Virology Journal

official impact factor 2.55

Open Access Research

Marine mimivirus relatives are probably large algal viruses

Adam Monier1, Jens B Larsen2, Ruth-Anne Sandaa2, Gunnar Bratbak2, Jean-Michel Claverie1 and Hiroyuki Ogata1*

Author Affiliations

1 Structural and Genomic Information Laboratory, CNRS-UPR 2589, IBSM, Parc Scientifique de Luminy, 163 avenue de Luminy, Case 934, 13288 Marseille Cedex 9, France

2 Department of Biology, University of Bergen, PO Box 7800, N-5020 Bergen, Norway

For all author emails, please log on.

Virology Journal 2008, 5:12 doi:10.1186/1743-422X-5-12

Published: 23 January 2008

Abstract

Background

Acanthamoeba polyphaga mimivirus is the largest known ds-DNA virus and its 1.2 Mb-genome sequence has revealed many unique features. Mimivirus occupies an independent lineage among eukaryotic viruses and its known hosts include only species from the Acanthamoeba genus. The existence of mimivirus relatives was first suggested by the analysis of the Sargasso Sea metagenomic data.

Results

We now further demonstrate the presence of numerous "mimivirus-like" sequences using a larger marine metagenomic data set. We also show that the DNA polymerase sequences from three algal viruses (CeV01, PpV01, PoV01) infecting different marine algal species (Chrysochromulina ericina, Phaeocystis pouchetii, Pyramimonas orientalis) are very closely related to their homolog in mimivirus.

Conclusion

Our results suggest that the numerous mimivirus-related sequences identified in marine environments are likely to originate from diverse large DNA viruses infecting phytoplankton. Micro-algae thus constitute a new category of potential hosts in which to look for new species of Mimiviridae.