title: Deep sea immunity: unveiling immune constituents from the hydrothermal vent mussel Bathymodiolus azoricus.
abstract: Marine molluscs are subjected to constant microbial threats in their natural habitats. As a result, they represent suitable models for the study of the molecular mechanisms that govern defense reactions in marine organisms. To understand humoral and cellular defense reactions in animals defying extreme physical and chemical conditions we set out to investigate the deep sea hydrothermal vent mussel Bathymodiolus azoricus found in abundance at the Mid-Atlantic Ridge. In the present study, hemocytes were stimulated with compounds of microbial origin and cellular morphological alterations as well as the production of superoxide assessed. Consequently, zymosan, glucan and peptidoglycan were considered as potent inducers of cellular reactions for inducing drastic cell morphology changes and high levels of superoxide production. Furthermore, we have presented for the first time in a deep sea hydrothermal vent animal, molecular evidence of the Rel-homology domain, a conserved motif present in all members of the Rel/nuclear-factor NF-kappaB family. Additionally we have demonstrated the occurrence of the antibacterial gene mytilin in Bathymodiolus azoricus gill tissues. Our results support the premise of an evolutionary conserved innate immune system in Bathymodiolus. Such system is seemingly homologous to that of Insects and other Bivalves and may involve the participation of NF-kappaB transcription factors and antibacterial genes.
authors.affiliation: IMAR/Department of Oceanography and Fisheries, Genetics and Molecular Laboratory, University of the Azores, Rua Comendador Fernando da Costa, 9901-862 Horta, Portugal. raul@notes.horta.uac.pt
authors.forename: Raul
authors.initials: R
authors.lastname: Bettencourt
authors.forename: Philippe
authors.initials: P
authors.lastname: Roch
authors.forename: Sergio
authors.initials: S
authors.lastname: Stefanni
authors.forename: Domitília
authors.initials: D
authors.lastname: Rosa
authors.forename: Ana
authors.initials: A
authors.lastname: Colaço
authors.forename: Ricardo Serrão
authors.initials: RS
authors.lastname: Santos
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics; D007113:Immunity, Innate / Q000502:physiology*; D007155:Immunologic Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D049879:Mytilidae / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism; D009792:Oceans and Seas; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D023181:Antimicrobial Cationic Peptides; D007155:Immunologic Factors; D016328:NF-kappa B; D012333:RNA, Messenger; C408470:mytilin