SS2.03 Phytoplankton Ecology Using Molecular Approach
Date: Thursday, June 13, 2002
Time: 3:15:00 PM
Location: Colwood
 
Van DolahFM, NOAA National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC 29412, USA, fran.vandolah@noaa.gov
Barbier, M, , NOAA NOS CCEHBR, Charleston, SC, USA, 
Leighfield, T, A, NOAA NOS CCEHBR, Charleston, SC, USA, 
Tyler, J, S, NOAA NOS CCEHBR, Charleston, SC, USA, 
 
GROWTH REGULATION IN THE FLORIDA RED TIDE DINOFLAGELLATE, KARENIA BREVIS: A GENOMIC APPROACH
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K. brevis blooms almost annually off the west coast of Florida, where its neurotoxins impact human and ecosystem health. Despite a sluggish growth rate of 0.2-0.5 div./day, it achieves dense monospecific blooms that may cover many square km and persist for months before terminating. We were therefore interested in the dynamics of cell division during K. brevis blooms, the mechanisms regulating it, and identification of a biomarker for growing versus terminating blooms. K. brevis expresses eukaryotic cell cycle regulators, cyclin and cyclin-dependent kinase. CyclinB is usually regulated at the transcriptional level; however, cyclinB in K. brevis is constitutively expressed during the cell cycle. This is of interest since its cell cycle is under circadian control, and many circadian-controlled dinoflagellate genes are regulated translationally or post-translationally. mRNA differential display yielded few differentially expressed transcripts over two cell cycles (diel cycles), and no cell cycle regulators. Thus we have taken a genomic approach to identifying cell cycle regulators: cDNA library screening has yielded several cell cycle-associated genes typically regulated at the transcriptional level. Differential expression of these genes will be presented.