The early phase of a bacterial insertion sequence infection
Manuel Bichsel1, Andrew D Barbour, Andreas Wagner
1Department of Biochemistry, University of Zürich, CH-8057 Zürich, Switzerland. m.bichsel@bioc.uzh.ch
Theoretical Population Biology
|September 7, 2010
Summary
Horizontal gene transfer enables bacterial insertion sequences to persist, despite low infection success. Successful infections are slow and erratic, with extinction being common.
Area of Science:
- Microbiology
- Evolutionary Biology
- Genetics
Background:
- Bacterial insertion sequences (IS) are mobile genetic elements.
- Their persistence in bacterial populations is not fully understood.
- It is unclear if IS require beneficial effects or if horizontal gene transfer (HGT) is sufficient.
Purpose of the Study:
- To investigate the early infection dynamics of bacterial insertion sequences.
- To determine the conditions under which IS can successfully infect and persist.
Main Methods:
- Utilized branching process models.
- Simulated the critical early phase of IS infection.
Main Results:
- The probability of successful IS infection is low.
- Infection success depends linearly on the balance between HGT rate and IS fitness cost.
- Extinction times for unsuccessful infections are short; successful infections take a long time to establish.
Conclusions:
- Horizontal gene transfer is sufficient for the persistence of bacterial insertion sequences.
- IS infection is an unpredictable and slow process.
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