Tymovirales
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The order tymovirales is a taxon (lineage) of viruses with single stranded RNA - genome in positive strand orientation that is not linear and segmented. Their representatives are predominantly plant viruses . The name for the order is from the family of viruses Tymoviridae and these in turn from its type species, T urnip y ellow mo saic virus derived. While the virus particles (virions) of the representatives of the family Tymoviridae consist of isometric, icosahedral capsids , the other three families have filamentous, helical capsid symmetries. Due to sequence similarities and similar replication strategies, however, a common evolutionary precursor for all four families can be assumed, which is why the new order Tymovirales was created by the ICTV in 2011 .
Systematics
Internal system
According to the official virus taxonomy of the ICTV, as of November 2018, the order Tymovirales includes the following families:
- Family Alphaflexiviridae
- Genus Allexivirus Type species Shallot virus X
- Genus botrex virus
- Genus Lolavirus , with species Lolium latency virus - en. Lolium latency virus (LoLV)
- Genus Mandarivirus
- Genus Platypuvirus
- Genus Potexvirus
- Genus Sclerodarnavirus
- Family Betaflexiviridae
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- Subfamily Quinvirinae
- Genus Carlavirus
- Genus Foveavirus
- Genus Robigovirus
- Subfamily Trivirinae
- Genus Capillovirus
- Genus chordovirus
- Genus Citrivirus
- Genus Divavirus
- Genus Prunevirus
- Genus Tepovirus
- Genus Trichovirus
- Genus Vitivirus
- Family Gammaflexiviridae
- Genus Mycoflexivirus , type species Botrytis virus F
- Family Deltaflexiviridae
- Genus Deltaflexivirus , type species Sclerotinia deltaflexivirus 1
- Family Tymoviridae
- Genus Maculavirus
- Genus marafivirus
- Genus Tymovirus , type species Turnip yellow mosaic virus
External system
In 2015, Koonin et al assigned the tymovirales taxonomically (due to their relationship) to the supergroup 'Alphavirus-like superfamily' they postulated. According to the authors, the family tree of this supergroup is as follows:
| " Alphavirus- like superfamily " |
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The members of this proposed supergroup belong to different groups of the Baltimore classification , usually single-stranded RNA viruses of positive polarity ((+) ssRNA, Baltimore group 4), but they are also - like the Birnaviridae - double-stranded representatives (marked with dsRNA, Baltimore Group 3).
ICTV Master Species List # 35
With the new Master species List of the ICTV, ratified in March 2020, the following picture emerges:
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Of the Kitrinoviricota , only the classes with the families already mentioned are listed, two more of these families remain unassigned with this status within the Orthornavirae . The "Alphavirus-like superfamily" essentially coincides with the phylum Kitrinoviricota .
As a possible further member of this phylum, a proposed family around the chronic bee paralysis virus (CBPV) could come into question, if the Nodaviridae and the Tombusviridae are its closest relatives, but the differences justify a family of their own (see there).
swell
- AMQ King, MJ Adams, EB Carstens, EJ Lefkowitz (eds.): Virus Taxonomy. Ninth Report of the International Committee on Taxonomy of Viruses. Amsterdam 2012, ISBN 978-0-12-384684-6 , pp. 901ff
Individual evidence
- ↑ ICTV Master Species List 2018b v1 MSL # 34, Feb. 2019
- ↑ a b c d ICTV: ICTV Master Species List 2019.v1 , New MSL including all taxa updates since the 2018b release, March 2020 (MSL # 35)
- ↑ SIB: Alphaflexiviridae , on: ViralZone
- ↑ SIB: Allexivirus , on: ViralZone
- ^ S. Majumder, M. Arya, RP Pant, VK Baranwal: Shallot virus X in Indian shallot, a new virus report for India , in: New Disease Reports (2007) 15, 52, ISSN 2044-0588
- ↑ SIB: Mandarivirus , on: ViralZone
- ↑ SIB: Potexvirus , on: ViralZone
- ↑ SIB: Betaflexiviridae , on: ViralZone
- ↑ SIB: Carlavirus , on: ViralZone
- ↑ SIB: Foveavirus , on: ViralZone
- ↑ SIB: Capillovirus , on: ViralZone
- ↑ SIB: Trichovirus , on: ViralZone
- ↑ SIB: Vitivirus , on: ViralZone
- ↑ SIB: Gammaflexiviridae , on: ViralZone
- ↑ SIB: Deltaflexiviridae , on: ViralZone
- ↑ SIB: Tymoviridae , on: ViralZone
- ↑ In older papers (with a different phylogeny) there is also the term 'Sindbis-like supergroup', Sindbis virus is a species in the genus Alphavirus , family Togaviridae . Since this group (referred to by the authors as English superfamily ) contains an order with the Tymovirales , their rank must be higher than this and should not be understood as a superfamily . Ranks higher than order were not given by the ICTV at the time of the work.
- ^ Eugene V. Koonin, Valerian V. Dolja, Mart Krupovic: Origins and evolution of viruses of eukaryotes: The ultimate modularity , in: Virology from May 2015; 479-480. 2-25, Epub March 12, 2015, PMC 5898234 (free full text), PMID 25771806
- ↑ SIB: Alphatetraviridae , on: ViralZone
- ↑ SIB: Carmotetraviridae , on: ViralZone
- ↑ SIB: Permutotetraviridae , on: ViralZone
- ↑ SIB: Nodaviridae , on: ViralZone
- ↑ ICTV: ICTV Taxonomy history: Alfalfa enamovirus 1 , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)