kinetics. Finally, changing the intake kinetics of an inducer of a genetic switch allows tuning the bias in the choice of noisy attractor. We conclude that the kinetics of inducer intake affects transient and near-equilibrium gene expression dynamics and, consequently, the phenotypic diversity of organisms in fluctuating environments.