12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006families.Without histones and with a lowproportion of histone-like proteins,dinoflagellates need a different wayof packing their huge amounts ofDNA into functional chromatin.Despite the interest in their genome,studies on the molecularorganization of their chromosomesare scarce.FISH with telomeric and rDNA genesequences were applied to threedinoflagellates species. Our resultsrevealed the clustering of rDNAgenes in NORs and the presence ofdistal telomeres, which confirms thelinear organization of theirchromosomes. They also showedspecific features such as thepresence of non-randomlydistributed structural RNA in thechromosome body. These resultsprovide the first evidence ofeukaryotic differentiation of theseunique chromosomes, reinforcingthe dinoflagellates’ position withinthe eukaryotic lineage.PO.05-05Lipophilic toxins in Frenchshellfish: first report ofpectenotoxin-2, spirolide-C andtheir isomers by liquidchromatography/massspectrometrySession: PO.05 - Toxin analysisZouher Amzil, Florence Royer,Manoella Sibat, Solene Guimard,Nadine Neaud-Masson, ClaudeChiantellaIFREMER, NANTES CEDEX 3, FranceDuring the French Phytoplanktonand Phycotoxins monitoring network(REPHY), shellfish samples wereharvested from different locationswhere harmful algae bloomoccurred. For all shellfish samplesfound positive for diarrheic shellfishpoisoning (DSP) toxins by mousebioassay, liquid chromatography(LC) coupled with massspectrometry (MS) was used tosearch for the following lipophilictoxins: okadaic acid (OA),dinophysistoxins (DTXs),pectenotoxins (PTXs), azaspiracids(AZAs), yessotoxins (YTXs),spirolides (SPXs) and gymnodimine(GYM). In order to investigate thepresence of okadaic acid esters,alkaline hydrolysis was performedon all samples, and LC/MSanalyses were carried out on thesamples before and after hydrolysis.The results revealed differentlipophilic toxin profiles depending onshellfish sampling locations. Theprimary finding was that all samplescontained okadaic acid and its acylesterderivatives (DTX-3). Inaddition, other lipophilic toxins werefound in the shellfish samples: DTX-2, its acyl ester derivatives (DTX-3)and spirolides (SPXs) on theAtlantic coast (Southern Brittany,Arcachon), pectenotoxins (PTX-2,PTX-2-Seco-acid) on theMediterranean coast (Thau Lagoon,Corsica Island). This paper is thefirst occurrence of pectenotoxin-2,spirolide-C-deMe and their isomersin France.PO.13-24Harmful algal blooms andeutrophication: nutrient sources,composition and consequencesin the Arabian Gulf borderingAbu Dhabi EmirateSession: PO.13 - Regional eventsRajan Anbiah, Thabit ZA AlAbdessalaamEnvironment Agency, ABU DHABI, UnitedArab EmiratesThe Arabian Gulf has witnessed anincrease in algal bloom incidentsover the last decade, presumably125