Exploration of the propagation of transpovirons within Mimiviridae reveals a unique example of commensalism in the viral world

@article{Jeudy2019ExplorationOT,
  title={Exploration of the propagation of transpovirons within Mimiviridae reveals a unique example of commensalism in the viral world},
  author={Sandra Jeudy and Lionel Bertaux and Jean-Marie Alempic and Audrey Lartigue and Matthieu Legendre and Lucid Belmudes and S{\'e}bastien Santini and Nad{\`e}ge Philippe and Laure Beucher and Emanuele G. Biondi and Sissel Juul and Daniel J. Turner and Yohann Cout{\'e} and Jean-Michel Claverie and Chantal Abergel},
  journal={The ISME Journal},
  year={2019},
  volume={14},
  pages={727 - 739}
}
Acanthamoeba -infecting Mimiviridae are giant viruses with dsDNA genome up to 1.5 Mb. They build viral factories in the host cytoplasm in which the nuclear-like virus-encoded functions take place. They are themselves the target of infections by 20-kb-dsDNA virophages, replicating in the giant virus factories and can also be found associated with 7-kb-DNA episomes, dubbed transpovirons. Here we isolated a virophage (Zamilon vitis) and two transpovirons respectively associated to B- and C-clade… 
The Discovery of a New Mimivirus Isolate in Association with Virophage-Transpoviron Elements in Brazil Highlights the Main Genomic and Evolutionary Features of This Tripartite System
TLDR
The main genomic features of mimivirus argentum and of its virophage/transpoviron elements corroborates with what is described for other known elements, highlighting that this triple genomic and biological interaction may be ancient and well-conserved.
Virophages and retrotransposons colonize the genomes of a heterotrophic flagellate
TLDR
It is shown that virophages are widespread and dynamic in wild Cafeteria populations, supporting their potential role in antiviral defense in protists and uncovered a unique association between EMALEs and a group of tyrosine recombinase retrotransposons, revealing yet another layer of parasitism in this nested microbial system.
Endogenous virophages populate the genomes of a marine heterotrophic flagellate
TLDR
The findings show that virophages are common, diverse, and dynamic genome components of the marine protist C. burkhardae, which implies important eco-evolutionary roles for these enigmatic viruses.
Viruses Defined by the Position of the Virosphere within the Replicator Space
TLDR
An operational definition of virus is presented that recently has been accepted by the International Committee on Taxonomy of Viruses and consists of a distinct variety of replicators that encode structural proteins encasing the replicators’ genomes, thereby providing protection and facilitating transmission among hosts.
Unique viruses that infect Archaea related to eukaryotes
TLDR
This first glimpse of Asgard viruses reveals they have features of both prokaryotic and eukaryotic viruses, and provides insights into their roles in the ecology and evolution of these globally distributed microbes.
The DNA methylation landscape of giant viruses
TLDR
It is shown that DNA methylation is widespread, affecting 2/3 of the tested families, although unevenly distributed, and evolutionary analysis of virus encoded DNA methyltransferases suggests that they affect viral fitness.
Giant Mimiviridae CsCl Purification Protocol.
TLDR
A protocol is reported for the purification of members of the Mimiviridae family virions resulting from Acanthamoeaba castellanii infections to optimize the isolation of the virus from the cell debris or other potential contaminants.
Shrinking of repeating unit length in leucine-rich repeats from double-stranded DNA viruses
TLDR
This study characterized viral LRRs by sequence analysis and identified over 600 LRR proteins from 89 virus species, finding that the repeating unit lengths of 11 types are one to five residues shorter than those of the seven known corresponding LRR classes.
Are Covid-19-positive mothers dangerous for their term and well newborn babies? Is there an answer?
TLDR
There is a hope that instruction on coping with the coronavirus (Covid-19) infection in pregnancy with all proposed interventions affecting mothers, babies and families, besides saving lives, are beneficial and efficient by exerting no harm.
...
...

References

SHOWING 1-10 OF 82 REFERENCES
Provirophages and transpovirons as the diverse mobilome of giant viruses
TLDR
The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer.
MIMIVIRE is a defence system in mimivirus that confers resistance to virophage
TLDR
It is found that lineage A strains are resistant to Zamilon and contain the insertion of a repeated Zamilon sequence within an operon, here named the ‘mimivirus virophage resistance element’ (MIMIVIRE).
Mimiviridae: An Expanding Family of Highly Diverse Large dsDNA Viruses Infecting a Wide Phylogenetic Range of Aquatic Eukaryotes
TLDR
The Mimiviridae family is described, its current taxonomic structure is described and a set of operational criteria to help in the classification of future isolates are proposed.
Zamilon, a Novel Virophage with Mimiviridae Host Specificity
TLDR
By co-culturing amoebae with purified Zamilon, it is found that the virophage is able to multiply with members of groups B and C of the Mimiviridae family but not with viruses from group A.
The kinetoplastid-infecting Bodo saltans virus (BsV), a window into the most abundant giant viruses in the sea
TLDR
The giant Bodo saltans virus (BsV), the first characterized representative of the most abundant giant viruses in the oceans, and the first klosneuvirus isolate, a subgroup of the Mimiviridae proposed from metagenomic data are presented.
The Expanding Family of Virophages
TLDR
Virophages replicate with giant viruses in the same eukaryotic cells, and could be commonly exposed to humans, although currently limited evidence exists of their presence in humans based on serology and metagenomics.
Broad Spectrum of Mimiviridae Virophage Allows Its Isolation Using a Mimivirus Reporter
TLDR
It is found that the first two strains of virophages isolated with group A Mimiviridae can multiply easily in groups B and C and play a role in gene transfer among these virus subgroups, suggesting that the spectrum of vIROphages is not limited to their initial host.
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.
Complete genome sequence of Courdo11 virus, a member of the family Mimiviridae
TLDR
The comparative analyses of Courdo11 virus with the genomes of other giant viruses showed that it belongs to lineage C of mimiviruses of amoebae, being most closely related to Megavirus chilensis and LBA 111, the first mimivirus isolated from a human.
The virophage as a unique parasite of the giant mimivirus
TLDR
The Sputnik genome is an 18.343-kilobase circular double-stranded DNA and contains genes that are linked to viruses infecting each of the three domains of life Eukarya, Archaea and Bacteria and is classified as a virophage.
...
...