''Betatorquevirus'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of
virus
A virus is a wikt:submicroscopic, 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 ...
es in the family ''
Anelloviridae
''Anelloviridae'' is a family of viruses. They are classified as vertebrate viruses and have a non-enveloped capsid, which is round with isometric, icosahedral symmetry and has a triangulation number of 3.
The name is derived from Italian ''anel ...
'', in group
II in the Baltimore classification. The genus ''Betatorquevirus'' includes all "torque teno mini viruses" (TTMV), numbered from 1 to 38 as 38 species.
Taxonomy
The genus contains the following species:
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Torque teno mini virus 1''
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Torque teno mini virus 2''
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Torque teno mini virus 3''
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Torque teno mini virus 4''
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Torque teno mini virus 5''
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Torque teno mini virus 6''
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Torque teno mini virus 7''
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Torque teno mini virus 8''
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Torque teno mini virus 9''
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Torque teno mini virus 10''
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Torque teno mini virus 11''
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Torque teno mini virus 12''
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Torque teno mini virus 13''
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Torque teno mini virus 14''
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Torque teno mini virus 15''
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Torque teno mini virus 16''
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Torque teno mini virus 17''
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Torque teno mini virus 18''
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Torque teno mini virus 19
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
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Torque teno mini virus 20
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
''
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Torque teno mini virus 21
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
''
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Torque teno mini virus 22
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
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Torque teno mini virus 23
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
''
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Torque teno mini virus 24
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
''
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Torque teno mini virus 25
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
''
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Torque teno mini virus 26
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of the ...
''
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Torque teno mini virus 27
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of the ...
''
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Torque teno mini virus 28''
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Torque teno mini virus 29''
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Torque teno mini virus 30''
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Torque teno mini virus 31''
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Torque teno mini virus 32''
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Torque teno mini virus 33''
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Torque teno mini virus 34''
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Torque teno mini virus 35''
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Torque teno mini virus 36''
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Torque teno mini virus 37''
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Torque teno mini virus 38''
Initial discovery
The discovery of TTMV, like the original
Torque Teno virus
''Alphatorquevirus'' is a genus of viruses in the family ''Anelloviridae'', in group II in the Baltimore classification. It encompasses many species of the virus formerly known as TTV, transfusion transmitted virus, or torque teno virus, SENV, S ...
(TTV) isolate, was accidental. After TTV was isolated in 1997 from a Japanese patient, primers were created to study TTV in more detail. TTV-specific primers used in PCR of human plasma samples yielded sequences that partially matched that of TTV, but were noticeably shorter.
TTV was eventually understood to have a genome of 3.6–3.9 kb, while TTMV has a genome of 2.8–2.9 kb. Another TT-like virus later isolated in 2007,
Torque teno midi virus
''Gammatorquevirus'' is a genus of viruses in the family ''Anelloviridae'', in group DNA virus#Group II: ssDNA viruses, II in the Baltimore classification. It contains 15 species. The fifteen species are all named "torque teno midi virus" (TTMDV) ...
or TTMDV, has a genome of 3.2 kb.
Genome and capsid
TTMV shares similar morphologic features with the other human anelloviruses. The capsid has a T=1 icosahedral symmetry.
The virion does not have a lipid envelope and is thus "naked", making it an extremely simple virus. It is estimated that the virion is a little less than 30 nm in diameter.
The genome is circular and made of single-stranded DNA of negative polarity. It is 2.86–2.91 kilobases long.
Anelloviruses are known for having 3 or 4 overlapping, nested open reading frames; TTMV has 3 ORF's that overlap.
ORF-2 and ORF-3 overlap with ORF-1 at opposite ends. For TTMV, ORF-1 is about 663 residues and ORF-2 is about 91 residues long.
There is a highly conserved 130-nt region just downstream of the TATA box.
Phylogeny & spread
TTMV is highly divergent.
The first phylogenetic tree created from TTMV genomic sequences revealed a large cluster of strains; ORF-1 had divergences of over 42% at the nucleotide level and over 67% at the amino acid level.
TTMV is also highly prevalent, like other human anelloviruses. Subsequent research after it was discovered has yielded the prevalence of TTMV DNA among blood donors to be 48%–72%.
It can likely infect a wide range of tissues, as it has been isolated from various body fluids and tissues, including saliva, feces, plasma/serum,
PBMCs, bone marrow, spleen, pancreas, kidneys, nervous tissue, lymph nodes, semen, and cervical swabs.
Its exact transmission mechanism is unknown, but is thought to be possible by blood-borne, sexual, fecal-oral, and respiratory routes.
Recent studies have shown that humans can have multiple infections of TT viruses.
Clinical
Though TTVs are potentially associated with dieases and their pathogenicity has been debated since their discovery, TTMV is not currently known as an explicit cause of any human disease.
TTMV has been isolated from a number of parapneumonic
empyema
An empyema () is a collection or gathering of pus within a naturally existing anatomical cavity. For example, pleural empyema is empyema of the pleural cavity. It must be differentiated from an abscess, which is a collection of pus in a newly for ...
.
[Galmès J, Li Y, Rajoharison A, Ren L, Dollet S, Richard N, Vernet G, Javouhey E, Wang J, Telles JN, Paranhos-Baccalà G (2012) Potential implication of new torque teno mini viruses in parapneumonic empyema in children. Eur Respir J] However, its clinical significance remains unclear.
References
External links
ICTV Virus Taxonomy 2009UniProt Taxonomy*
{{Taxonbar, from=Q4897367
Anelloviridae
Virus genera