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Cassava Brown Streak Virus
''Cassava brown streak virus'' is a species of positive-strand RNA viruses in the genus ''Ipomovirus'' and family '' Potyviridae'' which infects plants. Member viruses are unique in their induction of pinwheel, or scroll-shaped inclusion bodies Inclusion bodies are aggregates of specific types of protein found in neurons, a number of tissue cells including red blood cells, bacteria, viruses, and plants. Inclusion bodies of aggregations of multiple proteins are also found in muscle cells ... in the cytoplasm of infected cells. Cylindrical inclusion bodies include aggregations of virus-encoded helicase proteins. These inclusion bodies are thought to be sites of viral replication and assembly, making then an important factor in the viral lifecycle. Viruses from both the species ''Cassava brown streak virus'' and ''Ugandan cassava brown streak virus'' (UCBSV), lead to the development of Cassava Brown Streak Disease (CBSD) within cassava plants. History ''Cassava brown streak vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive-strand RNA Virus
Positive-strand RNA viruses (+ssRNA viruses) are a group of related viruses that have positive-sense, single-stranded genomes made of ribonucleic acid. The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated into viral proteins by the host cell's ribosomes. Positive-strand RNA viruses encode an RNA-dependent RNA polymerase (RdRp) which is used during replication of the genome to synthesize a negative-sense antigenome that is then used as a template to create a new positive-sense viral genome. Positive-strand RNA viruses are divided between the phyla ''Kitrinoviricota'', ''Lenarviricota'', and ''Pisuviricota'' (specifically classes ''Pisoniviricetes'' and '' Stelpavirictes'') all of which are in the kingdom '' Orthornavirae'' and realm '' Riboviria''. They are monophyletic and descended from a common RNA virus ancestor. In the Baltimore classification system, +ssRNA viruses belong to Group IV. Positive-sense RNA viruses include pathogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ipomovirus
''Ipomovirus'' is a genus of positive-strand RNA viruses in the family ''Potyviridae''. Member viruses infect plants and are transmitted by whiteflies (''Bemisia tabaci''). The name of the genus is derived from ''Ipomoea'' – the generic name of sweet potato. There are seven species in this genus. Structure Viruses in genus ''Ipomovirus'' are non-enveloped, with flexuous and filamentous geometries. The diameter is around 12–15 nm, and may have a variety of lengths depending on the species (for single segmented species lengths of around 650–900 nm, or for double segmented species 200–300 nm and 500–600 nm). The capsid has helical symmetry with a pitch of 3.4 nm. They induce characteristic inclusion bodies (pinwheels) within infected plant cells. Genome The genome is either monpartite or bipartite depending on the species. Member viruses have linear, single stranded RNA genome of positive polarity about 10-11 kilobases in length. The 3’ terminus h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyviridae
''Potyviridae'' is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family has 12 genera and 235 species, three of which are unassigned to a genus. Structure Potyvirid virions are nonenveloped, flexuous filamentous, rod-shaped particles. The diameter is around 12–15 nm, with a length of 200–300 nm. Genome Genomes are linear and usually nonsegmented, around 8–12kb in length, consisting of positive-sense RNA, which is surrounded by a protein coat made up of a single viral encoded protein called a capsid. All induce the formation of virus inclusion bodies called cylindrical inclusions (‘pinwheels’) in their hosts. These consist of a single protein (about 70 kDa) made in their hosts from a single viral genome product. Member viruses encode large polypeptides that are cleaved into mature proteins. In 5'–3' order these proteins are * P1 (a serine protease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclusion Bodies
Inclusion bodies are aggregates of specific types of protein found in neurons, a number of tissue cells including red blood cells, bacteria, viruses, and plants. Inclusion bodies of aggregations of multiple proteins are also found in muscle cells affected by inclusion body myositis and hereditary inclusion body myopathy. Inclusion bodies in neurons may be accumulated in the cytoplasm or nucleus, and are associated with many neurodegenerative diseases. Inclusion bodies in neurodegenerative diseases are aggregates of misfolded proteins (aggresomes) and are hallmarks of many of these diseases, including Lewy bodies in Lewy body dementias, and Parkinson's disease, neuroserpin inclusion bodies called Collins bodies in familial encephalopathy with neuroserpin inclusion bodies, inclusion bodies in Huntington's disease, Papp-Lantos inclusions in multiple system atrophy, and various inclusion bodies in frontotemporal dementia including Pick bodies. Bunina bodies in motor neurons are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassava Brown Streak Virus Disease
Cassava brown streak virus disease (CBSD) is a damaging disease of cassava plants, and is especially troublesome in East Africa. It was first identified in 1936 in Tanzania, and has spread to other coastal areas of East Africa, from Kenya to Mozambique. Recently, it was found that two distinct viruses are responsible for the disease: cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Both have (+)ss RNA genomes, belong to the genus ''Ipomovirus'' in the family ''Potyviridae,'' and produce generally similar symptoms in infected plants. Root rot renders the cassava tuber inedible, resulting in severe loss of economic value; therefore, current research focuses on achieving cultivars that do not develop the necrotic rot. This disease is considered to be the biggest threat to food security in coastal East Africa and around the eastern lakes. Symptoms CBSD is characterized by severe chlorosis and necrosis on infected leaves, giving them a yellowish, mottl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyvirus Virion (1)
''Potyvirus'' is a genus of positive-strand RNA viruses in the family '' Potyviridae''. Plants serve as natural hosts. The genus is named after member virus '' potato virus Y''. Potyviruses account for about thirty percent of the currently known plant viruses. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural, and ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily ''Aphidinae'' (genera ''Macrosiphum'' and ''Myzus''). The genus contains 190 species. Virology Structure The virion is non-enveloped with a flexuous and filamentous nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains around 2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4 nm. Genome The genome is a linear, positive-sense, single-stranded RNA ranging in size from 9,000–12,000 nucleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyvirus Genome (1)
''Potyvirus'' is a genus of positive-strand RNA viruses in the family '' Potyviridae''. Plants serve as natural hosts. The genus is named after member virus '' potato virus Y''. Potyviruses account for about thirty percent of the currently known plant viruses. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural, and ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily ''Aphidinae'' (genera ''Macrosiphum'' and ''Myzus''). The genus contains 190 species. Virology Structure The virion is non-enveloped with a flexuous and filamentous nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains around 2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4 nm. Genome The genome is a linear, positive-sense, single-stranded RNA ranging in size from 9,000–12,000 nucleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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