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Totivirus
''Totivirus'' is a genus of double-stranded RNA viruses in the family ''Totiviridae''. Fungi serve as natural hosts. The name of the group derives from Latin ''toti'' which means undivided or whole. There are seven species in this genus. Structure Viruses in the genus ''Totivirus'' are non-enveloped, with icosahedral symmetry, and T=2 architecture. The diameter is around 40 nm. Genome Totiviruses have a genome of 4700–6700 nucleotides in length and only a single copy of the genome is present in the particle. The nucleic acid content of a totivirus capsid is usually of one segment but can also contain three or four segments of linear double stranded RNA. The genome contains two large overlapping open reading frames (ORFs). These open reading frames (ORFs) code for a capsid protein (CP) and an RNA-dependent RNA polymerase (RdRp). The 5' end of the positive strand of the dsRNA genome has no cap and is very structured. Totiviruses contain a long 5' untranslated region (5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Totiviridae
''Totiviridae'' is a family of double-stranded RNA viruses. Giardia lamblia, leishmania, trichomonas vaginalis, and fungi serve as natural hosts. The name of the group derives from Latin ''toti'' which means undivided or whole. There are 28 species in this family, assigned to 5 genera. Structure Viruses in the family ''Totiviridae'' are non-enveloped, double-stranded RNA viruses with icosahedral geometries, and T=2 symmetry. The virion consists of a single capsid protein and is about 40 nanometers in diameter. Genome The genome is composed of a monopartite, linear double-stranded RNA molecule of 4.6–6.7 kilobases. It contains two overlapping open reading frames (ORF) – ''gag'' and ''pol –'' which respectively encode the capsid protein and the RNA-dependent RNA polymerase. Some totiviruses contain a third small potential ORF. Life cycle Viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Totiviridae Genome
''Totiviridae'' is a family of double-stranded RNA viruses. Giardia lamblia, leishmania, trichomonas vaginalis, and fungi serve as natural hosts. The name of the group derives from Latin ''toti'' which means undivided or whole. There are 28 species in this family, assigned to 5 genera. Structure Viruses in the family ''Totiviridae'' are non-enveloped, double-stranded RNA viruses with icosahedral geometries, and T=2 symmetry. The virion consists of a single capsid protein and is about 40 nanometers in diameter. Genome The genome is composed of a monopartite, linear double-stranded RNA molecule of 4.6–6.7 kilobases. It contains two overlapping open reading frames (ORF) – ''gag'' and ''pol –'' which respectively encode the capsid protein and the RNA-dependent RNA polymerase. Some totiviruses contain a third small potential ORF. Life cycle Viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces Cerevisiae Virus L-A
''Saccharomyces cerevisiae virus L-A'', also called L-A helper virus, is a member of the ''Totiviridae'' family of viruses found primarily in ''Saccharomyces cerevisiae''. Its discovery in the 1970s was the main starting point of research on yeast virology. It is a ~4.6 kb double-stranded RNA virus with no extracellular phase and so is inherited through vertical cytoplasmic transmission. Additionally, in many strains of the yeast, it is found along with another virus called the M virus (or "M dsRNA", "Saccharomyces cerevisiae killer virus"), known to encode the killer toxin in many ''S. cerevisiae'' strains which confers the ability to kill neighboring sensitive cells that do not harbor the virus. It is indeed for this reason the virus is referred to as a helper virus, due to the M genome's dependence on it for its own survival and replication. (More recently, the M dsRNA is described as a satellite RNA.) A Yeast lineage with a M/killer virus is known as a " killer strain". The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word toxic. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). Toxins are largely secondary metabolites, which are organic compounds that are not directly involved in an organism's growth, development, or reproduction, instead often aiding it in matters of defense. Terminology Toxins are often distinguished from other chemical agents strictly based on their biological origin. Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ustilago Maydis Virus H1
''Ustilago'' is a genus of approximately 200 smut fungi parasitic on grasses. Uses ''Ustilago maydis'' is eaten as a traditional Mexican food in many parts of the country, and is even available canned. Farmers have even been known to spread the spores around on purpose to create more of the fungus. It is known in central Mexico by the Nahuatl name huitlacoche. Peasants in other parts of the country call it "hongo de maíz," i.e. "maize fungus." The genome of '' U. maydis'' has beesequenced See also * Corn smut References External links *Ustilago' at Index Fungorum ''Index Fungorum'' is an international project to index all formal names ( scientific names) in the fungus kingdom. the project is based at the Royal Botanic Gardens, Kew, one of three partners along with Landcare Research and the Institute of M ... Ustilaginomycotina Fungal plant pathogens and diseases Basidiomycota genera {{fungus-plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuber Aestivum Virus 1
Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing season, and as a means of asexual reproduction. ''Stem tubers'' form thickened rhizomes (underground stems) or stolons (horizontal connections between organisms); well known species with stem tubers include the potato and yam. Some writers also treat modified lateral roots (''root tubers'') under the definition; these are found in sweet potatoes, cassava, and dahlias. Terminology The term originates from the Latin , meaning "lump, bump, swelling". Some writers define the term "tuber" to mean only structures derived from stems; others use the term for structures derived from stems or roots., p. 124 Stem tubers A stem tuber forms from thickened rhizomes or stolons. The top sides of the tuber produce shoots that grow into typical stems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces Cerevisiae Virus LBCLa
''Saccharomyces'' is a genus of fungi that includes many species of yeasts. ''Saccharomyces'' is from Greek σάκχαρον (sugar) and μύκης (fungus) and means ''sugar fungus''. Many members of this genus are considered very important in food production. It is known as the brewer's yeast or baker's yeast. They are unicellular and saprotrophic fungi. One example is ''Saccharomyces cerevisiae'', which is used in making bread, wine, and beer, and for human and animal health. Other members of this genus include the wild yeast ''Saccharomyces paradoxus'' that is the closest relative to ''S. cerevisiae'', ''Saccharomyces bayanus'', used in making wine, and ''Saccharomyces cerevisiae'' var. ''boulardii'', used in medicine. Morphology Colonies of ''Saccharomyces'' grow rapidly and mature in three days. They are flat, smooth, moist, glistening or dull, and cream in color. The inability to use nitrate and ability to ferment various carbohydrates are typical characteristics of ''Sacc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smut (fungus)
The smuts are multicellular fungi characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled, and dust-like teliospores. They are mostly Ustilaginomycetes (phylum Basidiomycota) and can cause plant disease. The smuts are grouped with the other basidiomycetes because of their commonalities concerning sexual reproduction. Smuts are cereal and crop pathogens that most notably affect members of the grass family (Poaceae) and sedges (Cyperaceae). Economically important hosts include maize, barley, wheat, oats, sugarcane, and forage grasses. They eventually hijack the plants' reproductive systems, forming galls which darken and burst, releasing fungal teliospores which infect other plants nearby. Before infection can occur, the smuts need to undergo a successful mating to form dikaryotic hyphae (two haploid cells fuse to form a dikaryon). Wild rice smut ''Ustilago esculenta'' is a species of fungus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces Cerevisiae
''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been originally isolated from the skin of grapes. It is one of the most intensively studied eukaryotic model organisms in molecular biology, molecular and cell biology, much like ''Escherichia coli'' as the model bacteria, bacterium. It is the microorganism behind the most common type of fermentation (biochemistry), fermentation. ''S. cerevisiae'' cells are round to ovoid, 5–10 micrometre, μm in diameter. It reproduces by budding. Many proteins important in human biology were first discovered by studying their Homology (biology), homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. ''S. cerevisiae'' is currently the only yeast cell known to have Berkeley body, Berkeley bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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