In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba

@article{Legendre2015IndepthSO,
  title={In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba},
  author={Matthieu Legendre and Audrey Lartigue and Lionel Bertaux and Sandra Jeudy and Julia Bartoli and Magali Lescot and Jean-Marie Alempic and Claire Ramus and Christophe Bruley and Karine Labadie and Lyubov Shmakova and Elizaveta M Rivkina and Yohann Cout{\'e} and Chantal Abergel and Jean-Michel Claverie},
  journal={Proceedings of the National Academy of Sciences},
  year={2015},
  volume={112},
  pages={E5327 - E5335}
}
Significance The saga of giant viruses (i.e. visible by light microscopy) started in 2003 with the discovery of Mimivirus. Two additional types of giant viruses infecting Acanthamoeba have been discovered since: the Pandoraviruses (2013) and Pithovirus sibericum (2014), the latter one revived from 30,000-y-old Siberian permafrost. We now describe Mollivirus sibericum, a fourth type of giant virus isolated from the same permafrost sample. These four types of giant virus exhibit different virion… 

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References

SHOWING 1-10 OF 56 REFERENCES
Pandoraviruses: Amoeba Viruses with Genomes Up to 2.5 Mb Reaching That of Parasitic Eukaryotes
TLDR
The isolation of two giant viruses, one off the coast of central Chile, the other from a freshwater pond near Melbourne, without morphological or genomic resemblance to any previously defined virus families are reported.
Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology
TLDR
A third type of giant virus combining the Pandoravirus morphology with a gene content more similar to that of icosahedral DNA viruses is isolated from a >30,000-y-old radiocarbon-dated sample of Siberian permafrost, suggesting that pandorav virus-like particles may correspond to an unexplored diversity of unconventional DNA virus families.
Giant Marseillevirus highlights the role of amoebae as a melting pot in emergence of chimeric microorganisms
TLDR
It is proposed that amoebae are “melting pots” of microbial evolution where diverse forms emerge, including giant viruses with complex gene repertoires of various origins.
Genome of Phaeocystis globosa virus PgV-16T highlights the common ancestry of the largest known DNA viruses infecting eukaryotes
TLDR
The presence of many genes found only in Megaviridae in its genome and the presence of an associated virophage strongly suggest that PgV-16T shares a common ancestry with the largest known dsDNA viruses, the host range of which already encompasses the earliest diverging branches of domain Eukarya.
Related Giant Viruses in Distant Locations and Different Habitats: Acanthamoeba polyphaga moumouvirus Represents a Third Lineage of the Mimiviridae That Is Close to the Megavirus Lineage
TLDR
The moumouvirus represents a third lineage beside mimivirus and megavirus, a new member of the recently proposed Megavirales order, and genomic comparisons of the Mimiviridae reveal significant mobility of Group I self-splicing introns, with the highest intron content observed in the mouMouv virus genome.
Distant Mimivirus relative with a larger genome highlights the fundamental features of Megaviridae
TLDR
Megavirus chilensis is presented, a giant virus isolated off the coast of Chile, but capable of replicating in fresh water acanthamoeba and exhibits three additional aminoacyl-tRNA synthetase genes adding strong support to the previous suggestion that the Mimivirus/Megav virus lineage evolved from an ancestral cellular genome by reductive evolution.
“Marseilleviridae”, a new family of giant viruses infecting amoebae
TLDR
Phylogenetic reconstructions showed that APMaV belongs to a new viral family among nucleocytoplasmic large DNA viruses, a group of viruses that also includes Acanthamoeba polyphaga mimivirus (APMV) and the other members of the family Mimiviridae as well as theMembers of the families Poxviridae, Phycodnaviridae, Iridovir Families, Ascovir families, and Asfarviridae.
Mimivirus and its virophage.
TLDR
The recent isolation of a new type of satellite virus, called a virophage, associated with a second strain of Mimivirus, confirmed its unique position within the virus world.
Genome Analysis of the First Marseilleviridae Representative from Australia Indicates that Most of Its Genes Contribute to Virus Fitness
TLDR
Genomic comparisons of Marseilleviridae demonstrate that most of their genes, irrespective of their functions and conservation across families, are evolving under negative selection, contrasting with the more common view that many of the genes of the usually more diverse large DNA viruses might be (almost) dispensable.
...
...