Navigation Links
Retrovirus


Alpharetrovirus
Betaretrovirus
Gammaretrovirus
Deltaretrovirus
Epsilonretrovirus
Lentivirus
Spumavirus A retrovirus is a virus which has a genome consisting of two identical plus sense RNA molecules. It relies on reverse transcriptase to perform a kind of reverse transcription of its genome from RNA into DNA for insertion by integrase into the host's genome. The virus itself is just a storage form for its nucleic acid genome; the reverse transcription takes place in the host's cytosol. The retroviral DNA, when integrated into the host's genome, is termed a provirus.

While transcription was classically thought to only occur from DNA to RNA, reverse transcriptase transcribes RNA into DNA. The term "retro" in retrovirus refers to this reversal of the Central dogma of molecular biology. Reverse transcriptase activity outside of retroviruses has been found in almost all eukaryotes, enabling the generation and insertion of new copies of retrotransposons into the host genome.

Because reverse transcription is missing the usual "proofreading" of DNA transcription, this kind of virus mutates very often. This enables the virus to grow resistant to antiviral pharmaceuticals quickly, and is one of the main reasons why an effective vaccine for HIV has not been developed yet.

Among others, retrovirus genomes commonly contain three genes, that encode proteins that can be found back in the mature virus:

Four identified human retroviruses (HTLV 1&2, HIV 1&2) attack CD4 cells. Another feature common to all retroviruses is a lipid coating surrounding their capsid. It is essential for their propagation. This explains why retroviruses can be made inactive by just washing hands.

Studies of retroviruses led to the first demonstrated synthesis of DNA from RNA templates, a fundamental mode for transferring genetic material that occurs in both eukaryotes and prokaryotes. Certain groups speculate that the processes followed by retroviruses (that is, RNA>DNA>RNA>Protein) may be the key to the evolution of DNA; thus, that in the "primordial soup", retroviruses evolved to create DNA from the RNA templates, and it was subsequently adopted by cellular organisms due to the increased chemical stability of DNA.

The following genera are included here:

  • Genus Alpharetrovirus ; type species: Avian leucosis virus
  • Genus Betaretrovirus ; type species: Mouse mammary tumour virus
  • Genus Gammaretrovirus ; type species: Murine leukeamia virus ; others include Feline leukemia virus
  • Genus Deltaretrovirus ; type species: Bovine leukaemia virus ; others include Human T-lymphotropic virus
  • Genus Epsilonretrovirus ; type species: Walleye dermal sarcoma virus
  • Genus Lentivirus ; type species: Human immunodeficiency virus 1; others include Simian, Feline immunodeficiency viruses
  • Genus Spumavirus ; type species: Chimpanzee foamy virus

These were previously divided into three subfamilies (Oncovirinae, Lentivirinae, and Spumavirinae), but with our current knowledge of retroviruses, this is no longer appropriate.


See also

External links


'"/>


(Date:11/21/2014)... Wash. , Nov. 20, 2014 C-Labs ... for the Internet of Things (IoT), today announced the ... of chief operating officer. Previously a strategic advisor to ... finance, and operations. Mr. Traynor is based out of ... . He reports to Chris Muench , Chief ...
(Date:11/18/2014)...   News Highlights: ... The Partners Data Lake, an agile data and ... will allow researcher and clinicians to explore and ... lives of patients , The Partners Data ... the Partners system, breaking down physical barriers for ...
(Date:11/15/2014)... YORK , Nov. 13, 2014  While we may ... technology Doctor McCoy used in "Star Trek" to gain instant ... tools designed to work with smartphones and tablets for monitoring ... of the healthcare world. This may seem a tad Orwellian ... ready to adopt some of these technological opportunities into their ...
Breaking Biology News(10 mins):C-Labs Names Former Microsoft and Bsquare Executive as Chief Operating Officer 2Partners HealthCare and EMC Unite to Solve Health Care's Toughest Challenges Using Big Data 2Partners HealthCare and EMC Unite to Solve Health Care's Toughest Challenges Using Big Data 3Partners HealthCare and EMC Unite to Solve Health Care's Toughest Challenges Using Big Data 4Partners HealthCare and EMC Unite to Solve Health Care's Toughest Challenges Using Big Data 5Americans May Be Ready for a Brave New World of Healthcare 2Americans May Be Ready for a Brave New World of Healthcare 3Americans May Be Ready for a Brave New World of Healthcare 4
... Registration is now open for Disease Models & ... Mechanisms. This one-day Symposium will ... and disease processes at the cellular and whole-organism ... be used to address this issue. It is ...
... flower, created by the union of two foreign plant species, ... Genetic changes in this attractive yellow-flowered hybrid have allowed it to ... new species that has originated in the wild in the last ... to have originated in this way, yet only a handful of ...
... A San Francisco State University biologist has released the ... bee populations and has found low numbers of bees in ... habitat loss is one of the primary reasons for sharp ... Now the researcher plans to add to her data ...
Cached Biology News:Rare glimpse into the origin of species 2SF State researcher releases first results from nationwide bee count 2SF State researcher releases first results from nationwide bee count 3
Other biology definitionOther Tags