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 2006AD Cembella 1 , C Kantu 2 , B Krock 1 , NJaeckisch 1 , E Cañete 3 , A Caillaud 3 , JDiogène 3 , U Tilmann 1 , U John 11 Alfred Wegener Institute,BREMERHAVEN, Germany2 MPI for Marine Microbiology, BREMEN,Germany3 IRTA Centre d’Aquicultura, SANTCARLES DE LA RAPITA, SpainThe marine dinoflagellateAlexandrium ostenfeldii produces awide diversity of macrocyclic iminetoxins known as spirolides.Biosynthetic studies with stableisotope labeling and NMRspectroscopy support a commonpolyketide origin for spirolides. Wehave also identified several putativepolyketide synthases (PKS) inlimited genomic studies of A.ostenfeldii. Exposure to A.ostenfeldii cells elicits anallelochemical response in certainprotist species. To determinepharmacological activity ofspirolides and other bioactivesubstances produced by A.ostenfeldii, neuroblastoma (N2a)cell lines were exposed to crude cellextracts and pure des methyl Cspirolide. Cytotoxicity tests showedthat crude extracts caused largeblebbings within hours in a dosedependantmanner. Cells exposedto des methyl C spirolide inducedonly small blebbings, with no furtherchanges observed over longerexposure times (24 h).Transcriptional analysis with apathway targeted DNA microarrayyielded evidence of many more'down regulated' than 'up regulated'genes upon exposure to spirolidesand crude cell extracts, particularlygenes involved innecrosis/apoptosis/stress (e.g. 'heatshock proteins') andgrowth/senescence. Nevertheless,the differences observed inexpression patterns between desmethyl C spirolide and spirolidecontainingA. ostenfeldii extractssuggest that the toxic effects are notdue only to spirolides but also toother bioactive substances.O.10-01Successful production ofantibodies against azaspiracidsSession: O.10 - Toxin analysis 2Presentation time: 14:55 - 15:15IA Samdal 1 , LR Briggs 2 , CO Miles 2 , CJForsyth 3 , ST Nguyen 3 , J Xu 3 , TRundberget 1 , M Sandvik 11 National Veterinary Institute, OSLO,Norway2 AgResearch, HAMILTON, New Zealand3 University of Minnesota, MINNESOTA,United States of AmericaAzaspiracids have recurredregularly in Northern Europeanshellfish since their discovery inNovember 1995 in Irish mussels.Their presence in shellfish poses arisk of acute nausea, vomiting andsevere diarrhoea in humanconsumers and chronic effects aresuspected. There is an urgent needfor sensitive, simple, rapid,affordable methods with a highsample throughput. Here we reportthe first production of antibodiesagainst azaspiracids.A synthetic hapten representing thecommon C-28–C-40 domain of allthe known azaspiracids wassynthesised in Minnesota,conjugated to a carrier protein, andused to immunise sheep forantibody production in both Norwayand New Zealand. Preliminaryresults indicate that the resultingantibodies recognise a range ofazaspiracids. The antibodies havebeen utilised to develop an ELISAfor azaspiracids and immunoaffinitycolumns. Further optimisation of theapplication of the antibodies inimmunoassays is under way.50