Name: Rebekah Helton

Email: rrhelton@udel.edu

Author: R. R. Helton 1, S. W. Polson 1, D. M. Winget 2, L. Zeigler 3, D. W. Fadrosh 3, S. C. Cary 4, S. J. Williamson 3, K. E. Wommack 1

Author affiliation: 1 University of Delaware, Newark, DE, 2 University of British Columbia, Vancouver, BC, CANADA, 3 J. Craig Venter Inst., San Diego, CA, 4 University of Waikato, Hamilton, NEW ZEALAND

Abstract title: Exploration and induction of temperate phage from hydrothermal vent diffuse ?ow water

Absstract:

Deep-sea hydrothermal vent ecosystems are among the few unique environments where microbial chemolithotrophy is the dominant means of developing and driving energy flow within macro-faunal communities. Viruses, especially temperate viruses, commonly recognized as the most abundant members of marine microbial communities, are only now being recognized as substantial players in these extreme environments. Here, we investigated three hydrothermal vent locations: two separate sites at 9°N, 104°W, East Pacifc Rise (EPR) and one site at the Guaymas Basin in the Sea of Cortez, Mexico. The two separate EPR vent sites, located more than two kilometers apart, showed similar and statistically significant increases in viral abundances when treated with the prophage inducing agent, mitomycin-C. After twenty-four hours, mean viral abundance in mitomycin-C treated samples was 61% greater than untreated controls. However, diffuse-flow vent waters from the Guaymas Basin did not show significant levels of prophage induction, highlighting another potential difference in the microbial ecology of these two vent sites. Recent collections of diffuse flow vent waters from these sites, will allow the establishment of a detailed comparison base for temperate phages in hydrothermal vent ecosystems and allow further assessment of biogeographical variability. Preliminary epifluorescence microscopy suggests comparable trends exist within these newly collected vent samples, with increases in viral abundance upon induction. These data support the hypothesis that temperate viruses play especially significant roles in the extreme geothermal environments of the deep sea.