Citizendia
Your Ad Here

Poxviruses
Virus classification
Group: Group I (dsDNA)
Family: Poxviridae
Genera

Subfamily Chordopoxvirinae
   Orthopoxvirus
   Parapoxvirus
   Avipoxvirus
   Capripoxvirus
   Leporipoxvirus
   Suipoxvirus
   Molluscipoxvirus
   Yatapoxvirus
Subfamily Entomopoxvirinae
   Entomopoxvirus A
   Entomopoxvirus B
   Entomopoxvirus C

Poxviruses (members of the family Poxviridae) are viruses that can, as a family, infect both vertebrate and invertebrate animals. Virus classification involves naming and placing Viruses into a taxonomic system A DNA virus is a Virus that has DNA as its Genetic material and replicates using a DNA-dependent DNA polymerase. Orthopoxvirus is a Genus of poxviruses that includes many Species isolated from Mammals such as Buffalopox virus Parapoxviruses belong to the Poxviridae family Like all members of that family they are oval relatively large double-stranded DNA viruses Avipoxvirus is a member of the Poxviridae family The Poxviridae family is the family of viruses which cause the victim organism to have poxes as a symptom A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes An invertebrate is an Animal lacking a Vertebral column. The group includes 98% of all animal Species — all animals except those in the Chordate

The only poxvirus not in genus Orthopoxvirus known to specifically infect humans is the molluscum contagiosum virus (MCV). Molluscum contagiosum ( MC) is a viral infection of the Skin or occasionally of the Mucous membranes. [1]

Contents

Structure

Poxviridae viral particles (virions) are generally enveloped (external enveloped virion- EEV), though the intracellular mature virion (IMV) form of the virus, which contains different envelope, is also infectious. A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable 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. The virion size is around 200 nm in diameter and 300 nm in length and carries its genome in a single, linear, double-stranded segment of DNA. A nanometre ( American spelling: nanometer, symbol nm) ( Greek: νάνος nanos dwarf; μετρώ metrό count) is a A nanometre ( American spelling: nanometer, symbol nm) ( Greek: νάνος nanos dwarf; μετρώ metrό count) is a In classical genetics the genome of a Diploid Organism including Eukarya refers to a full set of chromosomes or genes in a Gamete, thereby [2] By comparison, Rhinovirus is 1/10th as large as a typical Poxviridae virion. Rhinovirus (from the Greek rhin - which means "nose" is a genus of the Picornaviridae family of Viruses Rhinoviruses [3]

Replication

Replication of the poxvirus involves several stages. The first thing the virus does is to bind to a receptor on the host cell surface; the receptors for the poxvirus are currently unknown. A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable After binding to the receptor, the virus enters the cell where it uncoats. Uncoating of the virus is a two step process. Firstly the outer membrane is removed as the particle enters the cell; secondly the virus particle (without the outer membrane) is uncoated further to release the core into the cytoplasm. The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. The pox viral genes are expressed in two phases. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance The early genes are expressed first. These genes encode the non-structural protein, including proteins necessary for replication of the viral genome, and are expressed before the genome is replicated. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In classical genetics the genome of a Diploid Organism including Eukarya refers to a full set of chromosomes or genes in a Gamete, thereby The late genes are expressed after the genome has been replicated and encode the structural proteins to make the virus particle. The assembly of the virus particle occurs in the cytoskeleton of the cell and is a complex process that is poorly understood but is currently being researched. cytoskeleton (also CSK is a cellular " Scaffolding " or " Skeleton " contained within the Cytoplasm. Considering the fact that this virus is large and complex, replication is relatively quick taking only 12 hours approximately. The replication of this virus is unusual for a virus with double stranded DNA genome because it encodes its own machinery for genome replication and therefore the replication occurs in the cytoplasm. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Most viruses with a double stranded DNA genome replicate in the nucleus and use the host cells genome replication machinery. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed

Taxonomy

The name of the family, Poxviridae, is a legacy of the original grouping of viruses associated with diseases that produced poxs in the skin. Modern viral classification is based on the shape and molecular features of viruses, and the smallpox virus remains as the most notable member of the family. Smallpox is an Infectious disease unique to humans caused by either of two virus variants named Variola major and Variola minor.

The following genera are currently included here:

Examples

Vaccinia virus

Main article: Vaccinia virus

The prototype of poxvirus family is vaccinia virus, which has been used as a successful vaccine to eradicate smallpox virus. Orthopoxvirus is a Genus of poxviruses that includes many Species isolated from Mammals such as Buffalopox virus Vaccinia virus ( VACV or VV) is a large complex enveloped Virus belonging to the Poxvirus family Cowpox is a Disease of the skin that is caused by a Virus known as the Cowpox virus. Vaccinia virus ( VACV or VV) is a large complex enveloped Virus belonging to the Poxvirus family Smallpox is an Infectious disease unique to humans caused by either of two virus variants named Variola major and Variola minor. Parapoxviruses belong to the Poxviridae family Like all members of that family they are oval relatively large double-stranded DNA viruses Orf is an exanthemous Disease caused by a Parapox virus and occurring primarily in Sheep and Goats It is also known as contagious Avipoxvirus is a member of the Poxviridae family The Poxviridae family is the family of viruses which cause the victim organism to have poxes as a symptom Fowlpox is a worldwide disease of Poultry caused by Viruses of the family Poxviridae and the genus Avipoxvirus. Sheeppox and goatpox are diseases caused by separate Viruses of the genus Capripoxvirus (Sheeppox virus Goatpox virus and Lumpyskin disease The Myxoma virus causes Myxomatosis in rabbits and was used as a pest control in Australia. Swinepox is a worldwide disease of Pigs caused by a Virus of the family Poxviridae and the genus Suipoxvirus. Molluscum contagiosum ( MC) is a viral infection of the Skin or occasionally of the Mucous membranes. Vaccinia virus ( VACV or VV) is a large complex enveloped Virus belonging to the Poxvirus family Vaccinia virus ( VACV or VV) is a large complex enveloped Virus belonging to the Poxvirus family Vaccinia virus is also used as an effective tool for foreign protein expression to elicite strong host immune response. Vaccinia virus enters cells mainly by cell fusion, although currently the receptor is not known. Virus contains three classes of genes, early, intermediate and late, that are transcribed by viral RNA polymerase and associated transcription factors. Vaccinia virus replicates its genome in cytoplasm of the infected cells and after late gene expression virion morphogenesis produces IMV that contains envelope, although the origin of the envelope membrane is still unknown. IMV is transported to Golgi to be wrapped additional two membrane to become intracellular enveloped virus (IEV). IEV transports along microtubules to reach cell periphery and fuse with plasma membrane to become cell-associated enveloped virus (CEV) that triggers actin tails on cell surfaces or is releared as EEV.

History

Viruses, especially smallpox have been known about for centuries. One of the earliest documented evidence is of the Egyptian pharaoh Ramses V who is known to have died from smallpox nearly 2000 years BC. Smallpox was thought to have been transferred to Europe around the early 700s and then to the Americas in the early 1500s. It is widely accepted that the main defeat of the Aztecs was due to a smallpox epidemic and within two years over 3. 2 million Aztecs died. This death toll can be attributed to the American population's complete lack of sensitization to the virus as children. A century after Edward Jenner showed that the less potent cow pox could be used to effectively vaccinate against the more deadly smallpox, a worldwide effort to vaccinate everyone against smallpox began with the ultimate goal to rid the world of the plague-like epidemic. The World Health Organization (WHO) declared the virus officially eradicated in 1977, with samples retained at laboratories within the two then global superpowers, the United States and the Soviet Union. Post September 11 2001 the American and UK governments have had increased concern over the use of smallpox, or a small pox like disease, in bio-terrorism.

See also

Viruses templates

References

  1. ^ "Pathogenic Molluscum Contagiosum Virus Sequenced" (August 1996). Antiviral Agents Bulletin: 196-7. Biotechnology Information Institute.  
  2. ^ International Committee on Taxonomy of Viruses (2004-06-15). "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Events 763 BC - Assyrians record a Solar eclipse that will be used to fix the Chronology of Mesopotamian history ICTVdb Descriptions: 58. Poxviridae. Retrieved on 2005-02-26. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 747 BC - Epoch (origin of Ptolemy 's Nabonassar Era 364 - Valentinian I is proclaimed
  3. ^ How Big is a ... ? at Cells Alive!. Retrieved 2005-02-26.

External links

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic