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Orthoretrovirinae
''Orthoretrovirinae'' is a subfamily of viruses belonging to ''Retroviridae'', a family of enveloped viruses that replicate in a host cell through the process of reverse transcription. The subfamily currently includes six genera, of which ''Lentivirus'' contains the human immunodeficiency virus (HIV). These viruses cause a variety of tumors, malignancies and immune deficiency disease in humans, other mammals and birds. A few, like Simian immunodeficiency virus Simian immunodeficiency virus (SIV) is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isolated fr ... (SIV), apparently cause no disease in their natural hosts. References Retroviridae Virus subfamilies {{virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retroviridae
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus ''retro'' (backward). The new DNA is then incorporated into the host cell genome by an integrase enzyme, at which point the retroviral DNA is referred to as a provirus. The host cell then treats the viral DNA as part of its own genome, transcribing and translating the viral genes along with the cell's own genes, producing the proteins required to assemble new copies of the virus. Many retroviruses cause serious diseases in humans, other mammals, and birds. Retroviruses have many subfamilies in three basic groups. * Oncoretroviruses (cancer-causing retroviruses) include human T-lymphotropic virus (HTLV) causing a type of leukemia in humans, and murine le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammaretrovirus
''Gammaretrovirus'' is a genus in the ''Retroviridae'' family. Example species are the murine leukemia virus and the feline leukemia virus. They cause various sarcomas, leukemias and immune deficiencies in mammals, reptiles and birds. Introduction Many endogenous retroviruses, closely related to exogenous gammaretroviruses, are present in the DNA of mammals (including humans), birds, reptiles and amphibians. Many also share a conserved RNA structural element called a core encapsidation signal. The avian reticuloendotheliosis viruses are not strictly avian viruses—it appears that reticuloendotheliosis viruses are mammalian viruses that were accidentally introduced into birds in the 1930s during research on malaria. As a potential vector for gene therapy, gammaretroviruses have some advantages over HIV as a lentiviral vector. Specifically, the gammaretroviral packaging system does not require the incorporation of any sequences overlapping with coding sequences of gag, pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simian Immunodeficiency Virus
Simian immunodeficiency virus (SIV) is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isolated from the mainland by rising sea levels about 11,000 years ago, it has been concluded that SIV has been present in monkeys and apes for at least 32,000 years, and probably much longer. Virus strains from three of these primate species, SIVsmm in sooty mangabeys, SIVgor in gorillas and SIVcpz in chimpanzees, are believed to have crossed the species barrier into humans, resulting in HIV-2 and HIV-1 respectively, the two HIV viruses. The most likely route of transmission of HIV-1 to humans involves contact with the blood of chimps and gorillas that are often hunted for bushmeat in Africa. Four subtypes of HIV-1 (M, N, O, and P) likely arose through four separate transmissions of SIV to humans, and the resulting HIV-1 group M strain most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpharetrovirus
''Alpharetrovirus'' is a genus of viruses in the family ''Retroviridae A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase ...''. The genus contains nine species. Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Alpharetrovirus avicarmilhil2'', Avian carcinoma Mill Hill virus 2 * ''Alpharetrovirus avifujsar'', Fujinami sarcoma virus * ''Alpharetrovirus avileu'', Avian leukosis virus * ''Alpharetrovirus avimyebla'', Avian myeloblastosis virus * ''Alpharetrovirus avimyecyt29'', Avian myelocytomatosis virus 29 * ''Alpharetrovirus avirousar'', Rous sarcoma virus * ''Alpharetrovirus avisar10'', Avian sarcoma virus CT10 * ''Alpharetrovirus aviUR2sar'', UR2 sarcoma virus * ''Alpharetrovirus aviY73sar'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaretrovirus
''Betaretrovirus'' is a genus of viruses in the Family (biology), family ''Retroviridae''. Example of viruses in the genus include: Mouse mammary tumor virus, enzootic nasal tumor virus (ENTV-1, ENTV-2), and simian retrovirus types 1, 2 and 3 (SRV-1, SRV-2, SRV-3). Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Betaretrovirus lan'', Langur virus * ''Betaretrovirus maspfimon'', Mason-Pfizer monkey virus * ''Betaretrovirus murmamtum'', Mouse mammary tumor virus * ''Betaretrovirus ovijaa'', Jaagsiekte sheep retrovirus * ''Betaretrovirus squmon'', Squirrel monkey retrovirus References External links Viralzone: Betaretrovirus Betaretroviruses Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltaretrovirus
''Deltaretrovirus'' is a genus of the ''Retroviridae'' family. It consists of exogenous horizontally transmitted viruses found in several groups of mammals. The genus contains Bovine leukemia virus and three species of primate T-lymphotropic virus. The genus of viruses is known for its propensity to target immune cells and oncogenicity, evident in the names of the four named species. Infection is usually asymptomatic, but inflammation and cancer can develop over time. Classification The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Deltaretrovirus bovleu'', Bovine leukemia virus * ''Deltaretrovirus priTlym1'', Primate T-lymphotropic virus 1 * ''Deltaretrovirus priTlym2'', Primate T-lymphotropic virus 2 * ''Deltaretrovirus priTlym3'', Primate T-lymphotropic virus 3 Two additional PTLVs are known but not recognized: HTLV-4 ( South Cameroon, 2005) and STLV-5 (Mac B43 strain, highly divergent PTLV-1). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilonretrovirus
''Epsilonretrovirus'' is a genus of viruses in the family ''Retroviridae A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase ...''. Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Epsilonretrovirus waldersar'', Walleye dermal sarcoma virus * ''Epsilonretrovirus walepihyp1'', Walleye epidermal hyperplasia virus 1 * ''Epsilonretrovirus walepihyp2'', Walleye epidermal hyperplasia virus 2 References External links * Epsilonretroviruses Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lentivirus
''Lentivirus'' is a genus of retroviruses that cause chronic and deadly diseases characterized by long incubation periods, in humans and other mammalian species. The genus includes the human immunodeficiency virus (HIV), which causes AIDS. Lentiviruses are distributed worldwide, and are known to be hosted in apes, cows, goats, horses, cats, and sheep as well as several other mammals. Lentiviruses can integrate a significant amount of viral complementary DNA into the DNA of the host cell and can efficiently infect nondividing cells, so they are one of the most efficient methods of gene delivery. They can become endogenous, integrating their genome into the host germline genome, so that the virus is henceforth inherited by the host's descendants. Classification Five serogroups of lentiviruses are recognized, reflecting the vertebrate hosts with which they are associated (primates, sheep and goats, horses, domestic cats, and cattle). The primate lentiviruses are distinguished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enveloped Virus
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. A viral envelope protein or E protein is a protein in the envelope, which may be acquired by the capsid from an infected host cell. Host cell infection process Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral membrane fusion protein. Many enveloped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Transcription
A reverse transcriptase (RT) is an enzyme used to convert RNA genome to DNA, a process termed reverse transcription. Reverse transcriptases are used by viruses such as HIV and hepatitis B virus, hepatitis B to replicate their genomes, by retrotransposon mobile genetic elements to proliferate within the host genome, and by eukaryote, eukaryotic cells to extend the telomeres at the ends of their Chromosome#Eukaryotes, linear chromosomes. The process does not violate the flows of genetic information as described by the classical central dogma of molecular biology, central dogma, but rather expands it to include transfers of information from RNA to DNA. Retroviral RT has three sequential biochemical activities: RNA-dependent DNA polymerase activity, ribonuclease H (RNase H), and DNA-dependent DNA polymerase activity. Collectively, these activities enable the enzyme to convert single-stranded RNA into double-stranded cDNA. In retroviruses and retrotransposons, this cDNA can then inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Immunodeficiency Virus
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, the average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the Subtypes of HIV, HIV subtype. In most cases, HIV is a sexually transmitted infection and HIV/AIDS#Transmission, occurs by contact with or transfer of blood, pre-ejaculate, semen, and Vaginal lubrication, vaginal fluids. Non-sexual transmission can occur from an infected mother to her infant during pregnancy, during childbirth by exposure to her blood or vaginal fluid, and through breast milk. Within these bodily fluids, HIV is present as both free virus particles and virus within infected White blood cell, immune cells. Research has s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
