title: Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas.
abstract: Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences inCrassostrea gigasand (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav inC. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts ofCgNav1named A, B and C, were characterized. The expression ofCgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed a strong expression ofCgNav1Ain the striated muscle whileCgNav1Bis mainly expressed in visceral ganglia.CgNav1Cexpression is ubiquitous. The PST binding site (domain II) ofCgNav1variants possess an amino acid Q that could potentially confer a partial saxitoxin (STX)-resistance to the channel. TheCgNav1genotype or alternative splicing would not be the key point determining PST bioaccumulation level in oysters.
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. floriane.boullot@gmail.com.
authors.forename: Floriane
authors.initials: F
authors.lastname: Boullot
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. justine.castrec@univ-brest.fr.
authors.forename: Justine
authors.initials: J
authors.lastname: Castrec
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. adeline.bidault@univ-brest.fr.
authors.forename: Adeline
authors.initials: A
authors.lastname: Bidault
authors.affiliation: Laboratory of Immunology and Pathology of Invertebrates, Department of Molecular Biology, Exact and Natural Sciences Center, Federal University of Paraíba-Campus I, 58051-900 João Pessoa, PB, Brazil. natan.cbio@gmail.com.
authors.forename: Natanael
authors.initials: N
authors.lastname: Dantas
authors.affiliation: UMR 5805 EPOC, CNRS-Équipe Écotoxicologie Aquatique, Université de Bordeaux, Station Marine d'Arcachon, 33120 Arcachon, France. l.payton@epoc.u-bordeaux1.fr.
authors.forename: Laura
authors.initials: L
authors.lastname: Payton
authors.affiliation: UMR 5805 EPOC, CNRS-Équipe Écotoxicologie Aquatique, Université de Bordeaux, Station Marine d'Arcachon, 33120 Arcachon, France. mickael.perrigault@u-bordeaux.fr.
authors.forename: Mickael
authors.initials: M
authors.lastname: Perrigault
authors.affiliation: UMR 5805 EPOC, CNRS-Équipe Écotoxicologie Aquatique, Université de Bordeaux, Station Marine d'Arcachon, 33120 Arcachon, France. d.tran@epoc.u-bordeaux1.fr.
authors.forename: Damien
authors.initials: D
authors.lastname: Tran
authors.affiliation: Laboratoire Phycotoxines, IFREMER, BP 21105, 44311 Nantes, France. zouher.amzil@ifremer.fr.
authors.forename: Zouher
authors.initials: Z
authors.lastname: Amzil
authors.affiliation: Ifremer, UMR 6539 LEMAR CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. pierre.boudry@ifremer.fr.
authors.forename: Pierre
authors.initials: P
authors.lastname: Boudry
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. philippe.soudant@univ-brest.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Soudant
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. helene.hegaret@univ-brest.fr.
authors.forename: Hélène
authors.initials: H
authors.lastname: Hégaret
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France. caroline.fabioux@univ-brest.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fabioux
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000235:genetics / Q000378:metabolism*; D004141:Dinoflagellida / Q000235:genetics / Q000378:metabolism; D008387:Marine Toxins / Q000378:metabolism*; D010125:Ostreidae / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012530:Saxitoxin / Q000378:metabolism; D012758:Shellfish; D061566:Voltage-Gated Sodium Channels / Q000378:metabolism*
chemical_list: D008387:Marine Toxins; D061566:Voltage-Gated Sodium Channels; D012530:Saxitoxin
keywords: Alexandrium minutum; Crassostrea gigas; alternative splicing; paralytic shellfish toxins; sodium channel