Schaefer, M. C. Romberg Tiburon Centers, mschaefr@sfsu.edu
Wilkerson, F. C. Romberg Tiburon Centers, fwilkers@sfsu.edu
Hogue, V. Romberg Tiburon Centers, vhogue@sfsu.edu

 
DEVELOPMENT OF MOLECULAR PROBES FOR FUNCTIONAL GENES OF GLUTAMINE SYNTHETASE IN MARINE PHYTOPLANKTON
 
Most studies of the marine nitrogen cycle measure nitrogen uptake in situ and are unable to ascertain which components of the community are active in removing nitrate or ammonium. Applying functional gene probes for N assimilation enzymes in combination with in situ measurements offers a way to identify the active organisms. As part of a project to explore the use of molecular probes for detecting genetic capability for nitrogen transformations in Monterey Bay, CA, we have been developing functional gene probes for the ammonium assimilation enzyme glutamine synthetase (GS). Our target organisms include the diatoms Skeletonema costatum, Thalassiosira pseudonana and Chaetoceros debilis and the chlorophyte Dunaliella tertiolecta. It is likely that these algae have both GS II (45 kD)and GS III (70 kD polypeptide) (Robertson and Alberte, 1996). The GS II genes have been isolated previously in eukaryotes (including S. costatum) whereas GS III has only been isolated at the gene level from a couple of prokaryotes. We have designed degenerate GS II and GS III primers and tested them against cDNA from RNA extracted from our target organisms to give PCR products which have been cloned and are being sequenced. Preliminary results will be presented.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS41TU0860S