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Pisuviricota. Pisuviricota est un embranchement de virus à ARN, qui comprend tous les virus à ARN à simple brin à polarité positive et ceux à double brin, qui infectent les eucaryotes, et ne sont pas membres des embranchements des Kitrinoviricota, Lenarviricota ou Duplornaviricota 2 . Le nom du groupe est une abréviation syllabique de ...
Pisuviricota. Pisuviricota is a phylum of RNA viruses that includes all positive-strand and double-stranded RNA viruses that infect eukaryotes and are not members of the phylum Kitrinoviricota, Lenarviricota or Duplornaviricota. [1] The name of the group is a syllabic abbreviation of “ pi cornavirus su pergroup” with the suffix -viricota ...
- Pisuviricota
- Orthornavirae
- Etymology
- Characteristics
- Phylogenetics
- Classification
- Disease
- History
- Gallery
The first part of Orthornavirae comes from Greek ὀρθός [orthós], meaning straight, the middle part, rna, refers to RNA, and -viraeis the suffix used for virus kingdoms.
Structure
RNA viruses in Orthornavirae typically do not encode many proteins, but most positive-sense, single-stranded (+ssRNA) viruses and some double-stranded RNA (dsRNA) viruses encode a major capsid protein that has a single jelly roll fold, so named because the folded structure of the protein contains a structure that resembles a jelly roll. Many also possess an envelope, a type of lipidmembrane that typically surrounds the capsid. In particular, the viral envelope is near-universal among negative...
Genome
Viruses in Orthornavirae have three different types of genomes: dsRNA, +ssRNA, and -ssRNA. Single-stranded RNA viruses have either a positive or negative sense strand, and dsRNA viruses have both. This structure of the genome is important in terms of transcription to synthesize viral mRNA as well as replication of the genome, both of which are carried out by the viral enzyme RNA-dependent RNA polymerase(RdRp), also called RNA replicase.
Evolution
RNA viruses in Orthornavirae experience a high rate of genetic mutations because RdRp is prone to making errors in replication since it typically lacks proofreading mechanisms to repair errors.[note 1] Mutations in RNA viruses are often influenced by host factors such as dsRNA-dependent adenosine deaminases, which edit viral genomes by changing adenosines to inosines. Mutations in genes that are essential for replication lead to a reduced number of progeny, so viral genomes typically contain...
The exact origin of Orthornavirae is not well established, but the viral RdRp shows a relation to the reverse transcriptase (RT) enzymes of group II introns that encode RTs and retrotransposons, the latter of which are self-replicating DNA sequences that integrate themselves into other parts of the same DNA molecule. A larger study (2022) where new...
RNA viruses that encode RdRp are assigned to the kingdom Orthornavirae, which contains five official phyla, six unofficial phylaand several taxa that are unassigned to a phylum due to lack of information. The five phyla are separated based on the genome types, host ranges, and genetic similarity of member viruses. 1. Phylum: Duplornaviricota, which...
RNA viruses are associated with a wide range of disease, including many of the most widely known viral diseases. Notable disease-causing viruses in Orthornaviraeinclude: Animal viruses in Orthornavirae include orbiviruses, which cause various diseases in ruminants and horses, including Bluetongue virus, African horse sickness virus, Equine encephal...
Diseases caused by RNA viruses in Orthornavirae have been known throughout much of history, but their cause was only discovered in modern times. As a whole, RNA viruses were discovered during a time period of major advancements in molecular biology, including the discovery of mRNA as the immediate carrier of genetic information for protein synthesi...
Lassa virus (Arenaviridae)Lymphocytic choriomeningitis virus (Arenaviridae)Hantavirus (Bunyaviridae)Marburg virus (Filoviridae)Pisoniviricetes is a class of positive-strand RNA viruses which infect eukaryotes. [1] [2] A characteristic of the group is a conserved 3C - like protease from the PA clan of proteases for processing the translated polyprotein. [3] [4] [5] The name of the group is a portmanteau of member orders " pi cornavirales, so belivirales, ni dovirales ...
- Pisoniviricetes
- Pisuviricota
Picornaviruses cause a range of diseases. Enteroviruses of the picornavirus family infect the enteric tract, which is reflected in their name. Rhinoviruses infect primarily the nose and the throat. Enteroviruses replicate at 37 °C, whereas rhinoviruses grow better at 33 °C, as this is the lower temperature of the nose.
- Picornaviridae
- Orthornavirae
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. [1] They are positive-sense, single-stranded RNA which is not segmented. [2]
Positive-sense RNA virus. Positive-strand RNA viruses ( +ssRNA viruses) are a group of related viruses that have positive-sense, single-stranded genomes made of ribonucleic acid. The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated into viral proteins by the host cell's ribosomes.
