''Ribozyviria'' is a
realm of
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...
nucleic acids.
Established in
ICTV TaxoProp 2020.012D, the realm is named after the presence of genomic and antigenomic
ribozymes of the ''
Deltavirus'' type. Additional common features include a rod-like structure, a RNA-binding "delta antigen" encoded in the genome, and animal hosts.
Furthermore, the size range of the genomes of these viruses is between around 1547–1735nt, they encode a
hammerhead ribozyme or a
hepatitis delta virus ribozyme, and their coding capacity only involves one conserved protein. Most lineages of this realm are poorly understood, the notable exception being members of the genus ''Deltavirus'', the causal agents of
Hepatitis D in humans.
This realm of viruses have an unclear origin. They may have derived from
retrozymes (a family of
retrotransposons) or one of the other groups of
mobile genetic elements that descended from retrozymes (i.e.
viroids and
satellites
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotop ...
).
But it was also proposed that they may have originated from
viroids with capsid protein capture.
Taxonomy
Historical development
The first
taxa of this realm to receive acceptance by the ICTV is the species ''Hepatitis delta virus'' and its genus ''Deltavirus'', in 1993. ''Deltavirus'' remained unassigned to any higher taxa until 2018, when the ICTV mistakenly classified ''Deltavirus'' within the then newly established realm, ''
Riboviria
''Riboviria'' is a realm of viruses that includes all viruses that use a homologous RNA-dependent polymerase for replication. It includes RNA viruses that encode an RNA-dependent RNA polymerase, as well as reverse-transcribing viruses (with e ...
''. In 2019, this error was rectified and ''Deltavirus'' returned to its original position. In 2020, ''Hepatitis delta virus'' was abolished and replaced with eight new species, and the taxonomy developed to reach its current form, detailed below.
Current status
''Ribozyviria'' contains a single family, ''Kolmioviridae'', with no intermediate taxa between realm and family. This family contains eight genera.
The names of all genera in this realm allude to
the letter "D" in various languages. The family name comes from
Finnish ''kolmio'' "triangle"; another reference to
the Greek letter "Δ" (delta).
[
This taxonomy is shown hereafter:]Cynops orientalis
The Chinese fire belly newt (''Cynops orientalis'') is a small () black newt, with bright-orange aposematic coloration on their ventral sides. ''C. orientalis'' is commonly seen in pet stores, where it is frequently confused with the Japanese f ...
'')Schedorhinotermes intermedius
''Schedorhinotermes intermedius'' is a species of termite in the family Rhinotermitidae, endemic to eastern Australia.
Description
Members of the worker caste possess internally serrated mandibles, a centrally grooved labrum, a fontanelle, ...
'')Liasis mackloti savuensis
''Liasis mackloti savuensis'', known as the Savu python, is a Pythonidae, python subspecies found in Indonesia. It is known by the locals as ''sanca mata putih'' (white-eyed python).
Distribution and habitat
The Type locality (biology), type lo ...
'')[
**** Species: ''Deltavirus cameroonense'' uman hepatitis delta virus 7 (HDV-7)(host: '']Homo sapiens
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
'')
**** Species: ''Deltavirus carense'' uman hepatitis delta virus 6 (HDV-6)(host: ''H. sapiens'')
**** Species: ''Deltavirus italiense'' uman hepatitis delta virus 1 (HDV-1)
Uman ( uk, Умань, ; pl, Humań; yi, אומאַן) is a city located in Cherkasy Oblast in central Ukraine, to the east of Vinnytsia. Located in the historical region of the eastern Podolia, the city rests on the banks of the Umanka River ...
(host: ''H. sapiens'')
**** Species: ''Deltavirus japanense'' uman hepatitis delta virus 2 (HDV-2)(host: ''H. sapiens'')
**** Species: ''Deltavirus peruense'' uman hepatitis delta virus 3 (HDV-3)(host: ''H. sapiens'')
**** Species: ''Deltavirus senegalense'' uman hepatitis delta virus 8 (HDV-8)(host: ''H. sapiens'')
**** Species: ''Deltavirus taiwanense'' uman hepatitis delta virus 4 (HDV-4)(host: ''H. sapiens'')
**** Species: ''Deltavirus togense'' uman hepatitis delta virus 5 (HDV-5)(host: ''H. sapiens'')
*** Genus: ''Dobrovirus
''Dobrovirus'' is a genus of viruses in the Realm (virology), realm ''Ribozyviria'', containing the single species ''Dobrovirus bufonis''.
Host
The Chusan Island toad (''Bufo gargarizans'') serves as its host.
File:Bufo gargarizans profile. ...
''
**** Species: ''Dobrovirus bufonis'' husan Island toad virus 1 (CITV-1), formerly tfHDV(host: '' Bufo gargarizans'')
See also
* List of higher virus taxa
* Retrozyme
* Viroid
References
Further reading
*
{{Taxonbar, from=Q106951424
Viruses
Virus realms