SS2.03 Phytoplankton Ecology Using Molecular Approach
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
 
DennettMR, Woods Hole Oceanographic Institution, Woods Hole, USA, mdennett@whoi.edu
Gast, R, J, Woods Hole Oceanographic Institution, Woods Hole, USA, 
Countway, P, D, University of Southern California, Los Angeles, USA, 
Caron, D, A, University of Southern California, Los Angeles, USA, 
Moran, D, M, Woods Hole Oceanographic Institution, Woods Hole, USA, 
 
ANALYSIS OF CONTAINMENT EFFECTS ON THE DIVERSITY OF PROTISTAN ASSEMBLAGES FROM THE SARGASSO SEA AND SAN PEDRO CHANNEL BY DENATURING GRADIENT GEL ELECTROPHORESIS
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Long-term incubation of natural protistan communities is currently the primary means for determining community grazing rates by these assemblages. This approach requires the containment of water samples in bottles for 24-48 hours or longer, usually with the addition of nutrients. Changes in algal composition during bottle incubations can affect herbivore populations and grazing rates, potentially altering the measured rates of energy transfer and their relevance to the original sample. We conducted deck incubation experiments on water samples collected in the Sargasso Sea and in the San Pedro Channel to examine changes in protistan community structure as a result of bottle containment and amendment with organic and inorganic nutrients. DGGE analysis of PCR amplified 18S rDNA revealed shifts in community structure over time and also as a consequence of enrichment. RT-PCR-based DGGE analyses are currently being conducted to determine whether the DNA profiles represent the active organisms in the samples. Sequencing of DGGE bands have identified dinoflagellates, prasinophytes and other copepods, and 18S rDNA clone libraries are also being sequenced to obtain further information on the genetic variation in these samples.