An RNA virus is a virus—other than a retrovirus—that has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA (ssRNA) but it may be double-stranded (dsRNA). 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.
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 common cold, while more lethal varieties can cause SARS, MERS and COVID-19, which is causing the ongoing pandemic. In cows and pigs they cause diarrhea, while in mice they cause hepatitis and encephalomyelitis.
Severe acute respiratory syndrome–related coronavirus is a species of virus consisting of many known strains phylogenetically related to severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) that have been shown to possess the capability to infect humans, bats, and certain other mammals. These enveloped, positive-sense single-stranded RNA viruses enter host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. The SARSr-CoV species is a member of the genus Betacoronavirus and of the subgenus Sarbecovirus.
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 genome is encased by a capsid that is in turn surrounded by a viral envelope. MuV particles, called virions, are pleomorphic in shape and vary in size from 100 to 600 nanometers in diameter. One serotype and twelve genotypes that vary in their geographic distribution are recognized. Humans are the only natural host of the mumps virus.
Closterovirus, also known as beet yellows viral group, is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are 17 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem. This genus has a probably worldwide distribution and includes among other viral species the Beet yellows virus and Citrus tristeza virus, rather economically important plant diseases. At least some species require vectors such as aphids or mealybugs for their transmission from plant to plant.
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template.
Glycine receptor subunit alpha-1 is a protein that in humans is encoded by the GLRA1 gene.
Alloherpesviridae is a family of viruses in the order Herpesvirales. This family includes the species that infect fish and amphibians. Phylogenetic studies have confirmed the validity of this family and suggest that it may be divided into two clades: one consisting of viruses from cyprinid and anguillid hosts and the other of viruses from ictalurid, salmonid, acipenserid, and ranid hosts. There are currently 13 species in this family, divided among four genera. A disease associated with this family includes channel catfish disease.
Grapevine leafroll-associated virus (GLRaV) is a name for a group of viruses that infect grapevine.
Grapevine virus D (GVB) is a plant virus species in the genus Vitivirus, associated with rugose wood condition of grapevine.
Grapevine leafroll-associated virus 2 (GRLaV2) is a virus infecting grapevine in the genus Closterovirus. It is associated with rugose wood condition of grapevine.According to Bosciai, 1995, grapevine corky bark-associated virus (GCBaV) is a variant of GRLaV2.
Grapevine leafroll-associated virus 1 (GRLaV-1) is a virus infecting grapevine in the genus Ampelovirus.
Grapevine leafroll-associated virus 4 (GRLaV-4) is a virus infecting grapevine in the genus Ampelovirus.
Ampelovirus is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are 13 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem.
Velarivirus is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are eight species in this genus. Diseases associated with this genus include: GLRaV-7: symptomless in white-berried grapevine cultivar from Albania. However, it induces leafroll symptoms onto grafted cv. cabernet.
Positive-strand RNA 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. Positive-strand RNA viruses encode an RNA-dependent RNA polymerase (RdRp) which is used during replication of the genome to synthesize a negative-sense antigenome that is then used as a template to create a new positive-sense viral genome.
David Arthur John Tyrrell was a British virologist who was the director of the Common Cold Unit, which investigated viruses that caused common colds. He discovered the first human coronavirus in 1965. With June Almeida he made the first comparative study of human and chicken coronaviruses in 1967, and invented the name coronavirus in 1968.
Negative-strand RNA viruses are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid. They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the viral genome, RdRp synthesizes a positive-sense antigenome that it uses as a template to create genomic negative-sense RNA. Negative-strand RNA viruses also share a number of other characteristics: most contain a viral envelope that surrounds the capsid, which encases the viral genome, −ssRNA virus genomes are usually linear, and it is common for their genome to be segmented.
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.
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 replicate the genome. Viruses in this kingdom also share a number of characteristics involving evolution, including high rates of genetic mutations, recombinations, and reassortments.
