|
Ribozyviria
''Ribozyviria'' is a realm of satellite nucleic acids. Established in ICTV TaxoProp 2020.012D, the realm is named after the presence of genomic and antigenomic ribozymes of the ''Deltavirus'' type. Additional common features include a rod-like structure, a RNA-binding "delta antigen" encoded in the genome, and animal hosts. Furthermore, the size range of the genomes of these viruses is between around 1547–1735nt, they encode a hammerhead ribozyme or a hepatitis delta virus ribozyme, and their coding capacity only involves one conserved protein. Most lineages of this realm are poorly understood, the notable exception being members of the genus ''Deltavirus'', the causal agents of Hepatitis D in humans. This realm of viruses have an unclear origin. They may have derived from retrozymes (a family of retrotransposons) or one of the other groups of mobile genetic elements that descended from retrozymes (i.e. viroids and satellites). But it was also proposed that they may have orig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realm (virology)
In virology, realm is the highest taxonomic rank established for viruses by the International Committee on Taxonomy of Viruses (ICTV), which oversees virus taxonomy. Six virus realms are recognized and united by specific highly conserved traits: * ''Adnaviria'', which contains archaeal filamentous viruses with A-form double-stranded (ds) DNA genomes encoding a unique alpha-helical major capsid protein; * ''Duplodnaviria'', which contains all dsDNA viruses that encode the HK97-fold major capsid protein; * ''Monodnaviria'', which contains all single-stranded DNA (ssDNA) viruses that encode a HUH superfamily endonuclease and their descendants; * '' Riboviria'', which contains all RNA viruses that encode RNA-dependent RNA polymerase and all viruses that encode reverse transcriptase; * ''Ribozyviria'', which contains hepatitis delta-like viruses with circular, negative-sense ssRNA genomes; * and ''Varidnaviria'', which contains all dsDNA viruses that encode a vertical jelly rol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrozyme
Retrozymes are a family of retrotransposons first discovered in the genomes of plants but now also known in genomes of animals. Retrozymes contain a hammerhead ribozyme (HHR) in their sequences (and so the name ''retrozyme'' is a combination of ''retrotransposon'' and ''hammerhead ribozyme''), although they do not possess any coding regions. Retrozymes are nonautonomous retroelements, and so borrow proteins from other elements to move into new regions of a genome. Retrozymes are actively transcribed into covalently closed circular RNAs (circRNAs or cccRNAs) and are detected in both polarities, which may indicate the use of rolling circle replication in their lifecycle. The genomic structure of a retrozyme in plants involves a central non-coding region that may stretch about 300–600nt flanked by long terminal repeats about 300–400nt containing the HHR motif. They also have two sequences (a primer binding site (PBS) complementary to the tRNA-Met sequence and a poly-purine tract (PP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis D
Hepatitis D is a type of viral hepatitis caused by the hepatitis delta virus (HDV). HDV is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a satellite (a type of subviral agent) because it can propagate only in the presence of the hepatitis B virus (HBV). Transmission of HDV can occur either via simultaneous infection with HBV (coinfection) or superimposed on chronic hepatitis B or hepatitis B carrier state (superinfection). HDV infecting a person with chronic hepatitis B (superinfection) is considered the most serious type of viral hepatitis due to its severity of complications. These complications include a greater likelihood of experiencing liver failure in acute infections and a rapid progression to liver cirrhosis, with an increased risk of developing liver cancer in chronic infections. In combination with hepatitis B virus, hepatitis D has the highest fatality rate of all the hepatitis infections, at 20%. A recent estimate from 2020 sugges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltavirus
Hepatitis D is a type of viral hepatitis caused by the hepatitis delta virus (HDV). HDV is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a satellite (a type of subviral agent) because it can propagate only in the presence of the hepatitis B virus (HBV). Transmission of HDV can occur either via simultaneous infection with HBV (coinfection) or superimposed on chronic hepatitis B or hepatitis B carrier state (superinfection). HDV infecting a person with chronic hepatitis B (superinfection) is considered the most serious type of viral hepatitis due to its severity of complications. These complications include a greater likelihood of experiencing liver failure in acute infections and a rapid progression to liver cirrhosis, with an increased risk of developing liver cancer in chronic infections. In combination with hepatitis B virus, hepatitis D has the highest fatality rate of all the hepatitis infections, at 20%. A recent estimate from 2020 suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daletvirus
''Daletvirus'' is a genus of viruses in the Realm (virology), realm ''Ribozyviria'', containing the single species ''Daletvirus boae''. Host ''Boa constrictor'' and the white-eyed python (''Liasis mackloti savuensis'') serve as its hosts. File:BoaConstrictor.JPG, ''B. constrictor'' File:Liasis mackloti savuensis 3.jpg, ''L. mackloti savuensis'' References Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dalvirus
''Dalvirus'' is a genus of viruses in the realm ''Ribozyviria'', containing the single species ''Dalvirus anatis''. Hosts The grey teal (''Anas gracilis The grey teal (''Anas gracilis'') is a dabbling duck found in open wetlands in Australia and New Zealand. Description It can be identified due to the presence of a crimson coloured iris in its eyes.Winter, M. (2018). Grey Teal. Wilderness Mag ...''), chestnut teal ('' A. castanea''), and Pacific black duck ('' A. superciliosa'') serve as its hosts. File:Anas gracilis - Bushell's Lagoon.jpg, ''A. gracilis'' File:Male chestnut teal.jpg, ''A. castanea'' File:Pacific Black Duck JCB.jpg, ''A. superciliosa'' References Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daazvirus
''Daazvirus'' is a genus of viruses in the realm ''Ribozyviria'', containing the single species ''Daazvirus cynopis''. Host The Chinese fire belly newt (''Cynops orientalis The Chinese fire belly newt (''Cynops orientalis'') is a small () black newt, with bright-orange aposematic coloration on their ventral sides. ''C. orientalis'' is commonly seen in pet stores, where it is frequently confused with the Japanese f ...'') serves as its host. File:Cynops orientalis.JPG, ''C. orientalis'' References Virus genera Monotypic genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dagazvirus
''Dagazvirus'' is a genus of viruses in the realm ''Ribozyviria ''Ribozyviria'' is a realm of satellite nucleic acids. Established in ICTV TaxoProp 2020.012D, the realm is named after the presence of genomic and antigenomic ribozymes of the ''Deltavirus'' type. Additional common features include a rod-like s ...'', containing the single species ''Dagazvirus schedorhinotermitis''. It is the only species within its realm known to be hosted by an invertebrate animal; the termite '' Schedorhinotermes intermedius''. References Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite (biology)
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV). Most viruses have the capability to use host enzymes or their own replication machinery to independently replicate their own viral RNA. Satellites, in contrast, are completely dependent on a helper virus for replication. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deevirus
''Deevirus'' is a genus of viruses in the realm ''Ribozyviria'', containing the single species ''Deevirus actinopterygii''. Various ray-finned fishes (Actinopterygii Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...) serve as its hosts. References Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anas Castanea
The chestnut teal (''Anas castanea'') is a dabbling duck found in Australia. It is protected under the National Parks and Wildlife Act 1974. Taxonomy The chestnut teal was described by the English naturalist Thomas Campbell Eyton in 1838 under the binomial name ''Mareca castanea''. The specific epithet ''castanea'' is from the Latin ''castaneus'' for "chestnut-coloured" or "chestnut-brown". A large molecular phylogentic study that compared mitochondrial DNA sequences from ducks, geese and swans in the family Anatidae found that the chestnut teal is a sister species to the Sunda teal (''Anas gibberifrons'') that is endemic to Indonesia. Description The chestnut teal is darker and a slightly bigger bird than the grey teal. The male has a distinctive green coloured head and mottled brown body. The female has a brown head and mottled brown body. The female is almost identical in appearance to the grey teal. The female chestnut teal has a loud penetrating "laughing" quack repeated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anas Superciliosa
The Pacific black duck (''Anas superciliosa''), commonly known as the PBD, is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the gray duck in New Zealand, where it is also known by its Maori name, . Taxonomy The Pacific black duck was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's ''Systema Naturae''. He placed it with all the other ducks, geese and swans in the genus ''Anas'' and coined the binomial name ''Anas superciliosa''. Gmelin based his description on the "Supercilious duck" that had been described in 1785 by the English ornithologist John Latham in his ''A General Synopsis of Birds''. The naturalist Joseph Banks had provided Latham with a water-colour drawing of the duck by Georg Forster who had accompanied Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
