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06:03
Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat
Published on: September 20, 2016
Does experimental evolution reflect patterns in natural populations? E. coli strains from long-term studies compared
V Souza1, M Travisano, P E Turner
1Departamento de Ecologia Evolutiva, Instituto de Ecología, Universidad Nacional Autonoma de México, DF. souza@servidor.unam.mx
Antonie Van Leeuwenhoek
|November 27, 2002
Summary
Experimental evolution with periodic recombination closely mimics natural evolution in E. coli. Just 1,000 generations rapidly altered linkage disequilibrium, mirroring wild strains and suggesting host adaptation drives population structure.
Area of Science:
- Evolutionary biology
- Microbial genetics
- Population genetics
Background:
- The evolutionary history of Escherichia coli (E. coli) involves lateral gene insertion, creating a genome patchwork.
- Understanding the impact of recombination and gene flow on microbial population structure is crucial.
Purpose of the Study:
- To investigate if experimental evolution can replicate natural evolutionary patterns observed in E. coli.
- To analyze the role of recombination and host-specific selection in shaping E. coli population structure.
Main Methods:
- Experimental evolution of E. coli populations subjected to periodic recombination with immigrant genotypes.
- Analysis of linkage disequilibrium values over 1,000 generations.
- Comparison of experimental population data with genetic data from wild E. coli strains.
Main Results:
- Experimental evolution rapidly shifted linkage disequilibrium values, mimicking those found in wild E. coli.
- The experimental E. coli chromosome exhibited a patchwork structure, with regions of high recombination and clonal sites.
- A population model was proposed where gene flow and host-specific selection act as key drivers of genetic variation.
Conclusions:
- Experimental evolution effectively recapitulates key aspects of natural E. coli evolution, including linkage disequilibrium patterns.
- Host-specific adaptation and selective pressures (selective sieves) likely play a significant role in the ecotypic structure of wild E. coli populations.
- Gene flow and migration are vital sources of genetic variation in E. coli populations.
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