Related Experiment Video
Updated: Aug 7, 2026
10:46
Gene Digital Circuits Based on CRISPR-Cas Systems and Anti-CRISPR Proteins
Published on: October 18, 2022
Chemical models of genetic toggle switches
Patrick B Warren1, Pieter Rein ten Wolde
1Unilever R&D, Port Sunlight, Bebington, Wirral CH63 3JW, United Kingdom.
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Genetic toggle switches are stabilized by increasing transcription factor numbers, with stability growing exponentially. Biochemical noise reduces stability, but DNA-based mutual exclusion of transcription factors enhances robustness.
Area of Science:
- Biochemistry
- Systems Biology
- Molecular Genetics
Background:
- Genetic toggle switches are crucial for cellular decision-making.
- Understanding their stability is key to predicting cellular behavior.
- Mutual repression between genes forms the basis of these switches.
Purpose of the Study:
- To analyze the stability of chemical models for genetic toggle switches.
- To investigate the relationship between switch stability and molecular noise.
- To explore methods for enhancing the robustness of genetic switches.
Main Methods:
- Mean-field analysis and stochastic simulations of chemical models.
- Application of reactive flux theory and transition state theory.
- Characterization of switch lifetime (tau) and its dependence on molecular numbers (N).
Main Results:
- Switch stability (tau) exhibits exponential growth with the number of transcription factors (N), following tau ~ N(alpha) exp(bN).
- Increased gene expression noise (shot noise, protein production fluctuations) decreases switch stability.
- Mutual exclusion of transcription factors on DNA significantly enhances switch robustness against noise.
Conclusions:
- The lifetime of genetic toggle switches is highly sensitive to the number of involved molecules.
- Biochemical noise poses a challenge to switch stability, but can be mitigated.
- DNA-based architectural arrangements offer a powerful strategy for engineering robust genetic switches.
Related Concept Videos
02:46Genetic Screens
Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options.
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
01:22Switching of BJT
Switching behavior in Bipolar Junction Transistors (BJTs) is a fundamental aspect utilized in various electronic circuits, particularly for digital logic applications like switches and amplifiers. In a typical switching circuit, a BJT alternates between cut-off and saturation modes, corresponding to the "off" and "on" states, respectively, thus behaving like an ideal switch.
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are reverse-biased. The...
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are reverse-biased. The...
02:05DNA as a Genetic Template
Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for...
01:16In-vitro Mutagenesis
To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.
02:00Molecular Models
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...