An RNA virus is a

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

other than a

retrovirus A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. Once inside the host cell's cytoplasm, the virus uses its own reverse transcriptas ...

that has ribonucleic acid ( RNA) as its genetic material. The nucleic acid is usually single-stranded RNA (

ssRNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohyd ...

) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses include the common cold, influenza, SARS, MERS,

Covid-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quick ...

, Dengue Virus,

hepatitis C Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection people often have mild or no symptoms. Occasionally a fever, dark urine, ...

, hepatitis E, West Nile fever, Ebola virus disease,

rabies Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...

polio Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe sy ...

, mumps, and

measles Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...

. 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

es, 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 ''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 ...

''. The majority of such RNA viruses fall into the kingdom ''

Orthornavirae ''Orthornavirae'' is a kingdom of viruses that have genomes made of ribonucleic acid (RNA), those genomes encoding an RNA-dependent RNA polymerase (RdRp). The RdRp is used to transcribe the viral RNA genome into messenger RNA (mRNA) and to repli ...

'' and the rest have a positioning not yet defined.TaxoPro
2019.006G
/ref> The realm does not contain all RNA viruses: '' Deltavirus'', '' Asunviroidae'', and '' Pospiviroidae'' are taxa of RNA viruses that were mistakenly included in 2019, but corrected in 2020.

Characteristics

Single-stranded RNA viruses and RNA Sense

RNA viruses can be further classified according to the sense or polarity of their RNA into

negative-sense In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, ...

and positive-sense, or ambisense RNA viruses. Positive-sense viral RNA is similar to

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the ...

and thus can be immediately

translated Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a terminological distinction (which does not exist in every language) between ''transla ...

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.

Double-stranded RNA viruses

The double-stranded (ds)RNA viruses represent a diverse group of viruses that vary widely in host range (humans, animals, plants,

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

, and

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...

segment number (one to twelve), and virion organization (

Triangulation number A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or ...

, capsid layers, spikes, turrets, etc.). Members of this group include the rotaviruses, which are the most common cause of

gastroenteritis Gastroenteritis, also known as infectious diarrhea and gastro, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydr ...

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 Bluetongue disease is a noncontagious, insect-borne, viral disease of ruminants, mainly sheep and less frequently cattle, yaks, goats, buffalo, deer, dromedaries, and antelope. It is caused by ''Bluetongue virus'' (''BTV''). The virus i ...

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.

Mutation rates

RNA viruses generally have very high

mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, m ...

rates compared to DNA viruses, because viral RNA polymerases lack the proofreading ability of

DNA polymerase A DNA polymerase is a member of a family of enzymes that catalyze the synthesis of DNA molecules from nucleoside triphosphates, the molecular precursors of DNA. These enzymes are essential for DNA replication and usually work in groups to crea ...

s. The genetic diversity of RNA viruses is one reason why it is difficult to make effective

vaccines A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.

against them. 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. 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 In evolutionary biology, conserved sequences are identical or similar sequences in nucleic acids ( DNA and RNA) or proteins across species ( orthologous sequences), or within a genome ( paralogous sequences), or between donor and receptor taxa ( ...

, because it contains an RNA structure involved in an internal ribosome entry site.

Sequence complexity

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. The sequence complexity of viruses has been shown to be a key characteristic for accurate reference-free viral classification.

Replication

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.

Retrovirus A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. Once inside the host cell's cytoplasm, the virus uses its own reverse transcriptas ...

es (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

Numerous RNA viruses are capable of

genetic recombination Genetic recombination (also known as genetic reshuffling) is the exchange of genetic material between different organisms which leads to production of offspring with combinations of traits that differ from those found in either parent. In eukaryo ...

when at least two viral

s are present in the same host cell. Very rarely viral RNA can recombine with host RNA. RNA recombination appears to be a major driving force in determining genome architecture and the course of viral evolution among ''

Picornaviridae Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 ...

'' ( (+)ssRNA), e.g.

poliovirus A poliovirus, the causative agent of polio (also known as poliomyelitis), is a serotype of the species '' Enterovirus C'', in the family of '' Picornaviridae''. There are three poliovirus serotypes: types 1, 2, and 3. Poliovirus is composed of ...

. 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. Recombination also occurs in the '' Reoviridae'' (dsRNA), e.g. reovirus; '' Orthomyxoviridae'' ((-)ssRNA), e.g. influenza virus; and '' Coronaviridae'' ((+)ssRNA), e.g. SARS. Recombination in RNA viruses appears to be an adaptation for coping with genome damage. 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.

Classification

Classification of the RNA viruses is difficult. This is in part due to the high mutation rates these genomes undergo. 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. 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

This is the single largest group of RNA viruses with 30 families. Attempts have been made to group these families in higher orders. These proposals were based on an analysis of the RNA polymerases and are still under consideration. To date, the suggestions proposed have not been broadly accepted because of doubts over the suitability of a single gene to determine the taxonomy of the clade. The proposed classification of positive-strand RNA viruses is based on the RNA-dependent RNA polymerase. Three groups have been recognised: # 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. 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 A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English te ...

: the rubi-like, tobamo-like, and tymo-like viruses. Additional work has identified five groups of positive-stranded RNA viruses containing four, three, three, three, and one order(s), respectively. 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

The evolution of the picornaviruses based on an analysis of their RNA polymerases and helicases appears to date to the divergence of

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacter ...

s. Their putative ancestors include the bacterial group II

retroelement Retrotransposons (also called Class I transposable elements or transposons via RNA intermediates) are a type of genetic component that copy and paste themselves into different genomic locations ( transposon) by converting RNA back into DNA throug ...

s, the family of HtrA

protease A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...

s and DNA

bacteriophage A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bac ...

s. Partitiviruses are related to and may have evolved from a totivirus ancestor. Hypoviruses and barnaviruses appear to share an ancestry with the potyvirus and sobemovirus lineages respectively.

Double-stranded RNA viruses

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''.

Negative strand RNA viruses

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

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

s and to have diversified from there.

Satellite viruses

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 ''Albetovirus'' is a plant satellite virus genus. As a member of realm ''Riboviria'' without assigned family or order it contains just three species, ''Tobacco albetovirus 1'', ''2'', and ''3'' (alias Satellite tobacco necrosis virus 1, 2, respec ...

Aumaivirus Maize white line mosaic satellite virus (syn. Satellite maize white line mosaic virus, Satellite virus of maize white line mosaic virus, SMWLMV, SV-MWLMV) is a plant satellite virus. It is the only species in genus ''Aumaivirus'', which is a mem ...

Papanivirus Panicum mosaic satellite virus (SPMV) is a plant satellite virus in genus ''Papanivirus'', which is a member of realm ''Riboviria'' without assigned family or order. It only infects grasses which are infected by ''Panicum mosaic virus''. One st ...

and Virtovirus. A family— Sarthroviridae which includes the genus Macronovirus—has been proposed for the positive sense single stranded RNA satellite viruses that infect

Group III – dsRNA viruses

There are twelve families and a number of unassigned genera and species recognised in this group. * Family

Amalgaviridae ''Amalgaviridae'' is a family of double-stranded RNA viruses. Member viruses infect plants and are transmitted vertically via seeds. The name derives from ''amalgam'' (blend, mix) which refers to amalgaviruses possessing characteristics of both ...

* Family Birnaviridae * Family

Chrysoviridae ''Chrysoviridae'' is a family of double-stranded RNA viruses Double-stranded RNA viruses (dsRNA viruses) are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to ...

* Family

Cystoviridae ''Cystovirus'' is a genus of double-stranded RNA viruses which infects bacteria. It is the only genus in the family ''Cystoviridae.'' The name of the group c''ysto'' derives from Greek ''kystis'' which means bladder or sack. There are seven sp ...

* Family

Endornaviridae ''Endornaviridae'' is a family of viruses. Plants, fungi, and oomycetes serve as natural hosts. There are 31 species in this family, assigned to 2 genera (''Alphaendornavirus'' and ''Betaendornavirus''). Members of ''Alphaendornavirus'' infect ...

* Family

Hypoviridae ''Hypovirus'' is a genus of viruses, in the family ''Hypoviridae''. Fungi serve as natural hosts. There are four species in this genus. Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control. ...

* Family

Megabirnaviridae ''Megabirnaviridae'' is a family of double-stranded RNA viruses with one genus ''Megabirnavirus'' which infects fungi. The group name derives from member's ''bi''partite ds''RNA'' genome and ''mega'' that is greater genome size (16 kbp) than f ...

* Family Partitiviridae * Family

Picobirnaviridae ''Picobirnavirus'' is a genus of double-stranded RNA viruses. It is the only genus in the family ''Picobirnaviridae''. Although amniotes, especially mammals, were thought to serve as hosts, it has been recently suggested that these viruses migh ...

* Family Reoviridae – includes Rotavirus * Family Totiviridae * Family

Quadriviridae ''Quadriviridae'' is a family of double-stranded RNA viruses with a single genus ''Quadrivirus''. The fungi ''Rosellinia necatrix'' serves as a natural host. The name of the group derives from the ''quadri''partite genome of its members where ...

* Genus Botybirnavirus * Unassigned species ** ''

Botrytis porri RNA virus 1 Botrytis may refer to: *Botrytis (fungus), ''Botrytis'' (fungus), the anamorphs of fungi of the genus ''Botryotinia'' **''Botrytis cinerea'', a mold important in wine making *Botrytis, the cauliflower cultivar group of ''Brassica oleracea'' {{disam ...

'' ** ''

Circulifer tenellus virus 1 ''Circulifer'' is a genus of leafhoppers in the tribe Opsiini and the subfamily Deltocephalinae. Some authors have treated it as a subgenus of ''Neoaliturus''. Species * ''Circulifer alboflavovittatus'' Lindberg, 1954 * ''Circulifer dubiosus'' (M ...

'' ** ''

Colletotrichum camelliae filamentous virus 1 ''Colletotrichum'' (sexual stage: ''Glomerella'') is a genus of fungi that are symbionts to plants as endophytes (living within the plant) or phytopathogens. Many of the species in this genus are plant pathogens, but some species may have a m ...

'' ** ''

Cucurbit yellows associated virus Cucurbit may refer to:- *A plant of the family Cucurbitaceae *The lower part of an alembic An alembic (from ar, الإنبيق, al-inbīq, originating from grc, ἄμβιξ, ambix, 'cup, beaker') is an alchemical still consisting of two vess ...

'' ** ''

Sclerotinia sclerotiorum debilitation-associated virus ''Sclerotinia'' is a genus of fungi in the family Sclerotiniaceae. The widely distributed genus contains 14 species. Taxonomy A number of species previously assigned to ''Sclerotinia'' are now considered to be members of the closely related genu ...

'' ** '' Spissistilus festinus virus 1''

Group IV – positive-sense ssRNA viruses

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

Nidovirales ''Nidovirales'' is an order of enveloped, positive-strand RNA viruses which infect vertebrates and invertebrates. Host organisms include mammals, birds, reptiles, amphibians, fish, arthropods, molluscs, and helminths. The order includes the ...

** Family Arteriviridae ** Family Coronaviridae – includes

Human coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the comm ...

(common cold viruses HCoV-229E, HCoV-HKU1, HCoV-NL63, and

HCoV-OC43 Human coronavirus OC43 (HCoV-OC43) is a member of the species ''Betacoronavirus 1'', which infects humans and cattle. The infecting coronavirus is an enveloped, positive-sense, single-stranded RNA virus that enters its host cell by binding to t ...

), MERS-CoV,

SARS-CoV-1 Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1; or Severe acute respiratory syndrome coronavirus, SARS-CoV) is a strain of coronavirus that causes severe acute respiratory syndrome (SARS), the respiratory illness responsible for t ...

and

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...

** Family Mesoniviridae ** Family

Roniviridae ''Okavirus'' is a genus of enveloped positive-strand RNA viruses which infect crustaceans. Host organisms are mostly shrimp. It is the only genus in the family ''Roniviridae''. Viruses associated with the genus include: gill-associated virus ( ...

* Order

Picornavirales ''Picornavirales'' is an order of viruses with vertebrate, invertebrate, protist and plant hosts. The name has a dual etymology. First, ''picorna-'' is an acronym for poliovirus, insensitivity to ether, coxsackievirus, orphan virus, rhinov ...

** Family Dicistroviridae ** Family Iflaviridae ** Family Marnaviridae ** Family

– includes

Poliovirus A poliovirus, the causative agent of polio (also known as poliomyelitis), is a serotype of the species '' Enterovirus C'', in the family of '' Picornaviridae''. There are three poliovirus serotypes: types 1, 2, and 3. Poliovirus is composed of ...

, Rhinovirus (a common cold virus),

Hepatitis A Hepatitis A is an infectious disease of the liver caused by ''Hepatovirus A'' (HAV); it is a type of viral hepatitis. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop the ...

virus ** Family

Secoviridae ''Secoviridae'' is a family of viruses in the order ''Picornavirales''. Plants serve as natural hosts. There are 8 genera and 86 species in this family, one of which is unassigned to a genus. The family was created in 2009 with the grouping of ...

includes subfamily Comovirinae ** Genus Bacillariornavirus ** Species

Kelp fly virus Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwa ...

* Order

Tymovirales ''Tymovirales'' is an order of viruses with five families. The group consists of viruses which have positive-sense, single-stranded RNA genomes. Their genetic material is protected by a special coat protein. Description Tymoviruses are mainly ...

** Family Alphaflexiviridae ** Family Betaflexiviridae ** Family Gammaflexiviridae ** Family

Tymoviridae ''Tymoviridae'' is a family of single-stranded positive sense RNA viruses in the order '' Tymovirales''. Plants serve as natural hosts. There are 42 species in this family, assigned to three genera, with two species unassigned to a genus. Tax ...

* Unassigned ** Family Alphatetraviridae ** Family

Alvernaviridae ''Alvernaviridae'' is a family of non-enveloped positive-strand RNA viruses. Dinoflagellates serve as natural hosts. There is one genus in this family, ''Dinornavirus'', which contains one species: ''Heterocapsa circularisquama RNA virus 01''. ...

** Family Astroviridae ** Family

Barnaviridae ''Barnaviridae'' is a family of non-enveloped, positive-strand RNA viruses. Cultivated mushrooms serve as natural hosts. The family has one genus, ''Barnavirus'', which contains one species: ''Mushroom bacilliform virus''. Diseases associated wi ...

** Family Benyviridae ** Family

Botourmiaviridae ''Botourmiaviridae'' is a family of positive-strand RNA viruses which infect plants and fungi. The family includes four genera: '' Ourmiavirus'', ''Botoulivirus'', ''Magoulivirus'' and ''Scleroulivirus''. Members of genus ''Ourmiavirus'' infec ...

** Family Bromoviridae ** Family

Caliciviridae The ''Caliciviridae'' are a family of "small round structured" viruses, members of Class IV of the Baltimore scheme. Caliciviridae bear resemblance to enlarged picornavirus and was formerly a separate genus within the picornaviridae. They are p ...

– includes Norwalk virus ** Family

Carmotetraviridae ''Carmotetraviridae'' is a family of positive-strand RNA viruses. There is only one genus in this family, ''Alphacarmotetravirus'', which has one species: ''Providence virus''. Lepidopteran insects serve as natural hosts. Structure Viruses in ' ...

** Family

Closteroviridae ''Closteroviridae'' is a family of viruses. Plants serve as natural hosts. There are four genera and 59 species in this family, seven of which are unassigned to a genus. Diseases associated with this family include: yellowing and necrosis, part ...

** Family Flaviviridae – includes

Yellow fever Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains – particularly in the back – and headaches. Symptoms typically improve within five days. ...

virus, West Nile virus, Hepatitis C virus, Dengue fever virus, Zika virus ** Family Fusariviridae ** Family Hepeviridae ** Family

** Family Leviviridae ** Family

Luteoviridae ''Luteoviridae'' was a family of viruses. The family was abolished in 2020 based on evidence that its three genera and seven species unassigned to a genus belonged to two other, existing families. * The genus '' Enamovirus'' was reassigned to t ...

– includes Barley yellow dwarf virus ** Family Polycipiviridae ** Family Narnaviridae ** Family

Nodaviridae ''Nodaviridae'' is a family of nonenveloped positive-strand RNA viruses. Vertebrates and invertebrates serve as natural hosts. Diseases associated with this family include: viral encephalopathy and retinopathy in fish. There are nine species in ...

** Family Permutotetraviridae ** Family Potyviridae ** Family Sarthroviridae ** Family Statovirus ** Family Togaviridae – includes Rubella virus, Ross River virus, Sindbis virus, Chikungunya virus ** Family Tombusviridae ** Family

Virgaviridae ''Virgaviridae'' is a family of positive-strand RNA viruses. Plants serve as natural hosts.Adams MJ, Antoniw JF, Kreuze J (2009) Virgaviridae: a new family of rod-shaped plant viruses. Arch Virol 154(12):1967–1972 The name of the family is der ...

** Unassigned genera *** Genus '' Blunervirus'' *** Genus ''

Cilevirus ''Cilevirus'' is a genus of viruses in the family '' Kitaviridae''. Plants serve as natural hosts. There are two species: '' Citrus leprosis virus C'' and '' Citrus leprosis virus C2''. History This genus was created in 2006 by Locali-Fabris ' ...

'' *** Genus ''

Higrevirus ''Higrevirus'' is a genus of viruses. Plants serve as natural hosts. There is currently only one species in this genus: the type species ''Hibiscus green spot virus 2''. Structure Viruses in Higrevirus are non-enveloped, with bacilliform geome ...

'' *** Genus ''

Idaeovirus ''Idaeovirus'' is a genus of positive-sense ssRNA viruses that contains two species: ''Raspberry bushy dwarf virus'' (RBDV) and ''Privet idaeovirus''. RBDV has two host-dependent clades: one for raspberries; the other for grapevines. Infections ...

'' *** Genus ''

Negevirus ''Negevirus'' is a taxon of non segmented, positive sense single stranded RNA viruses that have been isolated from mosquitoes and phlebotomine sand flies in Africa, the Americas, Asia and Europe.Nunes MRT, Contreras-Gutierrez MA, Guzman H, M ...

'' *** Genus ''

Ourmiavirus ''Ourmiavirus'' is a genus of positive-strand RNA viruses. Cucurbits, cherry, and cassava ''Manihot esculenta'', commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbi ...

'' *** Genus ''

Polemovirus ''Polemovirus'' is a genus of viruses. Commercial cultivars of ''Euphorbia pulcherrima'' serve as natural hosts. There is only one species in this genus: ''Poinsettia latent virus''. Its RNA suggests a replication mode like that of polerovir ...

'' *** Genus '' Sinaivirus'' *** Genus ''

Sobemovirus ''Sobemovirus'' is a genus of viruses. Plants serve as natural hosts. There are 20 species in this genus. Diseases associated with this genus include: mosaics and mottles. Structure Viruses in ''Sobemovirus'' are non-enveloped, with icosahed ...

'' ** Unassigned species ***

Acyrthosiphon pisum virus ''Acyrthosiphon'' is a genus of aphids belonging to the family Aphididae. The genus was described in 1914 by Alexander Mordvilko. The genus has cosmopolitan distribution. Species These species belong to the genus ''Acyrthosiphon'': * '' Acyr ...

*** Bastrovirus ***

Blackford virus Blackford might refer to: People with the surname * Charles Minor Blackford (1833–1903), an American lawyer *Hosea Blackford, a fictional character in books by Harry Turtledove *Ian Blackford, a Scottish politician *Isaac Blackford (1786–1859) ...

***

Blueberry necrotic ring blotch virus Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' within the genus '' Vaccinium''. ''Vaccinium'' also includes cranberries ...

*** Cadicistrovirus *** Chara australis virus ***

Extra small virus Extra or Xtra may refer to: Arts, entertainment and media Film * ''The Extra'' (1962 film), a Mexican film * ''The Extra'' (2005 film), an Australian film Literature * ''Extra'' (newspaper), a Brazilian newspaper * ''Extra!'', an American me ...

***

Goji berry chlorosis virus Goji, goji berry, or wolfberry () is the fruit of either ''Lycium barbarum'' or ''Lycium chinense'', two closely related species of boxthorn in the nightshade family, Solanaceae. ''L. barbarum'' and ''L. chinense'' fruits are simil ...

***

Harmonia axyridis virus 1 In Greek mythology, Harmonia (; grc, Ἁρμονία / harmoˈnia/, "harmony", "agreement") is the immortal goddess of harmony and concord. Her Roman counterpart is Concordia. Her Greek opposite is Eris, whose Roman counterpart is Discor ...

*** Hepelivirus ***

Jingmen tick virus Jingmen () is a prefecture-level city in central Hubei province, People's Republic of China. Jingmen is within an area where cotton and oil crops are planted. The population of the prefecture is 2,873,687 (2010 population census). The urban area ...

*** Le Blanc virus *** Nedicistrovirus *** Nesidiocoris tenuis virus 1 *** Niflavirus ***

Nylanderia fulva virus 1 ''Nylanderia'' is a large genus of ants in the subfamily Formicinae. The genus has a nearly cosmopolitan distribution with species inhabiting a wide array of habitats in almost all geographic regions. ''Nylanderia'', currently containing ove ...

***

Orsay virus Orsay virus is a positive-sense single-stranded RNA virus that infects ''Caenorhabditis elegans'' nematode. It resembles nodaviruses (family ''Nodaviridae''), but has yet to be formally classified. Orsay virus has a (+)ssRNA genome consisting o ...

***

Osedax japonicus RNA virus 1 ''Osedax'' is a genus of deep-sea siboglinid polychaetes, commonly called boneworms, zombie worms, or bone-eating worms. ''Osedax'' is Latin for "bone-eater". The name alludes to how the worms bore into the bones of whale carcasses to reach ...

*** Picalivirus ***

Planarian secretory cell nidovirus Planarian secretory cell nidovirus (PSCNV) is a virus of the species ''Planidovirus 1'', a nidovirus notable for its extremely large genome. At 41.1 kilobases, it is the largest known genome of an RNA virus. It was discovered by inspecting the ...

***

Plasmopara halstedii virus ''Plasmopara'' is a genus of Oomycota. ''Plasmopara'' species are Phytopathology, plant pathogens, causing downy mildew on carrot, parsley, parsnip, chervil, and impatiens. References Further reading * * * External links

* Water mould ...

***

Rosellinia necatrix fusarivirus 1 ''Rosellinia'' is a genus of fungi in the family Xylariaceae consisting of over 90 species. Several of the species in this genus are plant pathogens. Fossils of ''Rosellinia'' have been found in 12 million year old rocks from central England. T ...

***

Santeuil virus Santeuil may refer to the following places in France: * Santeuil, Eure-et-Loir, a commune in the Eure-et-Loir department * Santeuil, Val-d'Oise, a commune in the Val-d'Oise department {{Geodis ...

*** Secalivirus ***

Solenopsis invicta virus 3 ''Solenopsis'' is a scientific name for two genera: * Solenopsis (ant), ''Solenopsis'' (ant), a genus of ants * Solenopsis (plant), ''Solenopsis'' (plant), a genus of flowering plants in the family Campanulaceae, commonly treated as a synonym of ''L ...

***

Wuhan large pig roundworm virus Wuhan (, ; ; ) is the capital of Hubei Province in the People's Republic of China. It is the largest city in Hubei and the most populous city in Central China, with a population of over eleven million, the ninth-most populous Chinese city an ...

Satellite viruses * Family Sarthroviridae * Genus

* Genus

* Genus Virtovirus *

Chronic bee paralysis virus Chronic bee paralysis virus (CBPV) commonly affects adult ''Apis mellifera'' honey bees and causes a chronic paralysis that can easily spread to other members of a colony. Bees infected with CBPV begin to show symptoms after 5 days and die a few ...

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

Group V – negative-sense ssRNA viruses

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 ''Haploviricotina'' is a subphylum of viruses in the phylum ''Negarnaviricota''. It is one of only two virus subphyla, the other being ''Polyploviricotina'', which is also in ''Negarnaviricota''. The name comes from , the Ancient Greek for 's ...

and Polyploviricotina. Within the subphylum Haploviricotina four classes are currently recognised:

Chunqiuviricetes ''Yingvirus'' is a genus of negative-strand RNA viruses which infect invertebrates. Member viruses have bisegmented genomes. It is the only genus in the family ''Qinviridae'', which is the only family in ''Muvirales'', which is the only order in ...

Milneviricetes ''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It ...

, Monjiviricetes and

Yunchangviricetes ''Yuyuevirus'' is a genus of negative-strand RNA viruses which infect invertebrates. Member viruses have bisegmented genomes. It is the only genus in the family ''Yueviridae'', which in turn is the only family in the order ''Goujianvirales'' an ...

. In the subphylum Polyploviricotina two classes are recognised: Ellioviricetes and

Insthoviricetes ''Articulavirales'' is an order of segmented negative-strand RNA viruses which infect invertebrates and vertebrates. It includes the family of influenza viruses which infect humans. It is the only order of viruses in the monotypic class ''In ...

. 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. * Phylum '' Negarnaviricota'' ** Subphylum ''

'' *** Class ''

'' **** Order ''

Muvirales ''Yingvirus'' is a genus of negative-strand RNA viruses which infect invertebrates. Member viruses have bisegmented genomes. It is the only genus in the family ''Qinviridae'', which is the only family in ''Muvirales'', which is the only order in ...

'' ***** Family ''

Qinviridae ''Yingvirus'' is a genus of negative-strand RNA viruses which infect invertebrates. Member viruses have bisegmented genomes. It is the only genus in the family ''Qinviridae'', which is the only family in ''Muvirales'', which is the only order in ...

'' *** Class ''

'' **** Order ''

Serpentovirales ''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It ...

'' ***** Family ''

Aspiviridae ''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It i ...

'' *** Class '' Monjiviricetes'' **** Order ''

Jingchuvirales ''Jingchuvirales'' is an order of virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bac ...

'' ***** Family ''

Chuviridae ''Chuviridae'' is a family of virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria ...

'' **** Order '' Mononegavirales'' ***** Family ''

Bornaviridae ''Bornaviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Horses, sheep, cattle, rodents, birds, reptiles, and humans serve as natural hosts. Diseases associated with bornaviruses include Borna disease, a fata ...

'' –

Borna disease virus The Borna disease viruses 1 and 2 (BoDV-1 and BoDV-2) are members of the species ''Mammalian 1 orthobornavirus'' and cause Borna disease in mammals. Virology Genome BoDV-1/2 have the smallest genome (8.9 kilobases) of any ''Mononegavi ...

***** Family '' Filoviridae'' – includes

Ebola Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after becom ...

virus,

Marburg virus Marburg virus (MARV) is a hemorrhagic fever virus of the '' Filoviridae'' family of viruses and a member of the species '' Marburg marburgvirus'', genus '' Marburgvirus''. It causes Marburg virus disease in primates, a form of viral hemorrhagi ...

***** Family ''

Mymonaviridae ''Mymonaviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales'', which infect fungi. Fungi serve as natural hosts. The name is a portmanteau of Ancient Greek ''my''co, which means fungus, and ''mo''noneg''a''viral ...

'' ***** Family ''

Nyamiviridae ''Nyamiviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Ecdysozoa and birds serve as natural hosts. The name is a portmanteau of ''Nya''manini Pan (place of isolation of type species Nyamanini virus in Sout ...

'' ***** Family '' Paramyxoviridae'' – includes

Measles Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...

virus,

Mumps virus The mumps virus (MuV) is the virus that causes mumps. MuV contains a single-stranded, negative-sense genome made of ribonucleic acid (RNA). Its genome is about 15,000 nucleotides in length and contains seven genes that encode nine proteins. The ...

, Nipah virus, Hendra virus, and NDV ***** Family '' Pneumoviridae'' – includes RSV and

Metapneumovirus ''Metapneumovirus'' is a genus of viruses in the family ''Pneumoviridae''. The genus contains two species: * Avian metapneumovirus Avian metapneumovirus (aMPV), also known as turkey rhinotracheitis or swollen head syndrome, causes a variety o ...

***** Family ''

Rhabdoviridae ''Rhabdoviridae'' is a family of negative-strand RNA viruses in the order '' Mononegavirales''. Vertebrates (including mammals and humans), invertebrates, plants, fungi and protozoans serve as natural hosts. Diseases associated with member ...

'' – includes

Rabies Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...

virus ***** Family ''

Sunviridae ''Sunviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales.'' Snakes serve as natural hosts. The family includes the single genus ''Sunshinevirus'' which includes the single species ''Reptile sunshinevirus 1''.The f ...

'' ***** Genus Anphevirus ***** Genus Arlivirus ***** Genus Chengtivirus ***** Genus Crustavirus ***** Genus Wastrivirus *** Class ''

'' **** Order ''

Goujianvirales ''Yuyuevirus'' is a genus of negative-strand RNA viruses which infect invertebrates. Member viruses have bisegmented genomes. It is the only genus in the family ''Yueviridae'', which in turn is the only family in the order ''Goujianvirales'' an ...

'' ***** Family '' Yueviridae'' ** Subphylum '' Polyploviricotina'' *** Class '' Ellioviricetes'' **** Order ''

Bunyavirales ''Bunyavirales'' is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. It is the only order in the class ''Ellioviricetes''. The name ''Bunyav ...

'' ***** Family '' Arenaviridae'' – includes Lassa virus ***** Family ''

Cruliviridae Cruliviridae is a family of virus in the order of Bunyavirales. Unlike other families in the order, this family is unique in the sense that it is only used to contain crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon wh ...

'' ***** Family ''

Feraviridae Phasmaviridae is a family of viruses with negative stranded RNA genomes associated with insect hosts. They are a member of the order ''Bunyavirales''. Phasmaviruses were first discovered in phantom midges of the genus ''Chaoborus'' in 2014. T ...

'' ***** Family '' Fimoviridae'' ***** Family '' Hantaviridae'' ***** Family '' Jonviridae'' ***** Family ''

Nairoviridae ''Nairoviridae'' is a family of viruses in the order ''Bunyavirales ''Bunyavirales'' is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. I ...

'' ***** Family '' Peribunyaviridae'' ***** Family ''

Phasmaviridae Phasmaviridae is a family of viruses with negative stranded RNA genomes associated with insect hosts. They are a member of the order ''Bunyavirales''. Phasmaviruses were first discovered in phantom midges of the genus '' Chaoborus'' in 2014. T ...

'' ***** Family ''

Phenuiviridae ''Phenuiviridae'' is a family of negative-strand RNA viruses in the order '' Bunyavirales''. Ruminants, camels, humans, and mosquitoes serve as natural hosts. Member genus ''Phlebovirus'' is the only genus of the family that has viruses that caus ...

'' ***** Family '' Tospoviridae'' ***** Genus '' Tilapineviridae'' *** Class ''

'' **** Order '' Articulavirales'' ***** Family '' Amnoonviridae'' – includes

Taastrup virus Taastrup () is a Danish railway town or/and suburb of Copenhagen - 15 km west of the capital's city centre, and formerly the administrative seat of Høje-Taastrup Municipality, Region Hovedstaden. It takes its name from the village of Taa ...

***** Family '' Orthomyxoviridae'' – includes Influenza viruses * Unassigned genera: ** Genus '' Deltavirus'' – includes Hepatitis D virus (not a true virus, but a subviral agent)

Gallery

File:Lassa virus.JPG, Lassa virus ('' Arenaviridae'') File:Lymphocytic choriomeningitis virus.jpg, Lymphocytic choriomeningitis virus ('' Arenaviridae'') File:Sin Nombre virus Hanta TEM 1137 lores.jpg, Hantavirus ('' Bunyaviridae'') File:Marburg virus.jpg,

Marburg Virus Marburg virus (MARV) is a hemorrhagic fever virus of the '' Filoviridae'' family of viruses and a member of the species '' Marburg marburgvirus'', genus '' Marburgvirus''. It causes Marburg virus disease in primates, a form of viral hemorrhagi ...

('' Filoviridae'') File:Ebola virions.png, Ebola virus ('' Filoviridae'') File:Influenza virus particle 8430 lores.jpg, Influenza ('' Orthomyxoviridae'') File:Measles virus.JPG,

('' Paramyxoviridae'') File:Mumps virus, negative stained TEM 8758 lores.jpg,

('' Paramyxoviridae'') File:Respiratory Syncytial Virus (RSV) EM PHIL 2175 lores.jpg, Human respiratory syncytial virus ('' Paramyxoviridae'') File:Parainfluenza virus TEM PHIL 271 lores.jpg, Parainfluenza ('' Paramyxoviridae'') File:Rabies Virus EM PHIL 1876.JPG,

(''

'') File:Vesicular stomatitis virus (VSV) EM 18 lores.jpg,

Vesicular stomatitis virus ''Indiana vesiculovirus'', formerly ''Vesicular stomatitis Indiana virus'' (VSIV or VSV) is a virus in the family '' Rhabdoviridae''; the well-known '' Rabies lyssavirus'' belongs to the same family. VSIV can infect insects, cattle, horses and pi ...

(''

'')

Notes

References

External links

*
Animal viruses
{{Authority control RNA

Characteristics

Single-stranded RNA viruses and RNA Sense

Double-stranded RNA viruses

Mutation rates

Sequence complexity

Replication

Recombination

Classification

Positive strand RNA viruses

Evolution

Double-stranded RNA viruses

Negative strand RNA viruses

Satellite viruses

Group III – dsRNA viruses

Group IV – positive-sense ssRNA viruses

Group V – negative-sense ssRNA viruses

Gallery

See also

Notes

References

External links