Birnaviridae

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Birnaviridae
ODR.Birna.Fig1.v1.c.png
Infectious bursal disease virus particle
Virus classification Red Pencil Icon.png
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: incertae sedis
Family:Birnaviridae

Birnaviridae is a family of double-stranded RNA viruses. [1] Salmonid fish, birds and insects serve as natural hosts. There are currently 11 species in this family, divided among seven genera. [2] Diseases associated with this family include infectious pancreatic necrosis in salmonid fish, which causes significant losses to the aquaculture industry, with chronic infection in adult salmonid fish and acute viral disease in young salmonid fish. [2] [3]

Contents

Structure

Viruses in family Birnaviridae are non-enveloped, with icosahedral single-shelled geometries, and T=13 symmetry. The diameter is around 70 nm. [2] [3]

Genome

Genome of infectious bursal disease virus of family Birnaviridae ODR.Birna.Fig3.v3 (1).png
Genome of infectious bursal disease virus of family Birnaviridae

The genome is composed of linear, bi-segmented, double-stranded RNA. It is around 5.9–6.9 kbp in length and codes for five to six proteins. Birnaviruses encode the following proteins:

RNA-directed RNA polymerase (VP1), which lacks the highly conserved Gly-Asp-Asp (GDD) sequence, a component of the proposed catalytic site of this enzyme family that exists in the conserved motif VI of the palm domain of other RNA-directed RNA polymerases. [4]

The large RNA segment, segment A, of birnaviruses codes for a polyprotein (N-VP2-VP4-VP3-C) [5] that is processed into the major structural proteins of the virion: VP2, VP3 (a minor structural component of the virus), and into the putative protease VP4. [5] VP4 protein is involved in generating VP2 and VP3. [5] recombinant VP3 is more immunogenic than recombinant VP2. [6]

Infectious pancreatic necrosis virus (IPNV), a birnavirus, is an important pathogen in fish farms. Analyses of viral proteins showed that VP2 is the major structural and immunogenic polypeptide of the virus. [7] [8] All neutralizing monoclonal antibodies are specific to VP2 and bind to continuous or discontinuous epitopes. The variable domain of VP2 and the 20 adjacent amino acids of the conserved C-terminal are probably the most important in inducing an immune response for the protection of animals. [7]

Non structural protein VP5 is found in RNA segment A.[ citation needed ] The function of this small viral protein is unknown. It is believed to be involved in influencing apoptosis, but studies are not completely concurring. The protein can not be found in the virion.[ citation needed ]

Viral Replication

Viral replication is cytoplasmic. Entry into the host cell is achieved by cell receptor endocytosis. Replication follows the double-stranded RNA virus replication model in the cytoplasm. Double-stranded RNA virus transcription is the method of transcription in cytoplasm. The virus is released by budding. Salmonid fish (Aquabirnavirus), young sexually immature chickens (Avibirnavirus), insects (Entomobirnavirus), and blotched snakehead fish (Blosnavirus) as the natural host. Transmission routes are contact. [2] [3]

Taxonomy

Phylogenetic tree of Birnaviridae ODR.Birna.Fig4.v7.png
Phylogenetic tree of Birnaviridae

The following genera are recognized:

Related Research Articles

<span class="mw-page-title-main">RNA virus</span> Subclass of viruses

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.

<span class="mw-page-title-main">Poliovirus</span> Enterovirus

A poliovirus, the causative agent of polio, is a serotype of the species Enterovirus C, in the family of Picornaviridae. There are three poliovirus serotypes: types 1, 2, and 3.

<i>Hepadnaviridae</i> Family of viruses

Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.

<span class="mw-page-title-main">Rubella virus</span> Species of virus

Rubella virus (RuV) is the pathogenic agent of the disease rubella, transmitted only between humans via the respiratory route, and is the main cause of congenital rubella syndrome when infection occurs during the first weeks of pregnancy.

<i>Nodaviridae</i> Family of viruses

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 the family, assigned to two genera.

<span class="mw-page-title-main">RNA-dependent RNA polymerase</span> Enzyme that synthesizes RNA from an RNA template

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.

Drosophila X virus (DXV) belongs to the Birnaviridae family of viruses. Birnaviridae currently consists of three genera. The first genus is Entomobirnavirus, which contains DXV. The next genus is Aquabirnavirus, containing infectious pancreatic necrosis virus (IPNV). The last genus is Avibirnavirus, which contains infectious bursal disease virus (IBDV). All of these genera contain homology in three specific areas of their transcripts. The homology comes from the amino and carboxyl regions of preVP2, a small 21-residue-long domain near the carboxyl terminal of VP3, and similar small ORFs sequences.

<i>Crinivirus</i> Genus of viruses

Crinivirus, formerly the lettuce infectious yellows virus group, is a genus of viruses, in the family Closteroviridae. They are linear, single-stranded positive sense RNA viruses. There are 14 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem.

Infectious hematopoietic necrosis virus (IHNV), is a negative-sense single-stranded, bullet-shaped RNA virus that is a member of the Rhabdoviridae family, and from the genus Novirhabdovirus. It causes the disease known as infectious hematopoietic necrosis in salmonid fish such as trout and salmon. The disease may be referred to by a number of other names such as Chinook salmon disease, Coleman disease, Columbia River sockeye disease, Cultus Lake virus disease, Oregon sockeye disease, Sacramento River Chinook disease and sockeye salmon viral disease. IHNV is commonly found in the Pacific Coast of Canada and the United States, and has also been found in Europe and Japan. The first reported epidemics of IHNV occurred in the United States at the Washington and the Oregon fish hatcheries during the 1950s. IHNV is transmitted following shedding of the virus in the feces, urine, sexual fluids, and external mucus and by direct contact or close contact with surrounding water. The virus gains entry into fish at the base of the fins.

<span class="mw-page-title-main">Double-stranded RNA viruses</span> Type of virus according to Baltimore classification

Double-stranded RNA viruses are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA polymerase (RdRp). The positive-strand RNA may be used as messenger RNA (mRNA) which can be translated into viral proteins by the host cell's ribosomes. The positive-strand RNA can also be replicated by the RdRp to create a new double-stranded viral genome.

<i>Picobirnavirus</i> Genus of viruses

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 might infect bacteria and possibly some other invertebrates. There are three species in this genus. Associated symptoms include gastroenteritis in animals and humans, though the disease association is unclear.

<i>Banna virus</i> Species of virus

Banna virus (BAV) is a virus belonging to Reoviridae, a family of segmented, non-enveloped, double-stranded RNA viruses. It is an arbovirus, being primarily transmitted to humans from the bite of infected mosquitoes of the genus Culex. Pigs and cattle have also been shown to become infected. The most common symptom of infection is fever, but in some cases encephalitis may occur. There is no specific treatment for infection, so treatment is aimed at alleviating the severity of symptoms until the immune system has cleared the infection.

Infectious pancreatic necrosis birnavirus Vp4 peptidase (EC 3.4.21.115, infectious pancreatic necrosis virus protease, IPNV Vp4 protease, IPNV Vp4 peptidase, NS protease, NS-associated protease, Vp4 protease) is an enzyme. This enzyme catalyses the following chemical reaction

Aquabirnavirus is a genus of viruses, in the family Birnaviridae. Salmonid fish serve as natural hosts. There are three species in this genus. A disease associated with this genus, Infectious pancreatic necrosis (IPN) in salmonid fish, causes significant losses to the aquaculture industry. Chronic infection in adults, and acute viral disease in young salmonid fish can occur.

<i>Avibirnavirus</i> Genus of viruses

Avibirnavirus is a genus of viruses in family Birnaviridae. There is a single species in this genus: Infectious bursal disease virus, which infects chickens and other fowl. It causes severe inflammation of the bursa of Fabricius, and causes considerable morbidity and mortality.

Blosnavirus is a genus of viruses, in the family Birnaviridae. Blotched snakehead fish serve as natural hosts. There are two species in this genus.

Entomobirnavirus is a genus of viruses in the family Birnaviridae. Its natural host is the fly Drosophila melanogaster. There are two species in this genus.

<span class="mw-page-title-main">Quadriviridae</span> Family of viruses

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 quadripartite genome of its members where in Latin quad means four. There is only one species in this family: Rosellinia necatrix quadrivirus 1.

Triatoma virus (TrV) is a virus belonging to the insect virus family Dicistroviridae. Within this family, there are currently 3 genera and 15 species of virus. Triatoma virus belongs to the genus Cripavirus. It is non-enveloped and its genetic material is positive-sense, single-stranded RNA. The natural hosts of triatoma virus are invertebrates. TrV is a known pathogen to Triatoma infestans, the major vector of Chagas disease in Argentina which makes triatoma virus a major candidate for biological vector control as opposed to chemical insecticides. Triatoma virus was first discovered in 1984 when a survey of pathogens of triatomes was conducted in the hopes of finding potential biological control methods for T. infestans.

<i>Astroviridae</i> Family of viruses

Astroviridae is a family of non-enveloped ssRNA viruses that cause infections in different animals. The family name is derived from the Greek word astron ("star") referring to the star-like appearance of spikes projecting from the surface of these small unenveloped viruses. Astroviruses were initially identified in humans but have since been isolated from other mammals and birds. This family of viruses consists of two genera, Avastrovirus (AAstV) and Mamastrovirus (MAstV). Astroviruses most frequently cause infection of the gastrointestinal tract but in some animals they may result in encephalitis, hepatitis (avian) and nephritis (avian).

References

  1. Delmas, B; Attoui, H; Ghosh, S; Malik, YS; Mundt, E; Vakharia, VN; Ictv Report, Consortium (January 2019). "ICTV virus taxonomy profile: Birnaviridae". The Journal of General Virology. 100 (1): 5–6. doi: 10.1099/jgv.0.001185 . PMID   30484762.
  2. 1 2 3 4 "Birnaviridae—Birnaviridae—dsRNA Viruses". International Committee on Taxonomy of Viruses (ICTV). Retrieved 16 October 2019.[ dead link ]
  3. 1 2 3 "Viral Zone". ExPASy. Retrieved 12 June 2015.
  4. Shwed PS, Dobos P, Cameron LA, Vakharia VN, Duncan R (May 2002). "Birnavirus VP1 proteins form a distinct subgroup of RNA-dependent RNA polymerases lacking a GDD motif". Virology. 296 (2): 241–250. doi: 10.1006/viro.2001.1334 . PMID   12069523.
  5. 1 2 3 Jagadish MN, Staton VJ, Hudson PJ, Azad AA (March 1988). "Birnavirus precursor polyprotein is processed in Escherichia coli by its own virus-encoded polypeptide". J. Virol. 62 (3): 1084–7. doi:10.1128/JVI.62.3.1084-1087.1988. PMC   253673 . PMID   2828658.
  6. Moon CH, Do JW, Cha SJ, Bang JD, Park MA, Yoo DJ, Lee JM, Kim HG, Chung DK, Park JW (October 2004). "Comparison of the immunogenicity of recombinant VP2 and VP3 of infectious pancreatic necrosis virus and marine birnavirus". Arch. Virol. 149 (10): 2059–68. doi:10.1007/s00705-004-0339-2. PMID   15669113. S2CID   22958612.
  7. 1 2 Heppell J, Tarrab E, Lecomte J, Berthiaume L, Arella M (December 1995). "Strain variability and localization of important epitopes on the major structural protein (VP2) of infectious pancreatic necrosis virus". Virology. 214 (1): 40–9. doi: 10.1006/viro.1995.9956 . PMID   8525637.
  8. Nobiron I, Galloux M, Henry C, Torhy C, Boudinot P, Lejal N, Da Costa B, Delmas B (February 2008). "Genome and polypeptides characterization of Tellina virus 1 reveals a fifth genetic cluster in the Birnaviridae family". Virology. 371 (2): 350–61. doi: 10.1016/j.virol.2007.09.022 . PMID   17976679.