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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, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammaretrovirus Core Encapsidation Signal
The Gammaretrovirus core encapsidation signal is an RNA element known to be essential for stable dimerisation and efficient genome packaging during virus assembly. Dimerisation of the viral RNA genomes is proposed to act as an RNA conformational switch which exposes conserved UCUG elements and enables efficient genome encapsidation. The structure of this element is composed of three stem-loop Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence wh ...s. Two of the stem-loops called SL-C and SL-D form a single co-axial extend helix. See also * Bacteriophage pRNA References External links * Cis-regulatory RNA elements {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibbon Ape Leukemia Virus
Gibbon-ape leukemia virus (GaLV) is an oncogenic, type C retrovirus that has been isolated from primate neoplasms, including the white-handed gibbon and woolly monkey. The virus was identified as the etiological agent of hematopoietic neoplasms, leukemias, and immune deficiencies within gibbons in 1971, during the epidemic of the late 1960s and early 1970s. Epidemiological research into the origins of GaLV has developed two hypotheses for the virus' emergence. These include cross-species transmission of the retrovirus present within a species of East Asian rodent or bat, and the inoculation or blood transfusion of a MbRV-related virus into captured gibbons populations housed at medical research institutions. The virus was subsequently identified in captive gibbon populations in Thailand, the US and Bermuda. GaLV is transmitted horizontally by contact with excretory products of infected gibbons. However, it is also hypothesised to be vertically transmitted via parent-progeny transm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murine Leukemia Virus
The murine leukemia viruses (MLVs or MuLVs) are retroviruses named for their ability to cause cancer in murine (mouse) hosts. Some MLVs may infect other vertebrates. MLVs include both exogenous and endogenous viruses. Replicating MLVs have a positive sense, single-stranded RNA (ssRNA) genome that replicates through a DNA intermediate via the process of reverse transcription. Classification The murine leukemia viruses are group/type VI retroviruses belonging to the gammaretroviral genus of the Retroviridae family. The viral particles of replicating MLVs have C-type morphology as determined by electron microscopy. The MLVs include both exogenous and endogenous viruses. Exogenous forms are transmitted as new infections from one host to another. The Moloney, Rauscher, Abelson and Friend MLVs, named for their discoverers, are used in cancer research. Endogenous MLVs are integrated into the host's germ line and are passed from one generation to the next. Stoye and Coffin h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murine Leukemia Virus
The murine leukemia viruses (MLVs or MuLVs) are retroviruses named for their ability to cause cancer in murine (mouse) hosts. Some MLVs may infect other vertebrates. MLVs include both exogenous and endogenous viruses. Replicating MLVs have a positive sense, single-stranded RNA (ssRNA) genome that replicates through a DNA intermediate via the process of reverse transcription. Classification The murine leukemia viruses are group/type VI retroviruses belonging to the gammaretroviral genus of the Retroviridae family. The viral particles of replicating MLVs have C-type morphology as determined by electron microscopy. The MLVs include both exogenous and endogenous viruses. Exogenous forms are transmitted as new infections from one host to another. The Moloney, Rauscher, Abelson and Friend MLVs, named for their discoverers, are used in cancer research. Endogenous MLVs are integrated into the host's germ line and are passed from one generation to the next. Stoye and Coffin h ... [...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. Once inside the 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'' (backwards). 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. Although retroviruses have different subfamilies, they have three basic groups: the oncoretroviruses (oncogenic retroviruses), the lentiviruses (slow retroviruses) and the spumaviruses (foamy viruses). The oncoretroviruses are able to cause cancer in some species, the lentivirus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chick Syncytial Virus
The ''chick syncytial virus'' is a virus in the genus ''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. Introductio ...''. References Gammaretroviruses {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feline Leukemia Virus
Feline leukemia virus (FeLV) is a retrovirus that infects cats. FeLV can be transmitted from infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal's immune system, the virus weakens the cat's immune system, which can lead to diseases which can be lethal. Because FeLV is cat-to-cat contagious, FeLV+ cats should only live with other FeLV+ cats. FeLV is categorized into four subgroups, A, B, C and T. An infected cat has a combination of FeLV-A and one or more of the other subgroups. Symptoms, prognosis and treatment are all affected by subgroup. FeLV+ cats often have a shorter lifespan, but can still live "normal", healthy lives. Signs and symptoms The signs and symptoms of infection with feline leukemia virus are quite varied and include loss of appetite, poor coat condition, anisocoria (uneven pupils), infections of the skin, bladder, and respiratory tract, oral disease, seizures, lymphadenopathy (swollen lymph nodes), skin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feline Leukemia Virus
Feline leukemia virus (FeLV) is a retrovirus that infects cats. FeLV can be transmitted from infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal's immune system, the virus weakens the cat's immune system, which can lead to diseases which can be lethal. Because FeLV is cat-to-cat contagious, FeLV+ cats should only live with other FeLV+ cats. FeLV is categorized into four subgroups, A, B, C and T. An infected cat has a combination of FeLV-A and one or more of the other subgroups. Symptoms, prognosis and treatment are all affected by subgroup. FeLV+ cats often have a shorter lifespan, but can still live "normal", healthy lives. Signs and symptoms The signs and symptoms of infection with feline leukemia virus are quite varied and include loss of appetite, poor coat condition, anisocoria (uneven pupils), infections of the skin, bladder, and respiratory tract, oral disease, seizures, lymphadenopathy (swollen lymph nodes), skin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koala Retrovirus
''Koala retrovirus'' (KoRV) is a retrovirus that is present in many populations of koalas. It has been implicated as the agent of koala immune deficiency syndrome (KIDS), an AIDS-like immunodeficiency that leaves infected koalas more susceptible to infectious disease and cancers. The virus is thought to be a recently introduced exogenous virus that is also integrating into the koala genome ( becoming endogenous). Thus the virus can transmit both horizontally (from animal to animal in the classic sense) and vertically (from parent to offspring as a gene). The horizontal modes of transmission are not well defined but are thought to require close contact. ''Koala retrovirus'' was initially described as a novel endogenous retrovirus found within the koala genome and in tissues as free virions. Viral DNA sequence analysis showed intact open reading frames and pathogenic DNA motifs strongly suggesting that KoRV is an active replicating endogenous retrovirus that can also produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woolly Monkey Sarcoma Virus
Woolly monkey sarcoma virus (WMSV), with synonym Simian sarcoma virus (often abbreviated by SSV, but this may also stand for some species called ' Sulfolobus spindle-shaped virus', that belong to different genera in family Fuselloviridae) is a species of gammaretrovirus that infects primates. First isolation was from a fibrosarcoma in a woolly monkey The woolly monkeys are the genus ''Lagothrix'' of New World monkeys, usually placed in the family Atelidae. Both species in this genus originate from the rainforests of South America. They have prehensile tails and live in relatively large soc ... (genus ''Lagothrix''). For its reproduction the virus needs a helper or associated virus which is called Simian sarcoma associated virus (SSAV). Simian sarcoma virus (SSV) and simian sarcoma associated virus (SSAV) See ...
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Lentiviral Vector In Gene Therapy
Lentiviral vectors in gene therapy is a method by which genes can be inserted, modified, or deleted in organisms using lentiviruses. Lentiviruses are a family of viruses that are responsible for diseases like AIDS, which infect by inserting DNA into their host cells' genome. Many such viruses have been the basis of research using viruses in gene therapy, but the lentivirus is unique in its ability to infect non-dividing cells, and therefore has a wider range of potential applications. Lentiviruses can become endogenous (ERV), integrating their genome into the host germline genome, so that the virus is henceforth inherited by the host's descendants. To be effective in gene therapy, there must be insertion, alteration and/or removal of host cell genes. To do this, scientists use the lentivirus' mechanisms of infection to achieve a desired outcome to gene therapy. To understand the capabilities of a lentiviral vector, one has to consider the biology of the infection process. The le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endogenous Retroviruses
Endogenous retroviruses (ERVs) are endogenous viral elements in the genome that closely resemble and can be derived from retroviruses. They are abundant in the genomes of jawed vertebrates, and they comprise up to 5–8% of the human genome (lower estimates of ~1%). ERVs are a vertically inherited proviral sequence and a subclass of a type of gene called a transposon, which can normally be packaged and moved within the genome to serve a vital role in gene expression and in regulation. ERVs however lack most transposon functions, are typically not infectious and are often defective genomic remnants of the retroviral replication cycle. They are distinguished as germline provirus retroelements due to their integration and reverse-transcription into the nuclear genome of the host cell. Researchers have suggested that retroviruses evolved from a type of transposon called a retrotransposon, a Class I element; these genes can mutate and instead of moving to another location in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
