''Metaviridae'' is a family of
virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...
es which exist as Ty3-gypsy
LTR retrotransposons in a
eukaryotic
The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...
host's genome. They are closely related to
retroviruses: members of the family ''Metaviridae'' share many genomic elements with retroviruses, including length, organization, and genes themselves. This includes genes that encode
reverse transcriptase,
integrase, and
capsid proteins. The reverse transcriptase and integrase proteins are needed for the retrotransposon activity of the virus. In some cases, virus-like particles can be formed from capsid proteins.
Some assembled virus-like particles of members of the family ''Metaviridae'' can penetrate and infect previously uninfected cells. An example of this is the gypsy, a retroelement found in the ''
Drosophila melanogaster
''Drosophila melanogaster'' is a species of fly (an insect of the Order (biology), order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly", "pomace fly" ...
'' genome. The ability to infect other cells is determined by the presence of the retroviral ''env'' genes which encode coat proteins.
Metaviridae retrotransposons are found in all eukaryotes known and studied. Among the members are only species that produce intracellular particles, the collection of these particles is heterogeneous. Extracellular particles are surrounded by oval nuclei and are called virions. Genomes of retrotransposons in this family are positive strand RNAs. In addition to the RNA genome, some cellular RNAs can be randomly associated with particles, including specific tRNAs, in case of virus replication prepared by tRNAs. When it comes to virion producing members, it appears that the virion membrane is derived from the membrane of the host cell.
Taxonomy
The family ''Metaviridae'' is split into the following genera:
* Genus ''
Metavirus''
* Genus ''
Errantivirus''
Families ''Metaviridae'', ''
Belpaoviridae'', ''
Pseudoviridae'', ''
Retroviridae'', and ''
Caulimoviridae'' constitute the order ''
Ortervirales
''Ortervirales'' is an order that contains all accepted species of single-stranded RNA viruses that replicate through a DNA intermediate (Group VI) and all accepted species of double-stranded DNA viruses (except ''Hepadnaviridae'') that replicate ...
''.
References
External links
ICTV Report: ''Metaviridae''*
Descriptions of Plant Viruses
Ortervirales
RNA reverse-transcribing viruses
Virus families
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