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High-Resolution Comparison of Bacterial Conjugation Frequencies
Published on: January 10, 2019
Why do bacterial plasmids carry some genes and not others?
1Smithsonian Tropical Research Institute, Costa Rica.
Plasmid
|May 1, 1989
Summary
Bacterial genes for optional traits are often on plasmids, not chromosomes, because they provide local adaptations. A new model shows these genes reproduce better on plasmids due to horizontal mobility.
Area of Science:
- Microbiology
- Evolutionary Biology
- Genetics
Background:
- Traditional explanations for plasmid-borne genes rely on outdated natural selection theories.
- Existing models fail to account for ubiquitous plasmid-associated traits in some species.
Purpose of the Study:
- To propose a new model for plasmid evolution.
- To explain the prevalence of plasmid-borne genes conferring local adaptations.
Main Methods:
- Developed a "local adaptation" model for plasmid evolution.
- Applied modern selection theory across gene, plasmid, cell, and clone reproduction levels.
Main Results:
- Demonstrated that traits associated with plasmids confer adaptations to restricted environments.
- Showed that genes for local adaptations reproduce more successfully on plasmids than chromosomes.
Conclusions:
- Plasmids facilitate the reproduction of genes conferring local adaptations.
- Horizontal mobility of plasmids is key to the success of locally adaptive genes.
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