Chordopoxvirinae

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Chordopoxvirinae
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Varidnaviria
Kingdom: Bamfordvirae
Phylum: Nucleocytoviricota
Class: Pokkesviricetes
Order: Chitovirales
Family: Poxviridae
Subfamily:Chordopoxvirinae
Genera

See text

Chordopoxvirinae is a subfamily of viruses in the family Poxviridae . Vertebrates and arthropods serve as natural hosts. Currently, 52 species are placed in this subfamily, divided among 18 genera. Diseases associated with this subfamily include smallpox. [1] [2]

Contents

Four genera in this subfamily contain species that infect humans: Molluscipoxvirus, Orthopoxvirus, Parapoxvirus , and Yatapoxvirus .

Virology

The virions are generally enveloped though the intracellular mature virion form of the virus, which contains a different envelope and is also infectious. They vary in their shape depending upon the species but are generally shaped like a brick or as an oval form similar to a rounded brick because they are wrapped by the endoplasmic reticulum. The virion is exceptionally large, around 200  nm in diameter and 300 nm in length, and carries its genome in a single, double-stranded segment of DNA. [3] Genomes are linear, around 130–375 kb in length. [1]

GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
YatapoxvirusBrick-shapedEnvelopedLinearMonopartite
CervidpoxvirusBrick-shapedEnvelopedLinearMonopartite
LeporipoxvirusBrick-shapedEnvelopedLinearMonopartite
SuipoxvirusBrick-shapedEnvelopedLinearMonopartite
MolluscipoxvirusBrick-shapedEnvelopedLinearMonopartite
CrocodylidpoxvirusOvoidEnvelopedLinearMonopartite
CapripoxvirusBrick-shapedEnvelopedLinearMonopartite
OrthopoxvirusBrick-shapedEnvelopedLinearMonopartite
AvipoxvirusBrick-shapedEnvelopedLinearMonopartite
ParapoxvirusOvoidEnvelopedLinearMonopartite

Lifecycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host glycosaminoglycans (GAGs), which mediate endocytosis of the virus into the host cell. Fusion with the plasma membrane releases the core into the host cytoplasm. In the early phase, early genes are transcribed in the cytoplasm by viral RNA polymerase. Early expression begins at 30 minutes postinfection. The core is completely uncoated as early expression ends, the viral genome is then free in the cytoplasm. In the intermediate phase, intermediate genes are expressed, triggering genomic DNA replication about 100 minutes after infection. In the late phase, late genes are expressed from 140 min to 48 hours postinfection, producing all structural proteins. Assembly of progeny virions starts in cytoplasmic viral factories, producing a spherical, immature particle. This virus particle matures into brick-shaped intracellular mature virion, which can be released upon cell lysis, or can acquire a second double membrane from trans-Golgi and bud as external enveloped virion host receptors, which mediates endocytosis. Replication follows the DNA strand displacement model. DNA-templated transcription is the method of transcription. The virus exits the host cell by microtubular outwards viral transport, and exists in occlusion bodies after cell death and remains infectious until finding another host. Humans, vertebrates, and arthropods serve as the natural host. Transmission routes are fomite, contact, and airborne particles. [1]

GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
YatapoxvirusMonkeys; baboonsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmContact; insects
CervidpoxvirusDeerNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmUnknown
LeporipoxvirusLagomorph; squirrelsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmArthropods; contact
SuipoxvirusSwineNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmUnknown
MolluscipoxvirusHumansNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmSex; contact
CrocodylidpoxvirusCrocodilesNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmUnknown
CapripoxvirusSheep; goat; cattleNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmArthropods; contact
OrthopoxvirusHumans; mammalsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmVariola virus; Respiratory; contact; zoonosis
AvipoxvirusBirdsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmArthropods; aerosol
ParapoxvirusHumans; mammalsNoneGlycosaminoglycansLysis; buddingCytoplasmCytoplasmZoonosis; contact

Taxonomy

The classification in this subfamily is based on the morphology, nucleic acid type, mode of replication, host organisms, and type of disease caused.

Nine genera in this subfamily are recognized; also, a number of species have not yet been assigned to a genus.

The species in the genus Avipoxvirus infect birds; those in the genera Caiman poxvirus and Crocodylipoxvirus both infect crocodilians.

The other genera in this subfamily infect mammals.

The following genera are recognized: [2]

Evolution

The last common ancestor of the extant poxviruses that infect vertebrates existed 0.5  million years ago. The genus Avipoxvirus diverged from the ancestor 249 ± 69 thousand years ago. The ancestor of the genus Orthopoxvirus was next to diverge from the other clades at 0.3  million years ago. A second estimate of this divergence time places this event at 166 ± 43,000 years ago. [4] The division of the Orthopox into the extant species occurred about 14,000 years ago. The genus Leporipoxvirus diverged around 137 ± 35,000 years ago. This was followed by the ancestor of the genus Yatapoxvirus. The last common ancestor of the Capripoxvirus and Suipoxvirus diverged 111 ± 29,000 years ago.[ citation needed ]

A Bayesian study of orthopox genomes suggests that the unclassified Yoka poxvirus diverged from the lineage that gave rise to the orthopoxviruses roughly 90,000 years ago. [5] The orthopox viruses diverged from the other pox viruses about 10,000 years ago. Camelpox, taterapox, and variola viruses arose 3,500 years ago and horsepox virus 3,000 years ago. These viruses may have arisen in the Horn of Africa.[ citation needed ]

Another Bayesian study suggests that variola arose about 3500 years ago. [6]

Related Research Articles

<i>Poxviridae</i> Family of viruses

Poxviridae is a family of double-stranded DNA viruses. Vertebrates and arthropods serve as natural hosts. There are currently 83 species in this family, divided among 22 genera, which are divided into two subfamilies. Diseases associated with this family include smallpox.

<i>Parapoxvirus</i> Genus of viruses

Parapoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Chordopoxvirinae. Like all members of the family Poxviridae, they are oval, relatively large, double-stranded DNA viruses. Parapoxviruses have a unique spiral coat that distinguishes them from other poxviruses. Parapoxviruses infect vertebrates, including a wide selection of mammals, and humans.

Orthopoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. Vertebrates, including mammals and humans, and arthropods serve as natural hosts. There are 12 species in this genus. Diseases associated with this genus include smallpox, cowpox, horsepox, camelpox, and monkeypox. The most widely known member of the genus is Variola virus, which causes smallpox. It was eradicated globally by 1977, through the use of Vaccinia virus as a vaccine. The most recently described species is the Alaskapox virus, first isolated in 2015.

<span class="mw-page-title-main">Camelpox</span> Disease of camels caused by the Camelpox virus

Camelpox is a disease of camels caused by the camelpox virus (CMPV) of the family Poxviridae, subfamily Chordopoxvirinae, and the genus Orthopoxvirus. It causes skin lesions and a generalized infection. Approximately 25% of young camels that become infected will die from the disease, while infection in older camels is generally more mild. Although rare, the infection may spread to the hands of those that work closely with camels.

<i>Molluscum contagiosum virus</i> Species of virus

Molluscum contagiosum virus (MCV) is a species of DNA poxvirus that causes the human skin infection molluscum contagiosum. Molluscum contagiosum affects about 200,000 people a year, about 1% of all diagnosed skin diseases. Diagnosis is based on the size and shape of the skin lesions and can be confirmed with a biopsy, as the virus cannot be routinely cultured. Molluscum contagiosum virus is the only species in the genus Molluscipoxvirus. MCV is a member of the subfamily Chordopoxvirinae of family Poxviridae. Other commonly known viruses that reside in the subfamily Chordopoxvirinae are variola virus and monkeypox virus.

<span class="mw-page-title-main">Canarypox</span> Viral disease of birds

Canarypox virus (CNPV) is an Avipoxvirus and etiologic agent of canarypox, a disease of wild and captive birds that can cause significant losses. Canarypox can enter human cells, but it cannot survive and multiply in human cells. There is a live viral vaccine available which may have beneficial properties against human cancer when used as a mammalian expression vector.. Furthermore, the Poximune C vaccine does offer direct protection against CNPV in susceptible birds.

Avipoxvirus is a genus of viruses within the family Poxviridae. Poxviridae is the family of viruses which cause the afflicted organism to have poxes as a symptom. Poxviruses have generally large genomes, and other such examples include smallpox and monkeypox. Members of the genus Avipoxvirus infect specifically birds. Avipoxviruses are unable to complete their replication cycle in non-avian species. Although it is comparably slow-spreading, Avipoxvirus is known to cause symptoms like pustules full of pus lining the skin and diphtheria-like symptoms. These diphtheria-like symptoms might include diphtheric necrotic membranes lining the mouth and the upper respiratory tract. Like other avian viruses, it can be transmitted through vectors mechanically such as through mosquitoes. There is no evidence that this virus can infect humans.

<i>Iridoviridae</i> Family of viruses

Iridoviridae is a family of viruses with double-stranded DNA genomes. Amphibians, fish, and invertebrates such as arthropods serve as natural hosts. There are currently 22 species in this family, divided among two subfamilies and seven genera.

Turkeypox virus is a virus of the family Poxviridae and the genus Avipoxvirus that causes turkeypox. It is one of the most common diseases in the wild turkey population. Turkeypox, like all avipoxviruses, is transmitted either through skin contact or by arthropods acting as mechanical vectors.

Yatapoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Chordopoxvirinae. Monkeys and baboons serve as natural hosts. There are two species in this genus. Diseases associated with this genus include: histiocytomas, tumor-like mass of mononuclear cells.

Entomopoxvirinae is a subfamily of viruses, in the family Poxviridae. Insects, human, vertebrates, and arthropods serve as natural hosts. There are currently 31 species in this subfamily, divided among 4 genera with one species unassigned to a genus. Diseases associated with this subfamily include: impairment of motility and development.

Capripoxvirus is a genus of viruses in the subfamily Chordopoxvirinae and the family Poxviridae. Capripoxviruses are among the most serious of all animal poxviruses. All CaPV are notifiable diseases to the OIE. Sheep, goat, and cattle serve as natural hosts. These viruses cause negative economic consequences by damaging hides and wool and forcing the establishment of trade restrictions in response to an outbreak. The genus consists of three species: sheeppox virus (SPPV), goatpox virus (GTPV), and lumpy skin disease virus (LSDV). They share no serological relationship with camel pox, horse pox, or avian poxes. Capripoxviruses for sheeppox and goatpox infect only sheep and goat respectively. However, it is probable that North American relatives, the mountain goat and mountain sheep, may be susceptible to the strains but has not been experimentally proven. Lumpy skin disease virus affects primarily cattle, but studies have been shown that giraffes and impala are also susceptible to LSDV. Humans cannot be infected by Capripoxviruses.

<i>Monkeypox virus</i> Species of double-stranded DNA virus

The monkeypox virus, is a species of double-stranded DNA virus that causes mpox disease in humans and other mammals. The monkeypox virus is a zoonotic virus belonging to the orthopoxvirus genus, making it closely related to the variola, cowpox, and vaccinia viruses. MPV is oval-shaped with a lipoprotein outer membrane. The genome is approximately 190 kb.

Alphaentomopoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Entomopoxvirinae. Coleoptera insects serve as natural hosts. There are seven species in this genus.

Cervidpoxvirus is a genus of viruses in the family Poxviridae in the subfamily Chordopoxvirinae. Deer serve as natural hosts. Only one species is in this genus: Mule deerpox virus.

Leporipoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Chordopoxvirinae. Lagomorphs and squirrels serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: myxomatosis.

Suipoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. Swine serve as natural hosts. There is only one species in this genus: Swinepox virus. Diseases associated with this genus include asymptomatic skin disease.

Crocodylidpoxvirus is a genus of viruses, in the family Poxviridae, in the subfamily Chordopoxvirinae. Crocodiles serve as natural hosts. There is only one species in this genus: Nile crocodilepox virus. Diseases associated with this genus include: nodular skin lesions in young animals. Symptoms vary from a nonfatal dermatitis to more severe disease characterized by ophthalmia, rhinitis resulting in asphyxia, and debilitating illness with stunting and high mortality.

Raccoonpox virus (RCN) is a double-stranded DNA virus and a member of the orthopoxviruses in the family Poxviridae and subfamily Chordopoxvirinae which consists of eight genera: Avipoxvirus, Capripoxvirus, Leporipoxvirus, Molluscipoxvirus, Orthopoxvirus, Parapoxvirus, Suipoxvirus and Yatapoxvirus Vertebrates are the natural host of Chordopoxvirinae subfamily viruses. More specifically, raccoons are the natural hosts of RCN. RCN was isolated in 1961 from the upper respiratory tissues of 2 raccoons in a group of 92 observably healthy raccoons trapped close to Aberdeen, Maryland.

<i>Red deerpox virus</i> Species of virus

Red deerpox virus (RDPV) is a species of virus in the genus Parapoxvirus. It has been reported in deer in New Zealand, and in wild ruminants in Italy.

References

  1. 1 2 3 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. 1 2 "Virus Taxonomy: 2019 Release". talk.ictvonline.org. International Committee on Taxonomy of Viruses. Retrieved 9 May 2020.
  3. International Committee on Taxonomy of Viruses (15 June 2004). "ICTVdb Descriptions: 58. Poxviridae". Archived from the original on 3 July 2007. Retrieved 26 February 2005.
  4. Babkin IV, Babkina IN (2011) Molecular dating in the evolution of vertebrate poxviruses. Intervirology 54(5):253-260. doi : 10.1159/000320964.
  5. Babkin IV, Babkina IN (2012) A retrospective study of the orthopoxvirus molecular evolution. Infect Genet Evol
  6. Babkin IV, Shelkunov SN (2008) Molecular evolution of poxviruses. Genetika 44(8):1029-1044