Meeting Abstract

P2.50  Sunday, Jan. 5 15:30  Isolation and Characterization of Cyanobacterial Symbionts Associated with Oceanic Clonal Sea Star Larvae JERABEK, A/S; PIEDMONTE, N/P*; BOSCH, I; SUNY Geneseo; SUNY Geneseo; SUNY Geneseo bosch@geneseo.edu

Clonal sea star larvae that are abundant in oligotrophic open ocean waters of the North Atlantic carry an extensive subcuticular bacterial flora. Results of 16s-rDNA sequence analysis reported elsewhere indicate that the dominant microbes are cyanobacteria. We conducted analyses of pigment fluorescence and the RNA polymerase C complex gene (rpoC1) sequence to more specifically identify the isolated strains. Clonal larvae were collected from the Gulf Stream and washed four times in filter sterilized water. Samples of intact and crushed larvae were incubated for several days in Guillard’s F/2 algal growth medium. After two weeks cyanobacterial cells were evident in cultures. Analysis of absorption and emission by spectrofluorometry indicated that the most abundant accessory pigment in some isolates was phycoerythrin (peak ABS at 540 nm and fluorescence at 561 nm ) while others contained primarily phycocyanin (ABS at 620 nm and fluorescence at 650 nm). DNA from one isolate culture was extracted and amplified by PCR using (rpoC1) complex gene. The amplification products were purified through an electrophoresis gel extraction and cloned with E. coli. Sequencing results indicated that one isolate was closely related to Synechococcus sp. WH8102, a motile strain of Synechococcus isolated from the Sargasso Sea. Experiments aiming to colonize newly released aposymbiotic clonal larvae with Synechococcus isolates are currently underway.