Orthornavirae

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Orthornavirae
Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Taxonomic characteristics
Genome : RNA
Baltimore : Groups 3, 4, 5
Scientific name
Orthornavirae
Left

The Empire Orthornavirae includes all viruses that an RNA - genome and have a RNA-dependent RNA polymerase (RdRp) encoding . The realm includes dsRNA , (+) ss RNA and (-) ssRNA viruses of the Riboviria range , which contains almost all RNA viruses. This corresponds to groups 3, 4 and 5 of the traditional Baltimore classification . The name of the taxon is derived from the Greek ὀρθός Orthos , German 'straight' , as well as RNA for the type of genome and the suffix -virae for a realm of viruses.

Systematics

The realm Orthornavirae currently contains five phyla , two families and one genus incertae sedis .

Empire Orthornavirae

Simplified cladogram according to Wolf et al (2018):

 Orthornavirae  




Negarnaviricota


   

Duplornaviricota



   

Kitrinoviricota



   

Pisuviricota



   

Lenarviricota



Template: Klade / Maintenance / Style

A detailed representation is given in the following graphic:

Phylogenetic tree with the branching phyla of Negarnaviricota (branch 5, brown), Duplornaviricota (branch 4, green), Kitrinoviricota (branch 3, pink), Pisuviricota (branch 2, blue) and Lenarviricota (branch 1, yellow)

evolution

It is believed that the Orthornavirae RNA viruses originated in the RNA world or in protobionts before the ancestor of all today's cellular organisms ( bacteria , archaea and eukaryotes ). The Lenarviricota lack the capsids - with the exception of some Leviviruses (order Levivirales ). In addition, these have the most divergent proteins compared to the other Orthornavirae viruses , so they could be the origin of most of the mobile genetic elements (MGEs) found in cellular organisms and DNA viruses . Most prokaryote- infecting RNA viruses (RNA phages ) could have become extinct within millions of years or have jumped to eukaryotes, where they found good conditions for their replication, for example in the presence of the eukaryotic cytosol . Conversely, prokaryotes had developed defense mechanisms (such as CRISPR ) during this period that made it impossible for most RNA viruses to replicate in them.

literature

Web links

Individual evidence

  1. ICTV Master Species List 2018b.v2 . MSL # 34, March 2019.
  2. a b Virus Taxonomy: 2019 Release. International Committee on Taxonomy of Viruses (ICTV), accessed April 25, 2020 .
  3. Koonin EV, Dolja VV, Krupovic M, Varsani A, Wolf YI, Yutin N, Zerbini M, Kuhn JH: Proposal: Create a megataxonomic framework, filling all principal taxonomic ranks, for realm Riboviria ( English )
  4. Origins and Evolution of the Global RNA Virome . In: Yuri I. Wolf, Darius Kazlauskas, Jaime Iranzo, Adriana Lucía-Sanz, Jens H. Kuhn, Mart Krupovic, Valerian V. Dolja, Eugene V. Koonin (eds.): MBio . tape 9 , no. 6 , November 27, 2018, ISSN  2150-7511 , doi : 10.1128 / mBio.02329-18 , PMID 30482837 .
  5. also called last universal common ancestor (LUGA), English last universal common ancestor, LUCA
  6. Valerian V. Dolja, Eugene V. Koonin: Capsid-Less RNA Viruses . In: Encyclopedia of Life Sciences . American Cancer Society, 2012, ISBN 978-0-470-01590-2 , doi : 10.1002 / 9780470015902.a0023269 .
  7. ^ Eugene V Koonin, Valerian V Dolja: A virocentric perspective on the evolution of life . In: Current Opinion in Virology . tape 3 , no. 5 , October 2013, ISSN  1879-6257 , p. 546-557 , doi : 10.1016 / j.coviro.2013.06.008 .
  8. ^ Eugene V. Koonin, Valerian V. Dolja: Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements . In: Microbiology and Molecular Biology Reviews: MMBR . tape 78 , no. 2 , June 2014, ISSN  1092-2172 , p. 278-303 , doi : 10.1128 / MMBR.00049-13 , PMID 24847023 , PMC 4054253 (free full text).