Peridinin-chlorophyll a proteins from the symbiotic dinoflagellate Symbiodinium (= Gymnodinium) microadriaticum, Freudenthal

various strains of the symbiotic dinoflagellate Symbiodinium (= Gymnodinium) microadriaticumn and analysed by isoelectric focusing in polyacrylamide gels, exhibited different patterns. In most instances the same pattern of conformers was found in each strain when freshly isolated from their respective hosts, after culture, and in two instances also after cloning. These observations suggest that characteristic patterns of PCP are diagnostic of particular strains of S. microadriaticum. Evidence is presented that generally the patterns do not change with environment. Analysis of PCP could potentially serve as a tool for the identification of strains of S. microadriaticum and could also serve as a marker for the empirical analysis of sexual recombination.