Chen, F. University of Georgia, fchen2@arches.uga.edu
Lu, J. University of Georgia, lu@arches.uga.edu
Hodson, R. E. University of Georgia, rhodson@arches.uga.edu

 
RuBisCO GENES REVEAL A CLOSE RELATIONSHIP BETWEEN SYNECHOCOCCUS STRAINS WH7803 AND WH8101
 
Synechococcus spp. are a diverse group which includes at least six clusters or genera (Waterbury and Rippka, 1989). Synechococcus isolates in marine cluster A utilize phycoerythrin as their primary light-harvesting pigment, while those in marine cluster B lack phycoerythrin. It will be interesting to know whether DNA sequences based on Calvin cycle enzyme ribulose-1,5,-bisphosphate carboxylase/oxygenase (RuBisCO) of Synechococcus in these two clusters also support this classification. A set of primers was designed and used to amplify the rbcL gene from marine Synechococcus strain WH8101 (cluster B), which produced a 700 bp PCR product. Nucleotide sequence of this rbcL shared the highest sequence identity (92.1%) with that of Synechococcus strain WH7803 among all rbcL genes available in GenBank. Moreover, the deduced amino acid sequences of the rbcL from strains WH7803 and WH8101 are more similar to homologues among the beta/gamma purple bacteria than to existing cyanobacterial ones, suggesting that both strains might have acquired their RuBisCO genes from a purple bacterium, and that strain WH8101 (cluster B) is closely related to strain WH7803 (cluster A) although their pigment phenotypes are different. Thus, evolution of different pigment phenotypes between the two Synechococcus strains may be a fairly modern event.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS40TU0536S