SS2.03 Phytoplankton Ecology Using Molecular Approach
Date: Thursday, June 13, 2002
Time: 4:00:00 PM
Location: Colwood
 
GastRJ, Woods Hole Oceanographic Institution, Woods Hole, USA, rgast@whoi.edu
Beaudoin, D, J, Marine Biological Laboratory, Woods Hole, USA, beaudoin@evol5.mbl.edu
 
ISOLATION AND CHARACTERIZATION OF GENES POTENTIALLY INVOLVED IN PHOTOSYMBIOTIC ASSOCIATIONS
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We are studying the genetic communication involved in photosymbiotic associations to determine what makes an alga an acceptable symbiont, and to identify algal genes expressed in common between divergent associations. Planktonic foraminifera and radiolaria are ameboid protists that occur in the pelagic environment of the World's oceans. Host species in this group harbor a taxonomically diverse collection of algal symbionts. We initiated this project with the comparison of mRNA expressed in symbiotic and free-living dinoflagellate symbionts from the radiolarian Thalassicolla nucleata. The two RNA samples were analyzed by suppression subtractive hybridization, and currently 15 prospective differentially expressed clones have been isolated. Sequence analysis has indicated that 11 were identical, with the remaining four clones being unique. Blast analyses show that the F7 clone is a series of repeats with strong homology to repeats found in the Cyplasin S protein. The other clones were not significantly similar to any nucleotide or protein sequences in the databases. We are currently working towards confirming differential expression through RT-PCR and dot blot hybridization analyses, and recovering full-length cDNAs and genomic sequences for each clone.