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Growing Magnetotactic Bacteria of the Genus Magnetospirillum: Strains MSR-1, AMB-1 and MS-1
Published on: October 17, 2018
Multiple evolutionary origins of magnetotaxis in bacteria
Summary
Magnetotactic bacteria use magnetic particles called magnetosomes for navigation. These bacteria evolved magnetotaxis independently, with iron oxide and iron sulfide types originating from different bacterial groups.
Area of Science:
- Microbiology
- Biophysics
- Evolutionary Biology
Background:
- Magnetosomes are membrane-bound magnetic crystals found in magnetotactic bacteria.
- These particles enable bacteria to orient along Earth's geomagnetic field lines.
- Magnetotactic bacteria can contain either iron oxide or iron sulfide magnetosomes.
Purpose of the Study:
- To investigate the evolutionary origins of magnetotaxis in bacteria.
- To determine the phylogenetic relationships of iron oxide and iron sulfide magnetotactic bacteria.
- To ascertain whether magnetotaxis evolved once or multiple times.
Main Methods:
- Phylogenetic analysis using small subunit ribosomal RNA (rRNA) gene sequences.
- Comparison of genetic data from cultured and uncultured magnetotactic bacteria.
- Taxonomic classification within the domain Bacteria.
Main Results:
- Iron oxide magnetotactic bacteria are phylogenetically linked to a specific subgroup within Proteobacteria.
- Iron sulfide magnetotactic bacteria are related to dissimilatory sulfate-reducing bacteria in the delta subdivision of Proteobacteria.
- These distinct phylogenetic associations were observed in both cultured and uncultured species.
Conclusions:
- Magnetotaxis in bacteria is polyphyletic, meaning it arose independently in different lineages.
- The evolution of iron oxide-based and iron sulfide-based magnetotaxis occurred separately.
- This suggests convergent evolution of magnetotaxis in the bacterial domain.
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