You are here:
STEROLS AS BIOMARKERS IN GYMNODINIUM BREVE DISTRIBUTION IN DINOFLAGELLATES
Citation:
Chapman, P J. AND J D. Leblond. STEROLS AS BIOMARKERS IN GYMNODINIUM BREVE DISTRIBUTION IN DINOFLAGELLATES. 54th Annual Meeting of the Phycological Society of America, San Diego, CA, 16-19 July, 2000.
Description:
The sterol composition of marine microalgae has been shown to be a chemotaxonomic property potentially of value in distinguishing members of different algal classes. For example, members of the class Dinophyceae display sterol compositions ranging from as few as two (cholesterol and dinosterol in Alexandrium tamarense) to as many as twelve in certain Heterocapsa species. Certain of these are 4-methyl sterols rarely found in other classes of algae. The ability to use sterol biomarkers to distinguish certain dinoflagellates such as the toxic species Gymnodinium breve, responsible for red tide events in the Gulf of Mexico, from other species within the same class would be of considerable scientific and economic value. G. Breve has been shown by others to possess two principal novel sterols, (24S)-4a-methylergosta-8(14),22-dien-3b-ol (ED) and its 27-nor derivative (NED), not previously known to be present in other dinoflagellates. Characterization of free and esterified sterols from laboratory cultures of G. breve and of samples from a recent bloom in the Gulf of Mexico has confirmed the predominance of these two sterols. This has prompted a study of the sterol signatures of more than 30 dinoflagellates. ED and NED were shown also to be the primary sterols of the closely related dinoflagellates G. mikimotoi and G. galatheanum. They are also found as minor components of the more complex sterol profiles of other members of the Gymnodinium/Peridinium/Prorocentrum (GPP) taxonomic group. The more widespread distribution of this sterol pattern is consistent with the known close relationship between G. breve and G. mikimotoi.