Evidence for chemoautotrophic symbiosis in a Mediterranean cold seep clam (Bivalvia : Lucinidae): comparative sequence analysis of bacterial 16S rRNA, APS reductase and RubisCO genes
|Author(s)||Duperron Sebastien1, 2, 3, Fiala Medioni Aline4, Caprais Jean-Claude2, Olu Karine2, Sibuet Myriam2|
|Affiliation(s)||1 : Univ Paris 06, UMR 7138, F-75005 Paris, France.
2 : IFREMER, Ctr Brest, Lab Environm Profond, F-29280 Plouzane, France.
3 : Max Planck Inst Marine Microbiol, Bremen, Germany.
4 : Univ Paris 06, Observ Oceanol, Banyuls sur Mer, France.
|Source||FEMS Microbiology Ecology (0168-6496) (Blackwell science), 2007 , Vol. 59 , N. 1 , P. 64-70|
|WOS© Times Cited||56|
|Keyword(s)||Eastern Mediterranean, Cold seeps, Lucinoma, Lucinidae, Sulphide oxidizing bacteria, Symbiosis|
|Abstract||Symbioses between lucinid clams (Bivalvia: Lucinidae) and autotrophic sulphide-oxidizing bacteria have mainly been studied in shallow coastal species, and information regarding deep-sea species is scarce. Here we study the symbiosis of a clam, resembling Lucinoma kazani, which was recently collected in sediment cores from new cold-seep sites in the vicinity of the Nile deep-sea fan, eastern Mediterranean, at depths ranging from 507 to 1691 m. A dominant bacterial phylotype, related to the sulphide-oxidizing symbiont of Lucinoma aequizonata, was identified in gill tissue by comparative 16S rRNA gene sequence analysis. A second phylotype, related to spirochete sequences, was identified twice in a library of 94 clones. Comparative analyses of gene sequences encoding the APS reductase alpha subunit and ribulose-1,5-bisphosphate carboxylase oxygenase support the hypothesis that the dominant symbiont can perform sulphide oxidation and autotrophy. Transmission electron micrographs of gills confirmed the dominance of sulphide-oxidizing bacteria, which display typical vacuoles, and delta C-13 values measured in gill and foot tissue further support the hypothesis for a chemoautotrophic-sourced host carbon nutrition.|