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Mamavirus
Mamavirus is a large and complex virus in the Group I family ''Mimiviridae''. The virus is exceptionally large, and larger than many bacteria. Mamavirus and other mimiviridae belong to nucleocytoplasmic large DNA virus (NCLDVs) family. Mamavirus can be compared to the similar complex virus mimivirus; mamavirus was so named because it is similar to but larger than mimivirus. Discovery Mamavirus was first reported in September 2008. Like mimivirus, mamavirus was isolated from an amoeba in a cooling tower. The mimiviridae were not discovered until recently because of their size; when filtered the mimiviridae stay with the bacteria which led scientists to believe they were also bacteria. Mimivirus was first isolated in 1992 when scientists were looking for the cause of a pneumonia outbreak in Bradford, UK. Due to its size it was named ''Bradfordcoccus'' and put in a freezer with scientists thinking it was a bacterium. A decade later, Jean-Michel Claverie and Didier Raoult disc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sputnik Virophage
''Mimivirus-dependent virus Sputnik'' (from Russian "satellite") is a subviral agent that reproduces in amoeba cells that are already infected by a certain helper virus; Sputnik uses the helper virus's machinery for reproduction and inhibits replication of the helper virus. It is known as a virophage, in analogy to the term ''bacteriophage''. Viruses like Sputnik that depend on co-infection of the host cell by helper viruses are known as satellite viruses. At its discovery in a Paris water-cooling tower in 2008, Sputnik was the first known satellite virus that inhibited replication of its helper virus and thus acted as a parasite of that virus. In analogy, it was called a ''virophage''. Sputnik virophages were found infecting giant viruses of ''Mimiviridae'' group A. However, they are able to grow in amoebae infected by ''Mimiviridae'' of any of the groups A, B, and C. Virology Sputnik was first isolated in 2008 from a sample obtained from humans; it was harvested from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimivirus
''Mimivirus'' is a genus of giant viruses, in the family '' Mimiviridae''. Amoeba serve as their natural hosts. This genus contains a single identified species named ''Acanthamoeba polyphaga mimivirus'' (APMV). It also refers to a group of phylogenetically related large viruses. In colloquial speech, APMV is more commonly referred to as just "mimivirus". Mimivirus, short for "mimicking microbe", is so called to reflect its large size and apparent Gram-staining properties. Mimivirus has a large and complex genome compared with most other viruses. Until 2013, when a larger virus '' Pandoravirus'' was described, it had the largest capsid diameter of all known viruses. History APMV was discovered accidentally in 1992 within the amoeba '' Acanthamoeba polyphaga'', after which it is named, during research into legionellosis by researchers from Marseille and Leeds. The virus was observed in a Gram stain and mistakenly thought to be a Gram-positive bacterium. As a consequence it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimivirus
''Mimivirus'' is a genus of giant viruses, in the family '' Mimiviridae''. Amoeba serve as their natural hosts. This genus contains a single identified species named ''Acanthamoeba polyphaga mimivirus'' (APMV). It also refers to a group of phylogenetically related large viruses. In colloquial speech, APMV is more commonly referred to as just "mimivirus". Mimivirus, short for "mimicking microbe", is so called to reflect its large size and apparent Gram-staining properties. Mimivirus has a large and complex genome compared with most other viruses. Until 2013, when a larger virus '' Pandoravirus'' was described, it had the largest capsid diameter of all known viruses. History APMV was discovered accidentally in 1992 within the amoeba '' Acanthamoeba polyphaga'', after which it is named, during research into legionellosis by researchers from Marseille and Leeds. The virus was observed in a Gram stain and mistakenly thought to be a Gram-positive bacterium. As a consequence it was ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthamoeba Polyphaga
''Acanthamoeba'' is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats. ''Acanthamoeba'' has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, ''Acanthamoeba'' species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals. Distribution ''Acanthamoeba'' spp. are among the most prevalent protozoa found in the environment. They are distributed worldwide, and have been isolated from soil, air, sewage, seawater, chlorinated swimming pools, domestic tap water, bottled water, dental treatment units, hospitals, air-conditioning units, and contact lens cases. Additionally, they have been isolated from human skin, nasal cavities, throats, and intestines, as well as plants and other mammals. Role in disease Diseases caused by ''Acanthamoeba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage
A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. MS2) and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere. Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined. Viruses are the most abundant biological entity in the water column of the world's oceans, and the second largest component o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of 'junk' DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The International Human Genome Project reported the sequence of the genome for ''Homo sapiens'' in 200The Human Genome Project although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. With advancements in technology that could handle sequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthamoeba Castellanii
''Acanthamoeba'' is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats. ''Acanthamoeba'' has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, ''Acanthamoeba'' species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals. Distribution ''Acanthamoeba'' spp. are among the most prevalent protozoa found in the environment. They are distributed worldwide, and have been isolated from soil, air, sewage, seawater, chlorinated swimming pools, domestic tap water, bottled water, dental treatment units, hospitals, air-conditioning units, and contact lens cases. Additionally, they have been isolated from human skin, nasal cavities, throats, and intestines, as well as plants and other mammals. Role in disease Diseases caused by ''Acanthamoeba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthamoeba
''Acanthamoeba'' is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats. ''Acanthamoeba'' has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, ''Acanthamoeba'' species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals. Distribution ''Acanthamoeba'' spp. are among the most prevalent protozoa found in the environment. They are distributed worldwide, and have been isolated from soil, air, sewage, seawater, chlorinated swimming pools, domestic tap water, bottled water, dental treatment units, hospitals, air-conditioning units, and contact lens cases. Additionally, they have been isolated from human skin, nasal cavities, throats, and intestines, as well as plants and other mammals. Role in disease Diseases caused by ''Acanthamoeba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DsDNA Viruses
A DNA virus is a virus that has a genome made of deoxyribonucleic acid (DNA) that is replicated by a DNA polymerase. They can be divided between those that have two strands of DNA in their genome, called double-stranded DNA (dsDNA) viruses, and those that have one strand of DNA in their genome, called single-stranded DNA (ssDNA) viruses. dsDNA viruses primarily belong to two realms: ''Duplodnaviria'' and ''Varidnaviria'', and ssDNA viruses are almost exclusively assigned to the realm ''Monodnaviria'', which also includes some dsDNA viruses. Additionally, many DNA viruses are unassigned to higher taxa. Reverse transcribing viruses, which have a DNA genome that is replicated through an RNA intermediate by a reverse transcriptase, are classified into the kingdom '' Pararnavirae'' in the realm '' Riboviria''. DNA viruses are ubiquitous worldwide, especially in marine environments where they form an important part of marine ecosystems, and infect both prokaryotes and eukaryotes. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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