Marine mimivirus relatives are probably large algal viruses.
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.


CONCLUSIONS
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.
Monier
Adam
A
Structural and Genomic Information Laboratory, CNRS-UPR 2589, IBSM, Parc Scientifique de Luminy, 163 avenue de Luminy, Case 934, 13288 Marseille Cedex 9, France. adam.monier@igs.cnrs-mrs.fr
Larsen
Jens Borggaard
JB
Sandaa
Ruth-Anne
RA
Bratbak
Gunnar
G
Claverie
Jean-Michel
JM
Ogata
Hiroyuki
H
D000048:Acanthamoeba / Q000821:virology*; D000818:Animals; D004267:DNA Viruses / Q000145:classification* / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D008386:Marine Biology; D009792:Oceans and Seas; D016366:Open Reading Frames; D017862:Phycodnaviridae / Q000145:classification*; D010802:Phylogeny; D010839:Phytoplankton / Q000821:virology
D004259:DNA-Directed DNA Polymerase