Genomic Variations Underlying Speciation and Niche Specialization of Shewanella baltica.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
Auchtung, Jennifer M
Konstantinidis, Konstantinos T
Höfle, Manfred G
Tiedje, James M
MetadataShow full item record
AbstractShewanella baltica was the dominant culturable nitrate-reducing bacterium in the eutrophic and strongly stratified Baltic Sea in the 1980s, where it primarily inhabited the oxic-anoxic transition zone. The genomic structures of 46 of these isolates were investigated through comparative genomic hybridization (CGH), which revealed a gradient of genomic similarity, ranging from 65% to as high as 99%. The core genome of the S. baltica species was enriched in anaerobic respiration-associated genes. Auxiliary genes, most of which locate within a few genomic islands (GIs), were nonuniformly distributed among the isolates. Specifically, hypothetical and mobile genetic element (MGE)-associated genes dominated intraclade gene content differences, whereas gain/loss of functional genes drove gene content differences among less related strains. Among the major S. baltica clades, gene signatures related to specific redox-driven and spatial niches within the water column were identified. For instance, genes involved in anaerobic respiration of sulfur compounds may provide key adaptive advantages for clade A strains in anoxic waters where sulfur-containing electron acceptors are present. Genes involved in cell motility, in particular, a secondary flagellar biosynthesis system, may be associated with the free-living lifestyle by clade E strains. Collectively, this study revealed characteristics of genome variations present in the water column and active speciation of S. baltica strains, driven by niche partitioning and horizontal gene transfer (HGT).IMPORTANCE Speciation in nature is a fundamental process driving the formation of the vast microbial diversity on Earth. In the central Baltic Sea, the long-term stratification of water led to formation of a large-scale vertical redoxcline that provided a gradient of environmental niches with respect to the availability of electron acceptors and donors. The region was home to Shewanella baltica populations, which composed the dominant culturable nitrate-reducing bacteria, particularly in the oxic-anoxic transition zone. Using the collection of S. baltica isolates as a model system, genomic variations showed contrasting gene-sharing patterns within versus among S. baltica clades and revealed genomic signatures of S. baltica clades related to redox niche specialization as well as particle association. This study provides important insights into genomic mechanisms underlying bacterial speciation within this unique natural redoxcline.
CitationmSystems. 2019 Oct 15;4(5). pii: 4/5/e00560-19. doi: 10.1128/mSystems.00560-19.
AffiliationHZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany.
PublisherAmerican Society of Microbiology
The following license files are associated with this item:
- Creative Commons
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 4.0 International
- Divergence in Gene Regulation Contributes to Sympatric Speciation of Shewanella baltica Strains.
- Authors: Deng J, Auchtung JM, Konstantinidis KT, Caro-Quintero A, Brettar I, Höfle M, Tiedje JM
- Issue date: 2018 Feb 15
- Stability, genotypic and phenotypic diversity of Shewanella baltica in the redox transition zone of the Baltic Sea.
- Authors: Deng J, Brettar I, Luo C, Auchtung J, Konstantinidis KT, Rodrigues JL, Höfle M, Tiedje JM
- Issue date: 2014 Jun
- Shewanella baltica Ecotypes Have Wide Transcriptional Variation under the Same Growth Conditions.
- Authors: Hambright WS, Deng J, Tiedje JM, Brettar I, Rodrigues JL
- Issue date: 2016 Sep-Oct
- Genomic variation among closely related Vibrio alginolyticus strains is located on mobile genetic elements.
- Authors: Chibani CM, Roth O, Liesegang H, Wendling CC
- Issue date: 2020 May 11
- Shewanella denitrificans sp. nov., a vigorously denitrifying bacterium isolated from the oxic-anoxic interface of the Gotland Deep in the central Baltic Sea.
- Authors: Brettar I, Christen R, Höfle MG
- Issue date: 2002 Nov