title: Phylogenetic analysis of the 16S rDNA of the cytoplasmic bacterium Wolbachia from the novel host Folsomia candida (Hexapoda, Collembola) and its implications for wolbachial taxonomy.
abstract: Wolbachia pipientis are intracellular, transovarially inherited alpha-Proteobacteria in invertebrates. Four major Wolbachia groups exist: A, B (contained in divergent arthropods), C and D (harbored by Nematoda). By means of transmission electron microscopy, we observed Wolbachia-like bacteria in a primitive insect, Folsomia candida (Hexapoda, Collembola, Isotomidae). 16S rDNA analysis proved them to constitute a novel lineage, henceforth named group E, in the wolbachial phylogenetic tree. It shares 97.8% 16S rDNA homology with its nearest neighbors, groups A and B, which diverged from it more recently. We propose (i) a new taxon E for the Wolbachia strain in F. candida, (ii) that the single-described Wolbachia pipientis fall apart into at least three species: C, D and the large E-A-B complex. F. candida's group E Wolbachia rekindle the question about invasive capacities of free-living ancestral wolbachiae and horizontal transfer.
authors.affiliation: University of Ghent, Department of Physiology, Biochemistry and Microbiology, Laboratory of Microbiology, K.L. Ledeganckstraat 35, B-9000, Ghent, Belgium. tom.vandekerckhove@rug.ac.be
authors.forename: T T
authors.initials: TT
authors.lastname: Vandekerckhove
authors.forename: S
authors.initials: S
authors.lastname: Watteyne
authors.forename: A
authors.initials: A
authors.lastname: Willems
authors.forename: J G
authors.initials: JG
authors.lastname: Swings
authors.forename: J
authors.initials: J
authors.lastname: Mertens
authors.forename: M
authors.initials: M
authors.lastname: Gillis
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics*; D005260:Female; D007313:Insecta / Q000382:microbiology*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D020577:Wolbachia / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S