Immunochemical characterization of morphospecies and strains of Prorocentrum (dinophyceae)

Antibodies were developed against cell surface antigens of Prorocentrum lim a (Ehrenberg) Dodge, P. triestinum, P. micans Ehrenberg, P. minimum (Pavill ard) Schiller and P. rostratum Stein. Positive antigenic reactions were vis ualized with epifluorescence microscopy, using a fluorescein isothiocyanate (FITC) indirect immunofluorescence assay. An immunoassay with a secondary magnetic bead-conjugated antibody was also used. Polyclonal antisera agains t P. lima and against P. rostratum were species-specific. In contrast, the other antisera showed weak cross-reactions. The antisera with insufficient specificity were improved by exposure to cross-reacting antigens. Thus, spe cies-specific preadsorbed antisera were obtained against each species. A se t of strain-specific antibodies against P. lima clones were also prepared b y preadsorption. The immunomagnetic bead assay also allowed us to separate P, lima cells from sediment surface samples or macroalgae. Antibody binding patterns were used to establish phenetic relationships among species/clone s examined. P. micans, P. triestinum and P. minimum appeared as closely rel ated. In contrast, P. lima, and P. rostratum emerged distant from the other Prorocentrum species. Additionally, serological differences between natura l populations of P. lima (a DSP toxin-producing benthic dinoflagellate) wer e detected. (C) 1999 Elsevier Science B.V. All rights reserved.