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Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
Metabolic changes associated with adaptive diversification in Escherichia coli
Mickaël Le Gac1, Michelle D Brazas, Melanie Bertrand
1Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. legac@zoology.ubc.ca
Genetics
|February 5, 2008
Summary
Two bacterial strains evolved distinct metabolic strategies from a common ancestor, adapting to glucose and acetate availability. One strain efficiently consumed glucose, while the other utilized both glucose and acetate, even in low oxygen conditions.
Area of Science:
- Microbial evolution
- Bacterial adaptation
- Metabolic diversification
Background:
- Bacteria evolved in a seasonal environment with glucose and acetate.
- A common ancestor diverged into two distinct bacterial types over 1000 generations.
Purpose of the Study:
- Investigate metabolic modifications during adaptive diversification.
- Compare transcription profiles of ancestral and derived bacterial types.
Main Methods:
- 1000-generation evolution experiment.
- Comparative transcription profiling.
- Analysis of metabolic gene expression.
Main Results:
- Both derived types showed common adaptations: improved translation efficiency, enhanced glucose uptake (mal/lamB genes), and stationary phase transporter upregulation.
- Diversification linked to differential gene expression: TCA cycle, glyoxylate shunt, and acetate metabolism genes were overexpressed in one type, while acetate excretion genes were upregulated in the other.
- One type consumed glucose rapidly without oxygen limitation; the other consumed glucose and acetate slowly, even with oxygen limitation.
Conclusions:
- Competition for carbon and oxygen drove adaptive diversification in Escherichia coli.
- Evolved strains developed distinct metabolic strategies for resource utilization and survival under varying oxygen availability.
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