title: Contribution to the understanding of the cycle of the protozoan parasite Marteilia refringens.
abstract: The paramyxean parasite Marteilia refringens infects several bivalve species including European flat oysters Ostrea edulis and Mediterranean mussels Mytilus galloprovincialis. Sequence polymorphism allowed definition of three parasite types 'M', 'O' and 'C' preferably detected in oysters, mussels and cockles respectively. Transmission of the infection from infected bivalves to copepods Paracartia grani could be experimentally achieved but assays from copepods to bivalves failed. In order to contribute to the elucidation of the M. refringens life cycle, the dynamics of the infection was investigated in O. edulis, M. galloprovincialis and zooplankton over one year in Diana lagoon, Corsica (France). Flat oysters appeared non-infected while mussels were infected part of the year, showing highest prevalence in summertime. The parasite was detected by PCR in zooplankton particularly after the peak of prevalence in mussels. Several zooplanktonic groups including copepods, Cladocera, Appendicularia, Chaetognatha and Polychaeta appeared PCR positive. However, only the copepod species Paracartia latisetosa showed positive signal by in situ hybridization. Small parasite cells were observed in gonadal tissues of female copepods demonstrating for the first time that a copepod species other than P. grani can be infected with M. refringens. Molecular characterization of the parasite infecting mussels and zooplankton allowed the distinguishing of three Marteilia types in the lagoon.
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: I
authors.initials: I
authors.lastname: Arzul
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: B
authors.initials: B
authors.lastname: Chollet
authors.affiliation: Laboratoire EcoSym, UMR5119, Université Montpellier 2, CC 093, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
authors.forename: S
authors.initials: S
authors.lastname: Boyer
authors.affiliation: Laboratoire EcoSym, UMR5119, Université Montpellier 2, CC 093, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
authors.forename: D
authors.initials: D
authors.lastname: Bonnet
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: J
authors.initials: J
authors.lastname: Gaillard
authors.affiliation: IFREMER Laboratory Environment and Resource Provence Azur Corse, 20600 Bastia, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Baldi
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: M
authors.initials: M
authors.lastname: Robert
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Joly
authors.affiliation: IFREMER SG2M-LGPMM, Laboratory of Genetics and Pathology of Marine Molluscs, 17390 La Tremblade, France.
authors.forename: C
authors.initials: C
authors.lastname: Garcia
authors.affiliation: IFREMER Laboratory Environment and Resource Provence Azur Corse, 83507 La Seyne/Mer Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Bouchoucha
mesh_terms: D000818:Animals; D001483:Base Sequence; D056907:Cercozoa / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D033342:Copepoda / Q000469:parasitology*; D005260:Female; D005602:France; D041981:Gastrointestinal Tract / Q000469:parasitology; D006066:Gonads / Q000469:parasitology; D006651:Histocytochemistry; D006790:Host-Parasite Interactions; D017403:In Situ Hybridization; D008018:Life Cycle Stages; D008969:Molecular Sequence Data; D049878:Mytilus / Q000469:parasitology*; D049895:Ostrea / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D054712:Salinity; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013696:Temperature; D015048:Zooplankton / Q000469:parasitology*