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Topocuvirus
''Topocuvirus'' is a genus of viruses, in the family ''Geminiviridae''. Dicotyledonous plants serve as natural hosts. There is only one species in this genus: ''Tomato pseudo-curly top virus''. Diseases associated with this genus include: vein swelling, curling of the leaves and leaf distortion. Structure Viruses in ''Topocuvirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. The diameter is around 22 nm, with a length of 38 nm. Genomes are circular and non-segmented, around 2.86kb in length. Life cycle Viral replication is nuclear. Entry into the host cell is achieved by penetration into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export, and tubule-guided viral movement. Dicotyledonous plants serve as the natural host. The virus is transmitted via a vector (treehopper Treehoppers (more precisely typical treehoppe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geminiviridae
''Geminiviridae'' is a family of plant viruses that encode their genetic information on a circular genome of single-stranded (ss) DNA. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosaic, yellow mottle, leaf curling, stunting, streaks, reduced yields. They have single-stranded circular DNA genomes encoding genes that diverge in both directions from a virion strand origin of replication (i.e. geminivirus genomes are ambisense). According to the Baltimore classification they are considered class II viruses. It is the largest known family of single stranded DNA viruses. Mastrevirus and curtovirus Transmission (medicine), transmission is via various leafhopper species (e.g. maize streak virus and other African streak viruses are transmitted by ''Cicadulina mbila''), the only known topocuvirus species, ''Tomato pseudo-curly top virus'', is transmitted by the treehopper ''Micrutalis malleifera'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viruses
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Treehopper
Treehoppers (more precisely typical treehoppers to distinguish them from the Aetalionidae) and thorn bugs are members of the family (biology), family Membracidae, a group of insects related to the cicadas and the leafhoppers. About 3,200 species of treehoppers in over 400 genera are known.Treehoppers. Dr. Metcalf. NCSU Libraries. North Carolina State University. They are found on all continents except Antarctica; only five species are known from Europe. Individual treehoppers usually live for only a few months. Morphology Treehoppers, due to their unusual appearance, have long interested naturalists. They are best known for their enlarged and ornate pronotum, expanded into often fantastic shapes that enhance their camouflage or mimicry, often resembling Thorns, spines, and prickles, plant th ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
