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Human Betaherpesvirus 6A
''Human betaherpesvirus 6A'' (HHV-6A) is a species of virus in the genus ''Roseolovirus'', subfamily ''Betaherpesvirinae'', family ''Herpesviridae'', and order ''Herpesvirales''. Taxonomy In 1992 the two variants were recognised within Human herpesvirus 6 on the basis of differing restriction endonuclease cleavages, monoclonal antibody reactions, and growth patterns. In 2012 these two variants were officially recognised as distinct species by the International Committee on Taxonomy of Viruses and named ''Human betaherpesvirus 6A'' and ''Human betaherpesvirus 6B''. Despite now being recognised as paraphyly, paraphyletic, the name Human herpesvirus 6 still sees usage in clinical contexts. Pathology ''Human betaherpesvirus 6A'' affects humans and includes several adult-derived strains. Its disease spectrum is not well defined, although it is thought by some to be more neurovirulent than ''Human betaherpesvirus 6B''. References {{Taxonbar, from=Q24808739 Betaherpesv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roseolovirus
''Roseolovirus'' is a genus of viruses in the order ''Herpesvirales'', in the family ''Herpesviridae'', in the subfamily ''Betaherpesvirinae''. There are currently six species in this genus. Diseases associated with this genus include: HHV-6: sixth disease (roseola infantum, exanthema subitum); HHV-7: symptoms analog to the 'sixth disease'. Species The genus consists of the following six species: * ''Human betaherpesvirus 7'' * ''Human betaherpesvirus 6A'' * ''Human betaherpesvirus 6B'' * ''Macacine betaherpesvirus 9'' * ''Murid betaherpesvirus 3'' * ''Suid betaherpesvirus 2'' Structure Viruses in ''Roseolovirus'' are enveloped, with icosahedral, spherical to pleomorphic, and round geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented, around 200kb in length. Life cycle Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of the viral glycoproteins to host receptors, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betaherpesvirinae
''Betaherpesvirinae'' is a subfamily of viruses in the order ''Herpesvirales'' and in the family ''Herpesviridae''. Mammals serve as natural hosts. There are 26 species in this subfamily, divided among 5 genera. Diseases associated with this subfamily include: human cytomegalovirus (HHV-5): congenital CMV infection; HHV-6: 'sixth disease' (also known as ''roseola infantum'' or ''exanthem subitum''); HHV-7: symptoms analogous to the 'sixth disease'. Genera ''Betaherpesvirinae'' consists of the following five genera: * ''Cytomegalovirus'' * ''Muromegalovirus'' * '' Proboscivirus'' * ''Quwivirus'' * ''Roseolovirus'' Structure Viruses in ''Betaherpesvirinae'' are enveloped, with icosahedral, spherical to pleomorphic, and Round geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented, around 140-240kb in length. Life cycle Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpesviridae
''Herpesviridae'' is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ''ἕρπειν'' ( 'to creep'), referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster ( shingles). In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established ''Herpesvirus'' as a genus with 23 viruses among four groups. As of 2020, 115 species are recognized, all but one of which are in one of the three subfamilies. Herpesviruses can cause both latent and lytic infections. Nine herpesvirus types are known to primarily infect humans, at least five of which – herpes simplex viruses 1 and 2 (HSV-1 and HSV-2, also known as HHV-1 and HHV-2; both of which can cause orolabial herpes and genital herpes), varicella zoster virus (or HHV-3; the cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpesvirales
The ''Herpesvirales'' is an order of dsDNA viruses (Baltimore group I) with animal hosts, characterised by a common morphology consisting of an icosahedral capsid enclosed in a glycoprotein-containing lipid envelope. Common infections in humans caused by members of this order include cold sores, genital herpes, chickenpox, shingles, and glandular fever. ''Herpesvirales'' is the sole order in the class ''Herviviricetes'', which is the sole class in the phylum ''Peploviricota''. Virology Morphology All members of the order have a virion structure that consists of a DNA core surrounded by an icosahedral capsid composed of 12 pentavalent and 150 hexavalent capsomeres (T = 16). The capsid has a diameter of ~110 nanometers (nm) and is embedded in a proteinaceous matrix called the tegument, which in its turn is enclosed by a glycoprotein-containing lipid envelope with a diameter of about 200 nm. The DNA genome is linear and double stranded, with sizes in the range 125–290 kb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Herpesvirus 6
Human herpesvirus 6 (HHV-6) is the common collective name for ''human betaherpesvirus 6A'' (HHV-6A) and ''human betaherpesvirus 6B'' (HHV-6B). These closely related viruses are two of the nine known herpesviruses that have humans as their primary host. HHV-6A and HHV-6B are double-stranded DNA viruses within the ''Betaherpesvirinae'' subfamily and of the genus ''Roseolovirus''. HHV-6A and HHV-6B infect almost all of the human populations that have been tested. HHV-6A has been described as more neurovirulent, and as such is more frequently found in patients with neuroinflammatory diseases such as multiple sclerosis. HHV-6 (and HHV-7) levels in the brain are also elevated in people with Alzheimer's disease. HHV-6B primary infection is the cause of the common childhood illness exanthema subitum (also known as roseola infantum or sixth disease). It is passed on from child to child. It is uncommon for adults to contract this disease as most people have had it by kindergarten, and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Committee On Taxonomy Of Viruses
The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclatures for viruses. The ICTV has developed a universal taxonomic scheme for viruses, and thus has the means to appropriately describe, name, and classify every virus that affects living organisms. The members of the International Committee on Taxonomy of Viruses are considered expert virologists. The ICTV was formed from and is governed by the Virology Division of the International Union of Microbiological Societies. Detailed work, such as delimiting the boundaries of species within a family, typically is performed by study groups of experts in the families. History The International Committee on Nomenclature of Viruses (ICNV) was established in 1966, at the International Congress for Microbiology in Moscow, to standardize the naming of viruses. The ICVN published its first report in 1971. For viruses infecting vertebrates, the first report included ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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