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Updated: May 30, 2026
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Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Rapid optimization of gene dosage in E. coli using DIAL strains.
Joshua T Kittleson1, Sherine Cheung, J Christopher Anderson
1Department of Bioengineering, University of California, Berkeley, USA. jcanderson@berkeley.edu.
Journal of Biological Engineering
|July 27, 2011
Summary
Synthetic biologists can now rapidly explore gene expression levels using novel DIAL strains. This technology allows plasmids to be maintained at different copy numbers, accelerating genetic circuit optimization and pathway development.
Area of Science:
- Synthetic Biology
- Genetic Engineering
- Molecular Biology
Background:
- Synthetic biologists require tools to rapidly explore gene expression levels and systematically vary genetic circuit dosage.
- Current methods lack efficient ways to investigate gene or circuit dosage effects.
Purpose of the Study:
- To develop a technology enabling plasmids to be maintained at different copy numbers within closely related cells.
- To provide a rapid method for exploring gene or genetic cassette dosage effects.
Main Methods:
- Engineered two sets of strains to constitutively provide trans-acting replication factors (Pi of R6K or RepA of ColE2) at varying doses.
- Developed DIAL (different allele) strains that support corresponding plasmid replication at controlled copy numbers (1-250 copies/cell).
- Demonstrated utility by assessing optimal expression for a violecein biosynthetic pathway.
Main Results:
- DIAL strains enable plasmid replication at constant, tunable copy numbers (1-250 copies/cell) with improved stability.
- Orthogonal replication origins allow co-maintenance of multiple replication factors in a single cell.
- Successfully demonstrated rapid optimization of a model biosynthetic pathway.
Conclusions:
- DIAL strains facilitate rapid optimization of single gene expression levels.
- The technology aids in balancing expression of coupled genetic elements and investigating gene/circuit dosage effects.
- Enables faster development of synthetic metabolic pathways.
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