Extrachromosomal DNA of the Symbiont<i>Sodalis glossinidius</i>

Darby, Alistair C.; Lagnel, Jacques; Matthew, Caroline Zoe; Bourtzis, Kostas; Maudlin, I.; Welburn, Susan C.

doi:10.1128/jb.187.14.5003-5007.2005

Cited by 31 publications

(24 citation statements)

References 22 publications

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“…Among nonpathogenic arthropod endosymbionts, some but not all species of Buchnera carry plasmids encoding proteins involved in the biosynthesis of amino acids that are deficient in the phloemsap diet of the host aphid (50). Genome sequencing of an obligate endosymbiont, Wigglesworthia glossinidia (2), and a secondary symbiont, Sodalis glossinidius (1,14), of blood-feeding tsetse flies (Diptera: Glossinidae) revealed the presence of plasmids of undefined biological significance. Within the Rickettsiales, a plasmid has been described only for R. felis isolate California 2, a rickettsial endosymbiont of fleas (32).…”

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confidence: 99%

Transposon Insertion Reveals pRM, a Plasmid ofRickettsia monacensis

Baldridge

Burkhardt

Felsheim

et al. 2007

Appl Environ Microbiol

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Until the recent discovery of pRF in Rickettsia felis, the obligate intracellular bacteria of the genus Rickettsia (Rickettsiales: Rickettsiaceae) were thought not to possess plasmids. We describe pRM, a plasmid from Rickettsia monacensis, which was detected by pulsed-field gel electrophoresis and Southern blot analyses of DNA from two independent R. monacensis populations transformed by transposon-mediated insertion of coupled green fluorescent protein and chloramphenicol acetyltransferase marker genes into pRM. Two-dimensional electrophoresis showed that pRM was present in rickettsial cells as circular and linear isomers. The 23,486-nucleotide (31.8% G/C) pRM plasmid was cloned from the transformant populations by chloramphenicol marker rescue of restriction enzyme-digested transformant DNA fragments and PCR using primers derived from sequences of overlapping restriction fragments. The plasmid was sequenced. Based on BLAST searches of the GenBank database, pRM contained 23 predicted genes or pseudogenes and was remarkably similar to the larger pRF plasmid. Two of the 23 genes were unique to pRM and pRF among sequenced rickettsial genomes, and 4 of the genes shared by pRM and pRF were otherwise found only on chromosomes of R. felis or the ancestral group rickettsiae R. bellii and R. canadensis. We obtained pulsed-field gel electrophoresis and Southern blot evidence for a plasmid in R. amblyommii isolate WB-8-2 that contained genes conserved between pRM and pRF. The pRM plasmid may provide a basis for the development of a rickettsial transformation vector.

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mentioning

confidence: 99%

Transposon Insertion Reveals pRM, a Plasmid ofRickettsia monacensis

Baldridge

Burkhardt

Felsheim

et al. 2007

Appl Environ Microbiol

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“…Based on our analysis, we hypothesize that pSOG3 is an extrachromosomal element that arose from the integration of two distinct ancestral phage genomes and subsequently degenerated in the adaptation towards symbiosis. Another sequence containing phage-related genes (pSG3) has been obtained from an S. glossinidius strain isolated from Glossina palpalis palpalis (4). It comprises only about 40% of the pSOG3 genome (Fig.…”

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A Possible Heterodimeric Prophage-Like Element in the Genome of the Insect EndosymbiontSodalis glossinidius

et al. 2007

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“…The Sodalis chromosome contains homologues of at least two complete ABC transport systems that may mediate highaffinity iron acquisition, in addition to the plasmid-encoded ABC transport system for the achromobactin siderophore (14,45). Although this is less than what is typically seen in freeliving pathogenic bacteria, it is significantly more than what is seen in the genomes of bacteria engaged in more intimate and, often, more coevolved associations.…”

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confidence: 66%

Regulation of High-Affinity Iron Acquisition Homologues in the Tsetse Fly SymbiontSodalis glossinidius

et al. 2010

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Sodalis glossinidius is a facultative intracellular bacterium that is a secondary symbiont of the tsetse fly (Diptera: Glossinidae). Since studies with other facultative intracellular bacteria have shown that high-affinity iron acquisition genes are upregulated in vivo, we investigated the regulation of several Sodalis genes that encode putative iron acquisition systems. These genes, SG1538 (hemT) and SG1516 (sitA), are homologous to genes encoding periplasmic heme and iron/manganese transporters, respectively. hemT promoter-and sitA promoter-gfp fusions were constructed, and in both Escherichia coli and Sodalis backgrounds, expression levels of these fusions were higher when the bacteria were grown in iron-limiting media than when the bacteria were grown in iron-replete media. The Sodalis promoters were tested for iron regulation in an E. coli strain that lacks the fur gene, which encodes the iron-responsive transcriptional repressor Fur. Expression of the promoter-gfp fusions in the E. coli fur mutant was constitutively high in both iron-replete and iron-deplete media, and addition of either Shigella flexneri fur or Sodalis fur to a plasmid restored normal regulation. A Sodalis fur mutant was constructed by intron mutagenesis, and semiquantitative reverse transcription-PCR (RT-PCR) showed that iron repression of sitA expression was also abolished in this strain. In vivo expression analysis showed that hemT and sitA are expressed when Sodalis is within tsetse fly hosts, suggesting a biological role for these genes when Sodalis is within the tsetse fly.

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Extrachromosomal DNA of the SymbiontSodalis glossinidius

Cited by 31 publications

References 22 publications

Transposon Insertion Reveals pRM, a Plasmid ofRickettsia monacensis

Transposon Insertion Reveals pRM, a Plasmid ofRickettsia monacensis

A Possible Heterodimeric Prophage-Like Element in the Genome of the Insect EndosymbiontSodalis glossinidius

Regulation of High-Affinity Iron Acquisition Homologues in the Tsetse Fly SymbiontSodalis glossinidius

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