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RNA virus

An RNA virus is a virus—other than a retrovirus—that has ribonucleic acid (RNA) as its genetic material.[1] The nucleic acid is usually single-stranded RNA (ssRNA) but it may be double-stranded (dsRNA).[2] Notable human diseases caused by RNA viruses include the common cold, influenza, SARS, MERS, COVID-19, Dengue Virus, hepatitis C, hepatitis E, West Nile fever, Ebola virus disease, rabies, polio, mumps, and measles.

Taxonomy and replication strategies of different types of RNA viruses

The International Committee on Taxonomy of Viruses (ICTV) classifies RNA viruses as those that belong to Group III, Group IV or Group V of the Baltimore classification system. This category excludes Group VI, viruses with RNA genetic material but which use DNA intermediates in their life cycle: these are called retroviruses,[3] including HIV-1 and HIV-2 which cause AIDS.

As of May 2020, all known RNA viruses encoding an RNA-directed RNA polymerase are believed to form a monophyletic group, known as the realm Riboviria.[4] The majority of such RNA viruses fall into the kingdom Orthornavirae and the rest have a positioning not yet defined.[5] The realm does not contain all RNA viruses: Deltavirus, Asunviroidae, and Pospiviroidae are taxa of RNA viruses that were mistakenly included in 2019,[a] but corrected in 2020.[6]

Characteristics edit

Single-stranded RNA viruses and RNA Sense edit

RNA viruses can be further classified according to the sense or polarity of their RNA into negative-sense and positive-sense, or ambisense RNA viruses. Positive-sense viral RNA is similar to mRNA and thus can be immediately translated by the host cell. Negative-sense viral RNA is complementary to mRNA and thus must be converted to positive-sense RNA by an RNA-dependent RNA polymerase before translation. Purified RNA of a positive-sense virus can directly cause infection though it may be less infectious than the whole virus particle. In contrast, purified RNA of a negative-sense virus is not infectious by itself as it needs to be transcribed into positive-sense RNA; each virion can be transcribed to several positive-sense RNAs. Ambisense RNA viruses resemble negative-sense RNA viruses, except they translate genes from their negative and positive strands.[7]

Double-stranded RNA viruses edit

 
Structure of the reovirus virion

The double-stranded (ds)RNA viruses represent a diverse group of viruses that vary widely in host range (humans, animals, plants, fungi,[b] and bacteria), genome segment number (one to twelve), and virion organization (Triangulation number, capsid layers, spikes, turrets, etc.). Members of this group include the rotaviruses, which are the most common cause of gastroenteritis in young children, and picobirnaviruses, which are the most common virus in fecal samples of both humans and animals with or without signs of diarrhea. Bluetongue virus is an economically important pathogen that infects cattle and sheep. In recent years, progress has been made in determining atomic and subnanometer resolution structures of a number of key viral proteins and virion capsids of several dsRNA viruses, highlighting the significant parallels in the structure and replicative processes of many of these viruses.[2][page needed]

Mutation rates edit

RNA viruses generally have very high mutation rates compared to DNA viruses,[9] because viral RNA polymerases lack the proofreading ability of DNA polymerases.[10] The genetic diversity of RNA viruses is one reason why it is difficult to make effective vaccines against them.[11] Retroviruses also have a high mutation rate even though their DNA intermediate integrates into the host genome (and is thus subject to host DNA proofreading once integrated), because errors during reverse transcription are embedded into both strands of DNA before integration.[12] Some genes of RNA virus are important to the viral replication cycles and mutations are not tolerated. For example, the region of the hepatitis C virus genome that encodes the core protein is highly conserved,[13] because it contains an RNA structure involved in an internal ribosome entry site.[14]

Sequence complexity edit

On average, dsRNA viruses show a lower sequence redundancy relative to ssRNA viruses. Contrarily, dsDNA viruses contain the most redundant genome sequences while ssDNA viruses have the least.[15] The sequence complexity of viruses has been shown to be a key characteristic for accurate reference-free viral classification.[15]

Replication edit

Animal RNA viruses are classified by the ICTV. There are three distinct groups of RNA viruses depending on their genome and mode of replication:

  • Double-stranded RNA viruses (Group III) contain from one to a dozen different RNA molecules, each coding for one or more viral proteins.
  • Positive-sense ssRNA viruses (Group IV) have their genome directly utilized as mRNA, with host ribosomes translating it into a single protein that is modified by host and viral proteins to form the various proteins needed for replication. One of these includes RNA-dependent RNA polymerase (RNA replicase), which copies the viral RNA to form a double-stranded replicative form. In turn, this dsRNA directs the formation of new viral RNA.
  • Negative-sense ssRNA viruses (Group V) must have their genome copied by an RNA replicase to form positive-sense RNA. This means that the virus must bring along with it the enzyme RNA replicase. The positive-sense RNA molecule then acts as viral mRNA, which is translated into proteins by the host ribosomes.

Retroviruses (Group VI) have a single-stranded RNA genome but, in general, are not considered RNA viruses because they use DNA intermediates to replicate. Reverse transcriptase, a viral enzyme that comes from the virus itself after it is uncoated, converts the viral RNA into a complementary strand of DNA, which is copied to produce a double-stranded molecule of viral DNA. After this DNA is integrated into the host genome using the viral enzyme integrase, expression of the encoded genes may lead to the formation of new virions.

Recombination edit

Numerous RNA viruses are capable of genetic recombination when at least two viral genomes are present in the same host cell.[16] Very rarely viral RNA can recombine with host RNA.[17] RNA recombination appears to be a major driving force in determining genome architecture and the course of viral evolution among Picornaviridae ((+)ssRNA), e.g. poliovirus.[18] In the Retroviridae ((+)ssRNA), e.g. HIV, damage in the RNA genome appears to be avoided during reverse transcription by strand switching, a form of recombination.[19][20][21] Recombination also occurs in the Reoviridae (dsRNA), e.g. reovirus; Orthomyxoviridae ((-)ssRNA), e.g. influenza virus;[21] and Coronaviridae ((+)ssRNA), e.g. SARS.[22] Recombination in RNA viruses appears to be an adaptation for coping with genome damage.[16] Recombination can occur infrequently between animal viruses of the same species but of divergent lineages. The resulting recombinant viruses may sometimes cause an outbreak of infection in humans.[22]

Classification edit

Classification is based principally on the type of genome (double-stranded, negative- or positive-single-strand) and gene number and organization. Currently, there are 5 orders and 47 families of RNA viruses recognized. There are also many unassigned species and genera.

Related to but distinct from the RNA viruses are the viroids and the RNA satellite viruses. These are not currently classified as RNA viruses and are described on their own pages.

A study of several thousand RNA viruses has shown the presence of at least five main taxa: a levivirus and relatives group; a picornavirus supergroup; an alphavirus supergroup plus a flavivirus supergroup; the dsRNA viruses; and the -ve strand viruses.[23] The lentivirus group appears to be basal to all the remaining RNA viruses. The next major division lies between the picornasupragroup and the remaining viruses. The dsRNA viruses appear to have evolved from a +ve RNA ancestor and the -ve RNA viruses from within the dsRNA viruses. The closest relation to the -ve stranded RNA viruses is the Reoviridae.

Positive-strand RNA viruses edit

This is the single largest group of RNA viruses[24] and has been organized by the ICTV into the phyla Kitrinoviricota, Lenarviricota, and Pisuviricota in the kingdom Orthornavirae and realm Riboviria.[25]

Positive-strand RNA viruses can also be classified based on the RNA-dependent RNA polymerase. Three groups have been recognised:[26]

  1. Bymoviruses, comoviruses, nepoviruses, nodaviruses, picornaviruses, potyviruses, sobemoviruses and a subset of luteoviruses (beet western yellows virus and potato leafroll virus)—the picorna like group (Picornavirata).
  2. Carmoviruses, dianthoviruses, flaviviruses, pestiviruses, statoviruses, tombusviruses, single-stranded RNA bacteriophages, hepatitis C virus and a subset of luteoviruses (barley yellow dwarf virus)—the flavi like group (Flavivirata).
  3. Alphaviruses, carlaviruses, furoviruses, hordeiviruses, potexviruses, rubiviruses, tobraviruses, tricornaviruses, tymoviruses, apple chlorotic leaf spot virus, beet yellows virus and hepatitis E virus—the alpha like group (Rubivirata).

A division of the alpha-like (Sindbis-like) supergroup on the basis of a novel domain located near the N termini of the proteins involved in viral replication has been proposed.[27] The two groups proposed are: the 'altovirus' group (alphaviruses, furoviruses, hepatitis E virus, hordeiviruses, tobamoviruses, tobraviruses, tricornaviruses and probably rubiviruses); and the 'typovirus' group (apple chlorotic leaf spot virus, carlaviruses, potexviruses and tymoviruses).

The alpha like supergroup can be further divided into three clades: the rubi-like, tobamo-like, and tymo-like viruses.[28]

Additional work has identified five groups of positive-stranded RNA viruses containing four, three, three, three, and one order(s), respectively.[29] These fourteen orders contain 31 virus families (including 17 families of plant viruses) and 48 genera (including 30 genera of plant viruses). This analysis suggests that alphaviruses and flaviviruses can be separated into two families—the Togaviridae and Flaviridae, respectively—but suggests that other taxonomic assignments, such as the pestiviruses, hepatitis C virus, rubiviruses, hepatitis E virus, and arteriviruses, may be incorrect. The coronaviruses and toroviruses appear to be distinct families in distinct orders and not distinct genera of the same family as currently classified. The luteoviruses appear to be two families rather than one, and apple chlorotic leaf spot virus appears not to be a closterovirus but a new genus of the Potexviridae.

Evolution edit

The evolution of the picornaviruses based on an analysis of their RNA polymerases and helicases appears to date to the divergence of eukaryotes.[30] Their putative ancestors include the bacterial group II retroelements, the family of HtrA proteases and DNA bacteriophages.

Partitiviruses are related to and may have evolved from a totivirus ancestor.[31]

Hypoviruses and barnaviruses appear to share an ancestry with the potyvirus and sobemovirus lineages respectively.[31]

Double-stranded RNA viruses edit

This analysis also suggests that the dsRNA viruses are not closely related to each other but instead belong to four additional classes—Birnaviridae, Cystoviridae, Partitiviridae, and Reoviridae—and one additional order (Totiviridae) of one of the classes of positive ssRNA viruses in the same subphylum as the positive-strand RNA viruses.

One study has suggested that there are two large clades: One includes the families Caliciviridae, Flaviviridae, and Picornaviridae and a second that includes the families Alphatetraviridae, Birnaviridae, Cystoviridae, Nodaviridae, and Permutotretraviridae.[32]

Negative strand RNA viruses edit

These viruses have multiple types of genome ranging from a single RNA molecule up to eight segments. Despite their diversity it appears that they may have originated in arthropods and to have diversified from there.[33]

Satellite viruses edit

A number of satellite viruses—viruses that require the assistance of another virus to complete their life cycle—are also known. Their taxonomy has yet to be settled. The following four genera have been proposed for positive sense single stranded RNA satellite viruses that infect plants—Albetovirus, Aumaivirus, Papanivirus and Virtovirus.[34] A family—Sarthroviridae which includes the genus Macronovirus—has been proposed for the positive sense single stranded RNA satellite viruses that infect arthropods.

Group III – dsRNA viruses edit

There are twelve families and a number of unassigned genera and species recognised in this group.[10]

Group IV – positive-sense ssRNA viruses edit

There are three orders and 34 families recognised in this group. In addition, there are a number of unclassified species and genera.

Satellite viruses

An unclassified astrovirus/hepevirus-like virus has also been described.[36]

Group V – negative-sense ssRNA viruses edit

With the exception of the Hepatitis D virus, this group of viruses has been placed into a single phylum—Negarnaviricota. This phylum has been divided into two subphyla—Haploviricotina and Polyploviricotina. Within the subphylum Haploviricotina four classes are currently recognised: Chunqiuviricetes, Milneviricetes, Monjiviricetes and Yunchangviricetes. In the subphylum Polyploviricotina two classes are recognised: Ellioviricetes and Insthoviricetes.

Six classes, seven orders and twenty four families are currently recognized in this group. A number of unassigned species and genera are yet to be classified.[10]

Gallery edit

See also edit

Notes edit

  1. ^ This inclusion was due to TaxoProp 2017.006G, which proposed Riboviria. The confusion might be due to the TaxoProp's reference to a "monophyly of all RNA viruses", improperly termed as it was only demonstrated with RdRP. On the other hand, the proposed definition of Riboviria did correctly mention RdRP .
  2. ^ The majority of fungal viruses are double-stranded RNA viruses. A small number of positive-strand RNA viruses have been described. One report has suggested the possibility of a negative stranded virus.[8]

References edit

  1. ^ Wagner, Edward K.; Hewlett, Martinez J. (1999). Basic virology. Malden, MA: Blackwell Science, Inc. p. 249. ISBN 0-632-04299-0. Retrieved 30 March 2020.
  2. ^ a b Patton JT, ed. (2008). Segmented Double-stranded RNA Viruses: Structure and Molecular Biology. Caister Academic Press. ISBN 978-1-904455-21-9.
  3. ^ "Listing in Taxonomic Order – Index to ICTV Species Lists". Retrieved 11 April 2008.
  4. ^ International Committee on Taxonomy of Viruses Executive Committee (May 2020). "The new scope of virus taxonomy: partitioning the virosphere into 15 hierarchical ranks". Nature Microbiology. 5 (5): 668–674. doi:10.1038/s41564-020-0709-x. PMC 7186216. PMID 32341570.
  5. ^ TaxoProp 2019.006G
  6. ^ TaxoProp 2019.009G
  7. ^ Nguyen M, Haenni AL (June 2003). "Expression strategies of ambisense viruses". Virus Research. 93 (2): 141–50. doi:10.1016/S0168-1702(03)00094-7. PMID 12782362.
  8. ^ Kondo H, Chiba S, Toyoda K, Suzuki N (January 2013). "Evidence for negative-strand RNA virus infection in fungi". Virology. 435 (2): 201–09. doi:10.1016/j.virol.2012.10.002. PMID 23099204.
  9. ^ Sanjuán R, Nebot MR, Chirico N, Mansky LM, Belshaw R (October 2010). "Viral mutation rates". Journal of Virology. 84 (19): 9733–48. doi:10.1128/JVI.00694-10. PMC 2937809. PMID 20660197.
  10. ^ a b c Klein DW, Prescott LM, Harley J (1993). Microbiology. Dubuque, Iowa: Wm. C. Brown. ISBN 978-0-697-01372-9.
  11. ^ Steinhauer DA, Holland JJ (1987). "Rapid evolution of RNA viruses". Annual Review of Microbiology. 41: 409–33. doi:10.1146/annurev.mi.41.100187.002205. PMID 3318675.
  12. ^ Boutwell CL, Rolland MM, Herbeck JT, Mullins JI, Allen TM (October 2010). "Viral evolution and escape during acute HIV-1 infection". The Journal of Infectious Diseases. 202 (Suppl 2): S309–14. doi:10.1086/655653. PMC 2945609. PMID 20846038.
  13. ^ Bukh J, Purcell RH, Miller RH (August 1994). "Sequence analysis of the core gene of 14 hepatitis C virus genotypes". Proceedings of the National Academy of Sciences of the United States of America. 91 (17): 8239–43. Bibcode:1994PNAS...91.8239B. doi:10.1073/pnas.91.17.8239. PMC 44581. PMID 8058787.
  14. ^ Tuplin A, Evans DJ, Simmonds P (October 2004). "Detailed mapping of RNA secondary structures in core and NS5B-encoding region sequences of hepatitis C virus by RNase cleavage and novel bioinformatic prediction methods". The Journal of General Virology. 85 (Pt 10): 3037–47. doi:10.1099/vir.0.80141-0. PMID 15448367.
  15. ^ a b Silva JM, Pratas D, Caetano T, Matos D (August 2022). "The complexity landscape of viral genomes". GigaScience. 11: 1–16. doi:10.1093/gigascience/giac079. PMC 9366995. PMID 35950839.
  16. ^ a b Barr JN, Fearns R (June 2010). "How RNA viruses maintain their genome integrity". The Journal of General Virology. 91 (Pt 6): 1373–87. doi:10.1099/vir.0.020818-0. PMID 20335491.
  17. ^ Stedman, Kenneth M. (2015). "Deep Recombination: RNA and ssDNA Virus Genes in DNA Virus and Host Genomes". Annual Review of Virology. 2 (1): 203–217. doi:10.1146/annurev-virology-100114-055127. ISSN 2327-0578. PMID 26958913. S2CID 207745438.
  18. ^ Muslin C, Mac Kain A, Bessaud M, Blondel B, Delpeyroux F (September 2019). "Recombination in Enteroviruses, a Multi-Step Modular Evolutionary Process". Viruses. 11 (9): 859. doi:10.3390/v11090859. PMC 6784155. PMID 31540135.
  19. ^ Hu WS, Temin HM (November 1990). "Retroviral recombination and reverse transcription". Science. 250 (4985): 1227–33. Bibcode:1990Sci...250.1227H. doi:10.1126/science.1700865. PMID 1700865.
  20. ^ Rawson JM, Nikolaitchik OA, Keele BF, Pathak VK, Hu WS (November 2018). "Recombination is required for efficient HIV-1 replication and the maintenance of viral genome integrity". Nucleic Acids Research. 46 (20): 10535–45. doi:10.1093/nar/gky910. PMC 6237782. PMID 30307534.
  21. ^ a b Bernstein H, Bernstein C, Michod RE (January 2018). "Sex in microbial pathogens". Infection, Genetics and Evolution. 57: 8–25. doi:10.1016/j.meegid.2017.10.024. PMID 29111273.
  22. ^ a b Su S, Wong G, Shi W, Liu J, Lai AC, Zhou J, et al. (June 2016). "Epidemiology, Genetic Recombination, and Pathogenesis of Coronaviruses". Trends in Microbiology. 24 (6): 490–502. doi:10.1016/j.tim.2016.03.003. PMC 7125511. PMID 27012512.
  23. ^ Wolf YI, Kazlauskas D, Iranzo J, Lucía-Sanz A, Kuhn JH, Krupovic M, Dolja VV, Koonin EV (November 2018). "Origins and Evolution of the Global RNA Virome". mBio. 9 (6). doi:10.1128/mBio.02329-18. PMC 6282212. PMID 30482837.
  24. ^ Francki RI, Fauquet CM, Knudson DL, Brown F (1991). Classification and nomenclature of viruses. Fifth report of the International Committee on Taxonomy of Viruses, Archives of Virology (Suppl. 2). Springer. ISBN 978-3-7091-9163-7.
  25. ^ "Current ICTV Taxonomy Release | ICTV". ictv.global. Retrieved 3 April 2023.
  26. ^ Koonin EV (September 1991). "The phylogeny of RNA-dependent RNA polymerases of positive-strand RNA viruses". The Journal of General Virology. 72 (Pt 9): 2197–206. doi:10.1099/0022-1317-72-9-2197. PMID 1895057.
  27. ^ Rozanov MN, Koonin EV, Gorbalenya AE (August 1992). "Conservation of the putative methyltransferase domain: a hallmark of the 'Sindbis-like' supergroup of positive-strand RNA viruses". The Journal of General Virology. 73 (Pt 8): 2129–34. CiteSeerX 10.1.1.532.7367. doi:10.1099/0022-1317-73-8-2129. PMID 1645151.
  28. ^ Koonin EV, Dolja VV (1993). "Evolution and taxonomy of positive-strand RNA viruses: implications of comparative analysis of amino acid sequences". Critical Reviews in Biochemistry and Molecular Biology. 28 (5): 375–430. doi:10.3109/10409239309078440. PMID 8269709.
  29. ^ Ward CW (1993). "Progress towards a higher taxonomy of viruses". Research in Virology. 144 (6): 419–53. doi:10.1016/S0923-2516(06)80059-2. PMC 7135741. PMID 8140287.
  30. ^ Koonin EV, Wolf YI, Nagasaki K, Dolja VV (December 2008). "The Big Bang of picorna-like virus evolution antedates the radiation of eukaryotic supergroups". Nature Reviews. Microbiology. 6 (12): 925–39. doi:10.1038/nrmicro2030. PMID 18997823.
  31. ^ a b Ghabrial SA (1998). "Origin, adaptation and evolutionary pathways of fungal viruses". Virus Genes. 16 (1): 119–31. doi:10.1023/a:1007966229595. PMC 7089520. PMID 9562896.
  32. ^ Gibrat JF, Mariadassou M, Boudinot P, Delmas B (July 2013). "Analyses of the radiation of birnaviruses from diverse host phyla and of their evolutionary affinities with other double-stranded RNA and positive strand RNA viruses using robust structure-based multiple sequence alignments and advanced phylogenetic methods". BMC Evolutionary Biology. 13: 154. doi:10.1186/1471-2148-13-154. PMC 3724706. PMID 23865988.
  33. ^ Li CX, Shi M, Tian JH, Lin XD, Kang YJ, Chen LJ, et al. (January 2015). "Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA viruses". eLife. 4. doi:10.7554/eLife.05378. PMC 4384744. PMID 25633976.
  34. ^ Krupovic M, Kuhn JH, Fischer MG (January 2016). "A classification system for virophages and satellite viruses". Archives of Virology. 161 (1): 233–47. doi:10.1007/s00705-015-2622-9. hdl:11858/00-001M-0000-0028-DC34-F. PMID 26446887.
  35. ^ Adams MJ, Antoniw JF, Kreuze J (2009). "Virgaviridae: a new family of rod-shaped plant viruses". Archives of Virology. 154 (12): 1967–72. doi:10.1007/s00705-009-0506-6. PMID 19862474.
  36. ^ Pankovics P, Boros Á, Kiss T, Engelmann P, Reuter G (2019) Genetically highly divergent RNA virus with astrovirus-like (5'-end) and hepevirus-like (3'-end) genome organization in carnivorous birds, European roller (Coracias garrulus). Infect Genet Evol
  37. ^ "Virus Taxonomy: 2018 Release". International Committee on Taxonomy of Viruses. Retrieved 13 November 2018.
  38. ^ Mihindukulasuriya KA, Nguyen NL, Wu G, Huang HV, da Rosa AP, Popov VL, et al. (May 2009). "Nyamanini and midway viruses define a novel taxon of RNA viruses in the order Mononegavirales". Journal of Virology. 83 (10): 5109–16. doi:10.1128/JVI.02667-08. PMC 2682064. PMID 19279111.

External links edit

virus, parts, this, article, those, related, taxonomy, baltimore, sections, ictv, release, 2018b, 2019, need, updated, please, help, update, this, article, reflect, recent, events, newly, available, information, january, 2021, virus, other, than, retrovirus, t. Parts of this article those related to taxonomy in baltimore sections ICTV release 2018b 2019 need to be updated Please help update this article to reflect recent events or newly available information January 2021 An RNA virus is a virus other than a retrovirus that has ribonucleic acid RNA as its genetic material 1 The nucleic acid is usually single stranded RNA ssRNA but it may be double stranded dsRNA 2 Notable human diseases caused by RNA viruses include the common cold influenza SARS MERS COVID 19 Dengue Virus hepatitis C hepatitis E West Nile fever Ebola virus disease rabies polio mumps and measles Taxonomy and replication strategies of different types of RNA virusesThe International Committee on Taxonomy of Viruses ICTV classifies RNA viruses as those that belong to Group III Group IV or Group V of the Baltimore classification system This category excludes Group VI viruses with RNA genetic material but which use DNA intermediates in their life cycle these are called retroviruses 3 including HIV 1 and HIV 2 which cause AIDS As of May 2020 all known RNA viruses encoding an RNA directed RNA polymerase are believed to form a monophyletic group known as the realm Riboviria 4 The majority of such RNA viruses fall into the kingdom Orthornavirae and the rest have a positioning not yet defined 5 The realm does not contain all RNA viruses Deltavirus Asunviroidae and Pospiviroidae are taxa of RNA viruses that were mistakenly included in 2019 a but corrected in 2020 6 Contents 1 Characteristics 1 1 Single stranded RNA viruses and RNA Sense 1 2 Double stranded RNA viruses 1 3 Mutation rates 1 4 Sequence complexity 2 Replication 3 Recombination 4 Classification 4 1 Positive strand RNA viruses 4 1 1 Evolution 4 2 Double stranded RNA viruses 4 3 Negative strand RNA viruses 4 4 Satellite viruses 5 Group III dsRNA viruses 6 Group IV positive sense ssRNA viruses 7 Group V negative sense ssRNA viruses 8 Gallery 9 See also 10 Notes 11 References 12 External linksCharacteristics editSingle stranded RNA viruses and RNA Sense edit RNA viruses can be further classified according to the sense or polarity of their RNA into negative sense and positive sense or ambisense RNA viruses Positive sense viral RNA is similar to mRNA and thus can be immediately translated by the host cell Negative sense viral RNA is complementary to mRNA and thus must be converted to positive sense RNA by an RNA dependent RNA polymerase before translation Purified RNA of a positive sense virus can directly cause infection though it may be less infectious than the whole virus particle In contrast purified RNA of a negative sense virus is not infectious by itself as it needs to be transcribed into positive sense RNA each virion can be transcribed to several positive sense RNAs Ambisense RNA viruses resemble negative sense RNA viruses except they translate genes from their negative and positive strands 7 Double stranded RNA viruses edit Further information Double stranded RNA viruses nbsp Structure of the reovirus virionThe double stranded ds RNA viruses represent a diverse group of viruses that vary widely in host range humans animals plants fungi b and bacteria genome segment number one to twelve and virion organization Triangulation number capsid layers spikes turrets etc Members of this group include the rotaviruses which are the most common cause of gastroenteritis in young children and picobirnaviruses which are the most common virus in fecal samples of both humans and animals with or without signs of diarrhea Bluetongue virus is an economically important pathogen that infects cattle and sheep In recent years progress has been made in determining atomic and subnanometer resolution structures of a number of key viral proteins and virion capsids of several dsRNA viruses highlighting the significant parallels in the structure and replicative processes of many of these viruses 2 page needed Mutation rates edit RNA viruses generally have very high mutation rates compared to DNA viruses 9 because viral RNA polymerases lack the proofreading ability of DNA polymerases 10 The genetic diversity of RNA viruses is one reason why it is difficult to make effective vaccines against them 11 Retroviruses also have a high mutation rate even though their DNA intermediate integrates into the host genome and is thus subject to host DNA proofreading once integrated because errors during reverse transcription are embedded into both strands of DNA before integration 12 Some genes of RNA virus are important to the viral replication cycles and mutations are not tolerated For example the region of the hepatitis C virus genome that encodes the core protein is highly conserved 13 because it contains an RNA structure involved in an internal ribosome entry site 14 Sequence complexity edit On average dsRNA viruses show a lower sequence redundancy relative to ssRNA viruses Contrarily dsDNA viruses contain the most redundant genome sequences while ssDNA viruses have the least 15 The sequence complexity of viruses has been shown to be a key characteristic for accurate reference free viral classification 15 Replication editAnimal RNA viruses are classified by the ICTV There are three distinct groups of RNA viruses depending on their genome and mode of replication Double stranded RNA viruses Group III contain from one to a dozen different RNA molecules each coding for one or more viral proteins Positive sense ssRNA viruses Group IV have their genome directly utilized as mRNA with host ribosomes translating it into a single protein that is modified by host and viral proteins to form the various proteins needed for replication One of these includes RNA dependent RNA polymerase RNA replicase which copies the viral RNA to form a double stranded replicative form In turn this dsRNA directs the formation of new viral RNA Negative sense ssRNA viruses Group V must have their genome copied by an RNA replicase to form positive sense RNA This means that the virus must bring along with it the enzyme RNA replicase The positive sense RNA molecule then acts as viral mRNA which is translated into proteins by the host ribosomes Retroviruses Group VI have a single stranded RNA genome but in general are not considered RNA viruses because they use DNA intermediates to replicate Reverse transcriptase a viral enzyme that comes from the virus itself after it is uncoated converts the viral RNA into a complementary strand of DNA which is copied to produce a double stranded molecule of viral DNA After this DNA is integrated into the host genome using the viral enzyme integrase expression of the encoded genes may lead to the formation of new virions Recombination editNumerous RNA viruses are capable of genetic recombination when at least two viral genomes are present in the same host cell 16 Very rarely viral RNA can recombine with host RNA 17 RNA recombination appears to be a major driving force in determining genome architecture and the course of viral evolution among Picornaviridae ssRNA e g poliovirus 18 In the Retroviridae ssRNA e g HIV damage in the RNA genome appears to be avoided during reverse transcription by strand switching a form of recombination 19 20 21 Recombination also occurs in the Reoviridae dsRNA e g reovirus Orthomyxoviridae ssRNA e g influenza virus 21 and Coronaviridae ssRNA e g SARS 22 Recombination in RNA viruses appears to be an adaptation for coping with genome damage 16 Recombination can occur infrequently between animal viruses of the same species but of divergent lineages The resulting recombinant viruses may sometimes cause an outbreak of infection in humans 22 Classification editThis section may require cleanup to meet Wikipedia s quality standards The specific problem is outdated and redundant with riboviria article as well as later text see DNA virus for a clean integration between ICTV higher order and Baltimore Please help improve this section if you can January 2021 Learn how and when to remove this template message Classification is based principally on the type of genome double stranded negative or positive single strand and gene number and organization Currently there are 5 orders and 47 families of RNA viruses recognized There are also many unassigned species and genera Related to but distinct from the RNA viruses are the viroids and the RNA satellite viruses These are not currently classified as RNA viruses and are described on their own pages A study of several thousand RNA viruses has shown the presence of at least five main taxa a levivirus and relatives group a picornavirus supergroup an alphavirus supergroup plus a flavivirus supergroup the dsRNA viruses and the ve strand viruses 23 The lentivirus group appears to be basal to all the remaining RNA viruses The next major division lies between the picornasupragroup and the remaining viruses The dsRNA viruses appear to have evolved from a ve RNA ancestor and the ve RNA viruses from within the dsRNA viruses The closest relation to the ve stranded RNA viruses is the Reoviridae Positive strand RNA viruses edit This is the single largest group of RNA viruses 24 and has been organized by the ICTV into the phyla Kitrinoviricota Lenarviricota and Pisuviricota in the kingdom Orthornavirae and realm Riboviria 25 Positive strand RNA viruses can also be classified based on the RNA dependent RNA polymerase Three groups have been recognised 26 Bymoviruses comoviruses nepoviruses nodaviruses picornaviruses potyviruses sobemoviruses and a subset of luteoviruses beet western yellows virus and potato leafroll virus the picorna like group Picornavirata Carmoviruses dianthoviruses flaviviruses pestiviruses statoviruses tombusviruses single stranded RNA bacteriophages hepatitis C virus and a subset of luteoviruses barley yellow dwarf virus the flavi like group Flavivirata Alphaviruses carlaviruses furoviruses hordeiviruses potexviruses rubiviruses tobraviruses tricornaviruses tymoviruses apple chlorotic leaf spot virus beet yellows virus and hepatitis E virus the alpha like group Rubivirata A division of the alpha like Sindbis like supergroup on the basis of a novel domain located near the N termini of the proteins involved in viral replication has been proposed 27 The two groups proposed are the altovirus group alphaviruses furoviruses hepatitis E virus hordeiviruses tobamoviruses tobraviruses tricornaviruses and probably rubiviruses and the typovirus group apple chlorotic leaf spot virus carlaviruses potexviruses and tymoviruses The alpha like supergroup can be further divided into three clades the rubi like tobamo like and tymo like viruses 28 Additional work has identified five groups of positive stranded RNA viruses containing four three three three and one order s respectively 29 These fourteen orders contain 31 virus families including 17 families of plant viruses and 48 genera including 30 genera of plant viruses This analysis suggests that alphaviruses and flaviviruses can be separated into two families the Togaviridae and Flaviridae respectively but suggests that other taxonomic assignments such as the pestiviruses hepatitis C virus rubiviruses hepatitis E virus and arteriviruses may be incorrect The coronaviruses and toroviruses appear to be distinct families in distinct orders and not distinct genera of the same family as currently classified The luteoviruses appear to be two families rather than one and apple chlorotic leaf spot virus appears not to be a closterovirus but a new genus of the Potexviridae Evolution edit The evolution of the picornaviruses based on an analysis of their RNA polymerases and helicases appears to date to the divergence of eukaryotes 30 Their putative ancestors include the bacterial group II retroelements the family of HtrA proteases and DNA bacteriophages Partitiviruses are related to and may have evolved from a totivirus ancestor 31 Hypoviruses and barnaviruses appear to share an ancestry with the potyvirus and sobemovirus lineages respectively 31 Double stranded RNA viruses edit This analysis also suggests that the dsRNA viruses are not closely related to each other but instead belong to four additional classes Birnaviridae Cystoviridae Partitiviridae and Reoviridae and one additional order Totiviridae of one of the classes of positive ssRNA viruses in the same subphylum as the positive strand RNA viruses One study has suggested that there are two large clades One includes the families Caliciviridae Flaviviridae and Picornaviridae and a second that includes the families Alphatetraviridae Birnaviridae Cystoviridae Nodaviridae and Permutotretraviridae 32 Negative strand RNA viruses edit These viruses have multiple types of genome ranging from a single RNA molecule up to eight segments Despite their diversity it appears that they may have originated in arthropods and to have diversified from there 33 Satellite viruses edit A number of satellite viruses viruses that require the assistance of another virus to complete their life cycle are also known Their taxonomy has yet to be settled The following four genera have been proposed for positive sense single stranded RNA satellite viruses that infect plants Albetovirus Aumaivirus Papanivirus and Virtovirus 34 A family Sarthroviridae which includes the genus Macronovirus has been proposed for the positive sense single stranded RNA satellite viruses that infect arthropods Group III dsRNA viruses editMain article Double stranded RNA viruses There are twelve families and a number of unassigned genera and species recognised in this group 10 Family Amalgaviridae Family Birnaviridae Family Chrysoviridae Family Cystoviridae Family Endornaviridae Family Hypoviridae Family Megabirnaviridae Family Partitiviridae Family Picobirnaviridae Family Reoviridae includes Rotavirus Family Totiviridae Family Quadriviridae Genus Botybirnavirus Unassigned species Botrytis porri RNA virus 1 Circulifer tenellus virus 1 Colletotrichum camelliae filamentous virus 1 Cucurbit yellows associated virus Sclerotinia sclerotiorum debilitation associated virus Spissistilus festinus virus 1Group IV positive sense ssRNA viruses editMain article Positive sense single stranded RNA virus There are three orders and 34 families recognised in this group In addition there are a number of unclassified species and genera Order Nidovirales Family Arteriviridae Family Coronaviridae includes Human coronavirus common cold viruses HCoV 229E HCoV HKU1 HCoV NL63 and HCoV OC43 MERS CoV SARS CoV 1 and SARS CoV 2 Family Mesoniviridae Family Roniviridae Order Picornavirales Family Dicistroviridae Family Iflaviridae Family Marnaviridae Family Picornaviridae includes Poliovirus Rhinovirus a common cold virus Hepatitis A virus Family Secoviridae includes subfamily Comovirinae Genus Bacillariornavirus Species Kelp fly virus Order Tymovirales Family Alphaflexiviridae Family Betaflexiviridae Family Gammaflexiviridae Family Tymoviridae Unassigned Family Alphatetraviridae Family Alvernaviridae Family Astroviridae Family Barnaviridae Family Benyviridae Family Botourmiaviridae Family Bromoviridae Family Caliciviridae includes Norwalk virus Family Carmotetraviridae Family Closteroviridae Family Flaviviridae includes Yellow fever virus West Nile virus Hepatitis C virus Dengue fever virus Zika virus Family Fusariviridae Family Hepeviridae Family Hypoviridae Family Leviviridae Family Luteoviridae includes Barley yellow dwarf virus Family Polycipiviridae Family Narnaviridae Family Nodaviridae Family Permutotetraviridae Family Potyviridae Family Sarthroviridae Family Statovirus Family Togaviridae includes Rubella virus Ross River virus Sindbis virus Chikungunya virus Family Tombusviridae Family Virgaviridae 35 Unassigned genera Genus Blunervirus Genus Cilevirus Genus Higrevirus Genus Idaeovirus Genus Negevirus Genus Ourmiavirus Genus Polemovirus Genus Sinaivirus Genus Sobemovirus Unassigned species Acyrthosiphon pisum virus Bastrovirus Blackford virus Blueberry necrotic ring blotch virus Cadicistrovirus Chara australis virus Extra small virus Goji berry chlorosis virus Harmonia axyridis virus 1 Hepelivirus Jingmen tick virus Le Blanc virus Nedicistrovirus Nesidiocoris tenuis virus 1 Niflavirus Nylanderia fulva virus 1 Orsay virus Osedax japonicus RNA virus 1 Picalivirus Planarian secretory cell nidovirus Plasmopara halstedii virus Rosellinia necatrix fusarivirus 1 Santeuil virus Secalivirus Solenopsis invicta virus 3 Wuhan large pig roundworm virusSatellite viruses Family Sarthroviridae Genus Albetovirus Genus Aumaivirus Genus Papanivirus Genus Virtovirus Chronic bee paralysis virusAn unclassified astrovirus hepevirus like virus has also been described 36 Group V negative sense ssRNA viruses editMain article Negative sense single stranded RNA virus With the exception of the Hepatitis D virus this group of viruses has been placed into a single phylum Negarnaviricota This phylum has been divided into two subphyla Haploviricotina and Polyploviricotina Within the subphylum Haploviricotina four classes are currently recognised Chunqiuviricetes Milneviricetes Monjiviricetes and Yunchangviricetes In the subphylum Polyploviricotina two classes are recognised Ellioviricetes and Insthoviricetes Six classes seven orders and twenty four families are currently recognized in this group A number of unassigned species and genera are yet to be classified 10 Phylum Negarnaviricota 37 Subphylum Haploviricotina Class Chunqiuviricetes Order Muvirales Family Qinviridae Class Milneviricetes Order Serpentovirales Family Aspiviridae Class Monjiviricetes Order Jingchuvirales Family Chuviridae Order Mononegavirales Family Bornaviridae Borna disease virus Family Filoviridae includes Ebola virus Marburg virus Family Mymonaviridae Family Nyamiviridae 38 Family Paramyxoviridae includes Measles virus Mumps virus Nipah virus Hendra virus and NDV Family Pneumoviridae includes RSV and Metapneumovirus Family Rhabdoviridae includes Rabies virus Family Sunviridae Genus Anphevirus Genus Arlivirus Genus Chengtivirus Genus Crustavirus Genus Wastrivirus Class Yunchangviricetes Order Goujianvirales Family Yueviridae Subphylum Polyploviricotina Class Ellioviricetes Order Bunyavirales Family Arenaviridae includes Lassa virus Family Cruliviridae Family Feraviridae Family Fimoviridae Family Hantaviridae Family Jonviridae Family Nairoviridae Family Peribunyaviridae Family Phasmaviridae Family Phenuiviridae Family Tospoviridae Genus Tilapineviridae Class Insthoviricetes Order Articulavirales Family Amnoonviridae includes Taastrup virus Family Orthomyxoviridae includes Influenza viruses Unassigned genera Genus Deltavirus includes Hepatitis D virus not a true virus but a subviral agent Gallery edit nbsp Lassa virus Arenaviridae nbsp Lymphocytic choriomeningitis virus Arenaviridae nbsp Hantavirus Bunyaviridae nbsp Marburg Virus Filoviridae nbsp Ebola virus Filoviridae nbsp Influenza Orthomyxoviridae nbsp Measles Paramyxoviridae nbsp Mumps virus Paramyxoviridae nbsp Human respiratory syncytial virus Paramyxoviridae nbsp Parainfluenza Paramyxoviridae nbsp Rabies Rhabdoviridae nbsp Vesicular stomatitis virus Rhabdoviridae See also edit nbsp Viruses portalVirus classification List of viruses Viral replication Positive negative sense Animal viruses Double stranded RNA viruses Retrovirus DNA viruses Norovirus cis acting replication element ViroidNotes edit This inclusion was due to TaxoProp 2017 006G which proposed Riboviria The confusion might be due to the TaxoProp s reference to a monophyly of all RNA viruses improperly termed as it was only demonstrated with RdRP On the other hand the proposed definition of Riboviria did correctly mention RdRP The majority of fungal viruses are double stranded RNA viruses A small number of positive strand RNA viruses have been described One report has suggested the possibility of a negative stranded virus 8 References edit Wagner Edward K Hewlett Martinez J 1999 Basic virology Malden MA Blackwell Science Inc p 249 ISBN 0 632 04299 0 Retrieved 30 March 2020 a b Patton JT ed 2008 Segmented Double stranded RNA Viruses Structure and Molecular Biology Caister Academic Press ISBN 978 1 904455 21 9 Listing in Taxonomic Order Index to ICTV Species Lists Retrieved 11 April 2008 International Committee on Taxonomy of Viruses Executive Committee May 2020 The new scope of virus taxonomy partitioning the virosphere into 15 hierarchical ranks Nature Microbiology 5 5 668 674 doi 10 1038 s41564 020 0709 x PMC 7186216 PMID 32341570 TaxoProp 2019 006G TaxoProp 2019 009G Nguyen M Haenni AL June 2003 Expression strategies of ambisense viruses Virus Research 93 2 141 50 doi 10 1016 S0168 1702 03 00094 7 PMID 12782362 Kondo H Chiba S Toyoda K Suzuki N January 2013 Evidence for negative strand RNA virus infection in fungi Virology 435 2 201 09 doi 10 1016 j virol 2012 10 002 PMID 23099204 Sanjuan R Nebot MR Chirico N Mansky LM Belshaw R October 2010 Viral mutation rates Journal of Virology 84 19 9733 48 doi 10 1128 JVI 00694 10 PMC 2937809 PMID 20660197 a b c Klein DW Prescott LM Harley J 1993 Microbiology Dubuque Iowa Wm C Brown ISBN 978 0 697 01372 9 Steinhauer DA Holland JJ 1987 Rapid evolution of RNA viruses Annual Review of Microbiology 41 409 33 doi 10 1146 annurev mi 41 100187 002205 PMID 3318675 Boutwell CL Rolland MM Herbeck JT Mullins JI Allen TM October 2010 Viral evolution and escape during acute HIV 1 infection The Journal of Infectious Diseases 202 Suppl 2 S309 14 doi 10 1086 655653 PMC 2945609 PMID 20846038 Bukh J Purcell RH Miller RH August 1994 Sequence analysis of the core gene of 14 hepatitis C virus genotypes Proceedings of the National Academy of Sciences of the United States of America 91 17 8239 43 Bibcode 1994PNAS 91 8239B doi 10 1073 pnas 91 17 8239 PMC 44581 PMID 8058787 Tuplin A Evans DJ Simmonds P October 2004 Detailed mapping of RNA secondary structures in core and NS5B encoding region sequences of hepatitis C virus by RNase cleavage and novel bioinformatic prediction methods The Journal of General Virology 85 Pt 10 3037 47 doi 10 1099 vir 0 80141 0 PMID 15448367 a b Silva JM Pratas D Caetano T Matos D August 2022 The complexity landscape of viral genomes GigaScience 11 1 16 doi 10 1093 gigascience giac079 PMC 9366995 PMID 35950839 a b Barr JN Fearns R June 2010 How RNA viruses maintain their genome integrity The Journal of General Virology 91 Pt 6 1373 87 doi 10 1099 vir 0 020818 0 PMID 20335491 Stedman Kenneth M 2015 Deep Recombination RNA and ssDNA Virus Genes in DNA Virus and Host Genomes Annual Review of Virology 2 1 203 217 doi 10 1146 annurev virology 100114 055127 ISSN 2327 0578 PMID 26958913 S2CID 207745438 Muslin C Mac Kain A Bessaud M Blondel B Delpeyroux F September 2019 Recombination in Enteroviruses a Multi Step Modular Evolutionary Process Viruses 11 9 859 doi 10 3390 v11090859 PMC 6784155 PMID 31540135 Hu WS Temin HM November 1990 Retroviral recombination and reverse transcription Science 250 4985 1227 33 Bibcode 1990Sci 250 1227H doi 10 1126 science 1700865 PMID 1700865 Rawson JM Nikolaitchik OA Keele BF Pathak VK Hu WS November 2018 Recombination is required for efficient HIV 1 replication and the maintenance of viral genome integrity Nucleic Acids Research 46 20 10535 45 doi 10 1093 nar gky910 PMC 6237782 PMID 30307534 a b Bernstein H Bernstein C Michod RE January 2018 Sex in microbial pathogens Infection Genetics and Evolution 57 8 25 doi 10 1016 j meegid 2017 10 024 PMID 29111273 a b Su S Wong G Shi W Liu J Lai AC Zhou J et al June 2016 Epidemiology Genetic Recombination and Pathogenesis of Coronaviruses Trends in Microbiology 24 6 490 502 doi 10 1016 j tim 2016 03 003 PMC 7125511 PMID 27012512 Wolf YI Kazlauskas D Iranzo J Lucia Sanz A Kuhn JH Krupovic M Dolja VV Koonin EV November 2018 Origins and Evolution of the Global RNA Virome mBio 9 6 doi 10 1128 mBio 02329 18 PMC 6282212 PMID 30482837 Francki RI Fauquet CM Knudson DL Brown F 1991 Classification and nomenclature of viruses Fifth report of the International Committee on Taxonomy of Viruses Archives of Virology Suppl 2 Springer ISBN 978 3 7091 9163 7 Current ICTV Taxonomy Release ICTV ictv global Retrieved 3 April 2023 Koonin EV September 1991 The phylogeny of RNA dependent RNA polymerases of positive strand RNA viruses The Journal of General Virology 72 Pt 9 2197 206 doi 10 1099 0022 1317 72 9 2197 PMID 1895057 Rozanov MN Koonin EV Gorbalenya AE August 1992 Conservation of the putative methyltransferase domain a hallmark of the Sindbis like supergroup of positive strand RNA viruses The Journal of General Virology 73 Pt 8 2129 34 CiteSeerX 10 1 1 532 7367 doi 10 1099 0022 1317 73 8 2129 PMID 1645151 Koonin EV Dolja VV 1993 Evolution and taxonomy of positive strand RNA viruses implications of comparative analysis of amino acid sequences Critical Reviews in Biochemistry and Molecular Biology 28 5 375 430 doi 10 3109 10409239309078440 PMID 8269709 Ward CW 1993 Progress towards a higher taxonomy of viruses Research in Virology 144 6 419 53 doi 10 1016 S0923 2516 06 80059 2 PMC 7135741 PMID 8140287 Koonin EV Wolf YI Nagasaki K Dolja VV December 2008 The Big Bang of picorna like virus evolution antedates the radiation of eukaryotic supergroups Nature Reviews Microbiology 6 12 925 39 doi 10 1038 nrmicro2030 PMID 18997823 a b Ghabrial SA 1998 Origin adaptation and evolutionary pathways of fungal viruses Virus Genes 16 1 119 31 doi 10 1023 a 1007966229595 PMC 7089520 PMID 9562896 Gibrat JF Mariadassou M Boudinot P Delmas B July 2013 Analyses of the radiation of birnaviruses from diverse host phyla and of their evolutionary affinities with other double stranded RNA and positive strand RNA viruses using robust structure based multiple sequence alignments and advanced phylogenetic methods BMC Evolutionary Biology 13 154 doi 10 1186 1471 2148 13 154 PMC 3724706 PMID 23865988 Li CX Shi M Tian JH Lin XD Kang YJ Chen LJ et al January 2015 Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative sense RNA viruses eLife 4 doi 10 7554 eLife 05378 PMC 4384744 PMID 25633976 Krupovic M Kuhn JH Fischer MG January 2016 A classification system for virophages and satellite viruses Archives of Virology 161 1 233 47 doi 10 1007 s00705 015 2622 9 hdl 11858 00 001M 0000 0028 DC34 F PMID 26446887 Adams MJ Antoniw JF Kreuze J 2009 Virgaviridae a new family of rod shaped plant viruses Archives of Virology 154 12 1967 72 doi 10 1007 s00705 009 0506 6 PMID 19862474 Pankovics P Boros A Kiss T Engelmann P Reuter G 2019 Genetically highly divergent RNA virus with astrovirus like 5 end and hepevirus like 3 end genome organization in carnivorous birds European roller Coracias garrulus Infect Genet Evol Virus Taxonomy 2018 Release International Committee on Taxonomy of Viruses Retrieved 13 November 2018 Mihindukulasuriya KA Nguyen NL Wu G Huang HV da Rosa AP Popov VL et al May 2009 Nyamanini and midway viruses define a novel taxon of RNA viruses in the order Mononegavirales Journal of Virology 83 10 5109 16 doi 10 1128 JVI 02667 08 PMC 2682064 PMID 19279111 External links editRNA Viruses at the U S National Library of Medicine Medical Subject Headings MeSH Animal viruses Retrieved from https en wikipedia org w index php title RNA virus amp oldid 1201979068, wikipedia, wiki, book, books, library,

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