title: Lateral gene transfer between obligate intracellular bacteria: evidence from the Rickettsia massiliae genome.
abstract: Rickettsia massiliae is a tick-borne obligate intracellular alpha-proteobacteria causing spotted fever in humans. Here, we present the sequence of its genome, comprising a 1.3-Mb circular chromosome and a 15.3-kb plasmid. The chromosome exhibits long-range colinearity with the other Spotted Fever Group Rickettsia genomes, except for a large fragment specific to R. massiliae that contains 14 tra genes presumably involved in pilus formation and conjugal DNA transfer. We demonstrate that the tra region was acquired recently by lateral gene transfer (LGT) from a species related to Rickettsia bellii. Further analysis of the genomic sequences identifies additional candidates of LGT between Rickettsia. Our study indicates that recent LGT between obligate intracellular Rickettsia is more common than previously thought.
authors.affiliation: Structural and Genomic Information Laboratory, CNRS-UPR 2589, Institut de Biologie Structurale et Microbiologie, IFR 88, Parc Scientifique de Luminy, 13288 Marseille Cedex 9, France. guillaume.blanc@igs.cnrs-mrs.fr
authors.forename: Guillaume
authors.initials: G
authors.lastname: Blanc
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ogata
authors.forename: Catherine
authors.initials: C
authors.lastname: Robert
authors.forename: Stéphane
authors.initials: S
authors.lastname: Audic
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Claverie
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D005810:Multigene Family; D010802:Phylogeny; D012281:Rickettsia / Q000235:genetics*; D012282:Rickettsia Infections / Q000235:genetics