Comparative genomic analysis provides insights into the evolution and niche adaptation of marine Magnetospira sp. QH-2 strain
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Boyang Ji
- Function : Author
- PersonId : 768261
- ORCID : 0000-0002-7269-4342
Pascal Arnoux
- Function : Author
- PersonId : 743398
- IdHAL : pascal-arnoux
- ORCID : 0000-0003-4609-4893
- IdRef : 08652819X
François Alberto
- Function : Author
- PersonId : 20097
- IdHAL : francois-alberto
- ORCID : 0000-0002-0596-6694
- IdRef : 075944154
Dorothée Murat
- Function : Author
- PersonId : 756357
- ORCID : 0000-0001-5809-9267
Wei-Jia Zhang
- Function : Author
- PersonId : 779909
- ORCID : 0000-0003-2785-6434
Nicolas Ginet
- Function : Author
- PersonId : 180306
- IdHAL : nicolas-ginet
- ORCID : 0000-0002-5544-4376
- IdRef : 195952073
Monique Sabaty
- Function : Author
- PersonId : 750866
- IdHAL : monique-sabaty
- ORCID : 0000-0002-1399-6922
Nathalie Pradel
- Function : Author
- PersonId : 19909
- IdHAL : nathalie-pradel
Jiesheng Tian
- Function : Author
Lichen Zhang
- Function : Author
- PersonId : 779910
- ORCID : 0000-0002-7810-9941
- IdRef : 161207456
Bernard Henrissat
- Function : Author
- PersonId : 833340
Long-Fei Wu
- Function : Author
- PersonId : 738756
- IdHAL : long-fei-wu
- ORCID : 0000-0002-8993-4138
- IdRef : 034251782
Abstract
Magnetotactic bacteria (MTB) are capable of synthesizing intracellular organelles, the magnetosomes, that are membrane-bounded magnetite or greigite crystals arranged in chains. Although MTB are widely spread in various ecosystems, few axenic cultures are available, and only freshwater Magnetospirillum spp. have been genetically analysed. Here, we present the complete genome sequence of a marine magnetotactic spirillum, Magnetospira sp. QH-2. The high number of repeats and transposable elements account for the differences in QH-2 genome structure compared with other relatives. Gene cluster synteny and gene correlation analyses indicate that the insertion of the magnetosome island in the QH-2 genome occurred after divergence between freshwater and marine magnetospirilla. The presence of a sodium-quinone reductase, sodium transporters and other functional genes are evidence of the adaptive evolution of Magnetospira sp. QH-2 to the marine ecosystem. Genes well conserved among freshwater magnetospirilla for nitrogen fixation and assimilatory nitrate respiration are absent from the QH-2 genome. Unlike freshwater Magnetospirillum spp., marine Magnetospira sp. QH-2 neither has TonB and TonB-dependent receptors nor does it grow on trace amounts of iron. Taken together, our results show a distinct, adaptive evolution of Magnetospira sp. QH-2 to marine sediments in comparison with its closely related freshwater counterparts.