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Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
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Plasmid Transfer in the Ocean - A Case Study from the Roseobacter Group.
Jörn Petersen1, Irene Wagner-Döbler2
1Research Group Plasmids and Protists, Leibniz-Institute DSMZ - German Collection of Microorganisms and Cell CulturesBraunschweig, Germany.
Frontiers in Microbiology
|August 4, 2017
Summary
Horizontal gene transfer (HGT) via plasmids is key for marine bacteria adaptation. This study shows evidence of plasmid transfer between distantly related roseobacters, highlighting HGT
Area of Science:
- Marine microbiology
- Genetics
- Evolutionary biology
Background:
- Plasmid-mediated horizontal gene transfer (HGT) is crucial for marine bacteria adaptation.
- Roseobacters utilize plasmids for essential functions like photosynthesis and antibiotic production.
- Type four secretion systems (T4SS) in roseobacters facilitate inter-genus conjugation in lab settings.
Purpose of the Study:
- To investigate the role of conjugational plasmid transfer in the adaptation of roseobacters.
- To identify and characterize plasmids involved in HGT within the Rhodobacteraceae family.
- To provide evidence for plasmid transfer across biogeographical and phylogenetic barriers.
Main Methods:
- Comparative genomics of plasmids from *Confluentimicrobium naphthalenivorans* NS6T and *Dinoroseobacter shibae* DFL12T.
- Analysis of plasmid replicon stability using RepABC operons (compatibility group -2).
- Principal component analysis of codon usage to assess plasmid-chromosome divergence.
Main Results:
- A 185-kb plasmid from *C. naphthalenivorans* NS6T shows synteny with a 126-kb plasmid from *D. shibae* DFL12T.
- Both plasmids are maintained by homologous RepABC-2 operons and harbor a similar T4SS.
- High plasmid similarity contrasts with distinct chromosomal divergence, indicating neither species is the original host.
- The species inhabit different environments and are phylogenetically distant.
Conclusions:
- This study provides the first clear evidence of conjugational plasmid transfer across biogeographical and phylogenetic barriers in Rhodobacteraceae.
- Conjugative HGT plays a significant role in the adaptation and evolution of marine bacteria.
- The findings underscore the importance of HGT in shaping microbial communities in marine habitats.
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