Aquatic Sciences Meeting, Albuquerque 2001

SS04 Environmental Microbial Genomics (Environmental and Disciplinary Connections)

Date: Wednesday, February 14, 2001, Time: 12:00:00 PM

Location: Brazos

Gast, R, J, Woods Hole Oceanographic Institution, Woods Hole, USA, rgast@whoi.edu

Beaudoin, D, , Marine Biological Laboratory, Woods Hole, USA,

Dennett, M, R, Woods Hole Oceanographic Institution, Woods Hole, USA,

Moran, D, M, Woods Hole Oceanographic Institution, Woods Hole, USA,

Caron, D, A, University of Southern California, Los Angeles, USA,

GENETIC DIVERSITY OF PROTISTS IN ANTARCTIC MARINE ENVIRONMENTS

Seasonal pack ice surrounding the Ross Sea, Antarctica, has been shown to harbor a rich and varied community of microalgae and protozoa. Traditional microscopical approaches have produced lengthy species lists, but are not readily amenable to ecological studies. In developing new approaches, we have been examining protistan assemblages associated with water, ice and slush (infiltration or freeboard layer) microhabitats using denaturing gradient gel electrophoresis. These studies indicated that patterns obtained from similar sample types (e.g. water) were more similar to each other, even at different locations within the Ross Sea. Additionally, a significant fraction of the bands observed using DGGE were distinct within each sample, indicating potentially large genetic diversity. The latter observation is consistent with direct microscopical observations and published reports. To further assess genetic diversity, srRNA gene libraries were generated and partially sequenced for a single station. More than half the clones from slush and water libraries were of a dinoflagellate closely related to Pentapharsodinium, but otherwise, there was little overlap in sequence types between different samples. These findings imply that microhabitat structure strongly influences protistan species composition.

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Aquatic Sciences Meeting, Albuquerque 2001

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