Viral infection of bacteria and phytoplankton in the Arctic Ocean as viewed through the lens of fingerprint analysis

Abstract

Viruses are the most abundant biological entities in the oceans and play crucial roles as mortality agents and as catalysts in biogeochemical cycles. During a year-long study in the southeastern Beaufort Sea and Amundsen Gulf in the Canadian Arctic, we used denaturing gradient gel electrophoresis (DGGE) to investigate temporal and spatial changes in gene sequences encoding DNA polymerase B (polB) and the major capsid protein (g23) that are specific for the virus families Phycodnaviridae and Myoviridae, which infect phytoplankton and bacteria, respectively. Multivariate analysis indicated that the genetic composition of viruses infecting phytoplankton was related to changes in productivity and hydrological conditions, as well as with changes in the potential host community, as indicated by DGGE fingerprints of 18S rDNA. In contrast, changes in the composition of viruses infecting bacteria could not be related to changes in environmental variables or DGGE fingerprints of bacterial (16S) or eukaryotic (18S) rDNA. Overall, these results document persistent and highly dynamic T4-like viruses and phycodnaviruses on the Canadian Arctic Shelf, implying that they are important in shaping microbial communities in the Arctic Ocean. © Inter-Research 2014.