Virus classification is the process of naming viruses and placing them into a taxonomic system similar to the classification systems used for cellular organisms.
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
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 cysto derives from Greek kystis which means bladder or sack. There are seven species in this genus.
Metaviridae is a family of viruses which exist as Ty3-gypsy LTR retrotransposons in a eukaryotic host's genome. They are closely related to retroviruses: members of the family Metaviridae share many genomic elements with retroviruses, including length, organization, and genes themselves. This includes genes that encode reverse transcriptase, integrase, and capsid proteins. The reverse transcriptase and integrase proteins are needed for the retrotransposon activity of the virus. In some cases, virus-like particles can be formed from capsid proteins.
Pseudoviridae is a family of viruses, which includes three genera.
Tombusviridae is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from Tomato bushy stunt virus (TBSV).
Tobamovirus is a genus of positive-strand RNA viruses in the family Virgaviridae. Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name Tobamovirus comes from the host and symptoms of the first virus discovered.
Tobacco virtovirus 1, informally called Tobacco mosaic satellite virus, Satellite tobacco mosaic virus (STMV), or tobacco mosaic satellite virus, is a satellite virus first reported in Nicotiana glauca from southern California, U.S.. Its genome consists of linear positive-sense single-stranded RNA.
Nepovirus is a genus of viruses in the order Picornavirales, in the family Secoviridae, in the subfamily Comovirinae. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera in the subfamily Comovirinae, are transmitted by nematodes.
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 study found that 72% of Stenotaphrum secundatum infected with panicum mosaic virus was also infected with SPMV. In addition to SPMV, many plants infected with panicum mosaic virus are also infected with satellite RNAs.
Benyvirus is a genus of viruses, in the family Benyviridae. Plant serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: BNYVV: rhizomania.
Corticovirus is a genus of viruses in the family Corticoviridae. Corticoviruses are bacteriophages; that is, their natural hosts are bacteria. The genus contains two species. The name is derived from Latin cortex, corticis. However, prophages closely related to PM2 are abundant in the genomes of aquatic bacteria, suggesting that the ecological importance of corticoviruses might be underestimated. Bacteriophage PM2 was first described in 1968 after isolation from seawater sampled from the coast of Chile.
Carlavirus, formerly known as the "Carnation latent virus group", is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are 53 species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.
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 is a monotypic taxon containing only one genus, Ophiovirus. Aspiviridae is also the only family in the order Serpentovirales, which in turn is the only order in the class Milneviricetes.
Bicaudaviridae is a family of hyperthermophilic archaeal viruses. Members of the genus Acidianus serve as natural hosts. There is only one genus (Bicaudavirus) and one species in this family: Acidianus two-tailed virus. However, Sulfolobus tengchongensis spindle-shaped viruses 1 and 2 are regarded to belong to this family also.
Betanecrovirus is a genus of viruses, in the family Tombusviridae. Plants serve as natural hosts. There are three species in this genus.
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 and class Yunchangviricetes. Two species are recognized: Beihai yuyuevirus and Shahe yuyuevirus.
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 that encode an RNA-dependent DNA polymerase. RNA-dependent RNA polymerase (RdRp), also called RNA replicase, produces RNA from RNA. RNA-dependent DNA polymerase (RdDp), also called reverse transcriptase (RT), produces DNA from RNA. These enzymes are essential for replicating the viral genome and transcribing viral genes into messenger RNA (mRNA) for translation of viral proteins.
Tolivirales is an order of RNA viruses which infect insects and plants. Member viruses have a positive-sense single-stranded RNA genome. The virions are non-enveloped, spherical, and have an icosahedral capsid. The name of the group is a syllabic abbreviation of "tombusvirus-like" with the suffix -virales indicating a virus order.
Maize white line mosaic satellite virus is a plant satellite virus. It is the only species in genus Aumaivirus, which is a member of realm Riboviria without assigned family or order. It only infects maize which is infected by Maize white line mosaic virus (MWLMV) of genus Aureusvirus.
