title: Abundant toxin-related genes in the genomes of beneficial symbionts from deep-sea hydrothermal vent mussels.
abstract: Bathymodiolus mussels live in symbiosis with intracellular sulfur-oxidizing (SOX) bacteria that provide them with nutrition. We sequenced the SOX symbiont genomes from two Bathymodiolus species. Comparison of these symbiont genomes with those of their closest relatives revealed that the symbionts have undergone genome rearrangements, and up to 35% of their genes may have been acquired by horizontal gene transfer. Many of the genes specific to the symbionts were homologs of virulence genes. We discovered an abundant and diverse array of genes similar to insecticidal toxins of nematode and aphid symbionts, and toxins of pathogens such as Yersinia and Vibrio. Transcriptomics and proteomics revealed that the SOX symbionts express the toxin-related genes (TRGs) in their hosts. We hypothesize that the symbionts use these TRGs in beneficial interactions with their host, including protection against parasites. This would explain why a mutualistic symbiont would contain such a remarkable 'arsenal' of TRGs.
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors.forename: Lizbeth
authors.initials: L
authors.lastname: Sayavedra
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Kleiner
authors.affiliation: Institute of Pharmacy, Ernst-Moritz-Arndt-University, Greifswald, Germany.
authors.forename: Ruby
authors.initials: R
authors.lastname: Ponnudurai
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Wetzel
authors.affiliation: Genoscope - Centre National de Séquençage, Commissariat à l'énergie atomique et aux énergies alternatives, Evry, France.|Metabolic Genomics Group, Commissariat à l'énergie atomique et aux énergies alternatives, Evry, France.|University of Évry-Val d'Essonne, Evry, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Pelletier
authors.affiliation: Genoscope - Centre National de Séquençage, Commissariat à l'énergie atomique et aux énergies alternatives, Evry, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Barbe
authors.affiliation: Marine Genomics Unit, Okinawa Institute of Science and Technology, Onna, Japan.
authors.forename: Nori
authors.initials: N
authors.lastname: Satoh
authors.affiliation: Marine Genomics Unit, Okinawa Institute of Science and Technology, Onna, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Shoguchi
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Fink
authors.affiliation: Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
authors.forename: Corinna
authors.initials: C
authors.lastname: Breusing
authors.affiliation: Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
authors.forename: Thorsten Bh
authors.initials: TB
authors.lastname: Reusch
authors.affiliation: Institute of Clinical Molecular Biology, Kiel, Germany.
authors.forename: Philip
authors.initials: P
authors.lastname: Rosenstiel
authors.affiliation: Institute of Clinical Molecular Biology, Kiel, Germany.
authors.forename: Markus B
authors.initials: MB
authors.lastname: Schilhabel
authors.affiliation: Institute of Marine Biotechnology, Greifswald, Germany.|Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany.
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.affiliation: Institute of Pharmacy, Ernst-Moritz-Arndt-University, Greifswald, Germany.|Institute of Marine Biotechnology, Greifswald, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schweder
authors.affiliation: Institute of Pharmacy, Ernst-Moritz-Arndt-University, Greifswald, Germany.|Institute of Marine Biotechnology, Greifswald, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Markert
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.|University of Bremen, Bremen, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Dubilier
authors.affiliation: Max Planck Institute for Marine Microbiology, Bremen, Germany.
authors.forename: Jillian M
authors.initials: JM
authors.lastname: Petersen
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000382:microbiology*; D001419:Bacteria / Q000235:genetics* / Q000254:growth & development; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D049872:Bivalvia / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D016680:Genome, Bacterial; D060086:Hydrothermal Vents; D008969:Molecular Sequence Data; D020543:Proteome / Q000032:analysis; D012623:Seawater; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D020543:Proteome
keywords: Bathymodiolus; evolutionary biology; genomics; infectious disease; microbiology; sulfur oxidizer; symbiosis; toxins