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. 2013 Dec;158(12):2517-21.
doi: 10.1007/s00705-013-1768-6. Epub 2013 Jun 29.

"Megavirales", a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses

Philippe Colson  1 , Xavier De Lamballerie, Natalya Yutin, Sassan Asgari, Yves Bigot, Dennis K Bideshi, Xiao-Wen Cheng, Brian A Federici, James L Van Etten, Eugene V Koonin, Bernard La Scola, Didier Raoult
Affiliations

"Megavirales", a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses

Philippe Colson et al. Arch Virol. 2013 Dec.

Abstract

The nucleocytoplasmic large DNA viruses (NCLDVs) comprise a monophyletic group of viruses that infect animals and diverse unicellular eukaryotes. The NCLDV group includes the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Mimiviridae and the proposed family "Marseilleviridae". The family Mimiviridae includes the largest known viruses, with genomes in excess of one megabase, whereas the genome size in the other NCLDV families varies from 100 to 400 kilobase pairs. Most of the NCLDVs replicate in the cytoplasm of infected cells, within so-called virus factories. The NCLDVs share a common ancient origin, as demonstrated by evolutionary reconstructions that trace approximately 50 genes encoding key proteins involved in viral replication and virion formation to the last common ancestor of all these viruses. Taken together, these characteristics lead us to propose assigning an official taxonomic rank to the NCLDVs as the order "Megavirales", in reference to the large size of the virions and genomes of these viruses.

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Figures

Fig. 1
Fig. 1
Coevolution of the viruses in the proposed order “Megavirales” and their hosts. The schematic family-level evolutionary tree of the NCLDVs represents the consensus of the phylogenies of the core NCLDV genes (superfamily II helicase (NCVOG0076), A2L-like transcription factor (NCVOG0262), RNA polymerase a subunit (NCVOG0274), RNA polymerase β subunit (NCVOG0271), mRNA capping enzyme, A32-like packaging ATPase (NCVOG0249), small subunit of ribonucleotide reductase (NCVOG0276), myristoylated envelope protein (NCVOG0211), primase-helicase (NCVOG0023), and DNA polymerase (NCVOG0038)). For the highly diverse family Phycodnaviridae, a more detailed, genus-level phylogeny is shown. The schematic supergroup-level evolutionary tree of the eukaryotes shows a multifurcation, given the lack of resolution at the deepest level. Lines connect virus families (and genera of the family Phycodnaviridae) and their known hosts
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References

    1. Iyer LM, Aravind L, Koonin EV. Common origin of four diverse families of large eukaryotic DNA viruses. J Virol. 2001;75:11720–11734. doi:10.1128/JVI.75.23.11720-11734.2001. - PMC - PubMed
    1. Iyer LM, Balaji S, Koonin EV, Aravind L. Evolutionary genomics of nucleo-cytoplasmic large DNA viruses. Virus Res. 2006;117:156–184. doi:10.1016/j.virusres.2006.01.009. - PubMed
    1. Yutin N, Wolf YI, Raoult D, Koonin EV. Eukaryotic large nucleo-cytoplasmic DNA viruses: clusters of orthologous genes and reconstruction of viral genome evolution. Virol J. 2009;6:223. doi:10.1186/1743-422X-6-223. - PMC - PubMed
    1. Raoult D, Audic S, Robert C, Abergel C, Renesto P, Ogata H, La Scola B, Suzan M, Claverie JM. The 1.2-megabase genome sequence of Mimivirus. Science. 2004;306:1344–1350. doi:10.1126/science.1101485. - PubMed
    1. Claverie JM, Abergel C, Ogata H. Mimivirus. Curr Top Microbiol Immunol. 2009;328:89–121. - PubMed

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