Karenia brevis (Davis) Hanson and Moestrup is a unicellular dinoflagellate protist that causes harmful algal blooms that occur annually in the Gulf of Mexico. These “red tides” cause extensive marine animal mortalities and human illness through the production of highly potent neurotoxins known as brevetoxins. Insight into the molecular mechanisms that control the growth and persistence of K. brevis blooms is critical to understanding the formation of harmful algal blooms and is a prerequisite for the development of control strategies. Karenia species (and other fucoxanthin-containing dinoflagellates) also occupy a critical position among algae with regard to plastid (photosynthetic organelle) evolution. These taxa have undergone a remarkable genomic transition from an ancestral condition in which their plastid genome comprised a small number of (ca. 16) single-gene minicircles (the remaining plastid genes being nuclear-encoded) to having reverted to a putatively typical plastid through tertiary endosymbiosis (where one organism engulfs a symbiotic organism that has already engulfed another organism, which has in turn engulfed yet another organism). Draft sequences will also be generated for the plastid and mitochondrial genomes of K. brevis and its sister Karlodinium micrum to gain insights into plastid endosymbiosis and organellar gene transfer.
CSP project participants: Debashish Bhattacharya (proposer, Univ. of Iowa) and Frances Van Dolah (Natl. Oceanic and Atmospheric Admin.)