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Stochastic switching as a survival strategy in fluctuating environments
Murat Acar1, Jerome T Mettetal, Alexander van Oudenaarden
1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. avano@mit.edu
Nature Genetics
|March 26, 2008
Summary
Cells can optimize fitness in changing environments by switching between phenotypes. The optimal switching rate depends on how quickly the environment changes, with faster switching beneficial in rapidly fluctuating conditions.
Area of Science:
- Population and evolutionary biology
- Microbial ecology
- Systems biology
Background:
- Populations face challenges in fluctuating environments.
- Phenotypic switching can enhance population fitness by ensuring adaptability.
- Stochastic gene expression drives phenotypic transitions.
Purpose of the Study:
- To experimentally investigate the impact of phenotypic switching rates on population growth.
- To determine how environmental fluctuation frequency influences the advantage of different switching rates.
Main Methods:
- Utilized the galactose utilization network of Saccharomyces cerevisiae.
- Engineered a yeast strain with stochastic gene expression for random phenotype transitions.
- Compared population growth rates of fast-switching versus slow-switching strains under varying environmental change frequencies.
Main Results:
- Fast-switching populations showed superior growth in rapidly fluctuating environments.
- Slow-switching populations demonstrated better growth in environments with rare changes.
- Demonstrated a direct correlation between switching rate and environmental change frequency.
Conclusions:
- Phenotypic switching is a viable strategy for optimizing population fitness in dynamic environments.
- Cells can adapt by tuning inter-phenotype switching rates to match environmental change frequencies.
- This study provides insights into evolutionary adaptation mechanisms in fluctuating conditions.
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