Related Experiment Video
Updated: Mar 27, 2026

Sealable Femtoliter Chamber Arrays for Cell-free Biology
Published on: March 11, 2015
Dynamics of simple gene-network motifs subject to extrinsic fluctuations
Elijah Roberts1, Shay Be'er2, Chris Bohrer1
1Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Abstract:
Cellular processes do not follow deterministic rules; even in identical environments genetically identical cells can make random choices leading to different phenotypes. This randomness originates from fluctuations present in the biomolecular interaction networks. Most previous work has been focused on the intrinsic noise (IN) of these networks. Yet, especially for high-copy-number biomolecules, extrinsic or environmental noise (EN) has been experimentally shown to dominate the variation. Here, we develop an analytical formalism that allows for calculation of the effect of EN on gene-expression motifs. We introduce a method for modeling bounded EN as an auxiliary species in the master equation. The method is fully generic and is not limited to systems with small EN magnitudes. We focus our study on motifs that can be viewed as the building blocks of genetic switches: a nonregulated gene, a self-inhibiting gene, and a self-promoting gene. The role of the EN properties (magnitude, correlation time, and distribution) on the statistics of interest are systematically investigated, and the effect of fluctuations in different reaction rates is compared. Due to its analytical nature, our formalism can be used to quantify the effect of EN on the dynamics of biochemical networks and can also be used to improve the interpretation of data from single-cell gene-expression experiments.
More Related Videos
10:44Inherent Dynamics Visualizer, an Interactive Application for Evaluating and Visualizing Outputs from a Gene Regulatory Network Inference Pipeline
Published on: December 7, 2021
08:25Continuous Measurement of Biological Noise in Escherichia Coli Using Time-lapse Microscopy
Published on: April 27, 2021
Related Concept Videos
Mutation, Gene Flow, and Genetic Drift
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon...
Structure of a Gene
However, only 1% of the DNA is composed of genes that encode proteins; the rest, 99% is non-coding DNA. This non-coding DNA performs...
Gene Evolution - Fast or Slow?
In contrast, regions which code...
Gene Evolution - Fast or Slow?
Entropy Changes Accompanying Specific Processes