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Viral Hemorrhagic Septicemia
Viral hemorrhagic septicemia (VHS) is a deadly infectious fish disease caused by Viral hemorrhagic septicemia virus. It afflicts over 50 species of freshwater and marine fish in several parts of the Northern Hemisphere. Different strains of the virus occur in different regions, and affect different species. There are no signs that the disease affects human health. VHS is also known as Egtved disease, and the virus as Egtved virus. Historically, VHS was associated mostly with freshwater salmonids in western Europe, documented as a pathogenic disease among cultured salmonids since the 1950s. Today it is still a major concern for many fish farms in Europe and is therefore being watched closely by the European Community Reference Laboratory for Fish Diseases. It was first discovered in the US in 1988 among salmon returning from the Pacific in Washington state. This North American genotype was identified as a distinct, more marine-stable strain than the European genotype. VHS has sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Disease And Parasites
Like humans and other animals, fish suffer from diseases and parasites. Fish defences against disease are specific and non-specific. Non-specific defences include skin and scales, as well as the mucus layer secreted by the epidermis that traps microorganisms and inhibits their growth. If pathogens breach these defences, fish can develop inflammatory responses that increase the flow of blood to infected areas and deliver white blood cells that attempt to destroy the pathogens. Specific defences are specialised responses to particular pathogens recognised by the fish's body, that is adaptative immune responses. In recent years, vaccines have become widely used in aquaculture and ornamental fish, for example vaccines for commercial food fishes like Aeromonas salmonicida, furunculosis in salmon and Lactococcosis\Streptococcosis in farmed grey mullet, Tilapia and koi herpes virus in koi. Some commercially important fish diseases are VHS, ICH, and whirling disease. Parasites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabdoviridae
''Rhabdoviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Vertebrates (including mammals and humans), invertebrates, plants, fungi and protozoans serve as natural hosts. Diseases associated with member viruses include rabies encephalitis caused by the rabies virus, and flu-like symptoms in humans caused by vesiculoviruses. The name is derived from Ancient Greek , meaning rod, referring to the shape of the viral particles. The family has 40 genera, most assigned to three subfamilies. Structure The individual virus particles (virions) of rhabdoviruses are composed of RNA, protein, carbohydrate and lipid. They have complex bacilliform or bullet-like shapes. All these viruses have structural similarities and have been classified as a single family. The virions are about 75 nm wide and 180 nm long. Rhabdoviruses are enveloped and have helical nucleocapsids and their genomes are linear, around 11–15 kb in length. Rhabdoviruses c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Genetics
Reverse genetics is a method in molecular genetics that is used to help understand the function(s) of a gene by analysing the phenotypic effects caused by genetically engineering specific nucleic acid sequences within the gene. The process proceeds in the opposite direction to forward genetic screens of classical genetics. While forward genetics seeks to find the genetic basis of a phenotype or trait, reverse genetics seeks to find what phenotypes are controlled by particular genetic sequences. Automated DNA sequencing generates large volumes of genomic sequence data relatively rapidly. Many genetic sequences are discovered in advance of other, less easily obtained, biological information. Reverse genetics attempts to connect a given genetic sequence with specific effects on the organism. Reverse genetics systems can also allow the recovery and generation of infectious or defective viruses with desired mutations. This allows the ability to study the virus ''in vitro'' and ''in v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus Polymerase
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] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix Protein
Viral matrix proteins are structural proteins linking the viral envelope with the virus core. They play a crucial role in virus assembly, and interact with the RNP complex as well as with the viral membrane. They are found in many enveloped viruses including paramyxoviruses, orthomyxoviruses, herpesviruses, retroviruses, filoviruses and other groups. An example is the M1 protein of the influenza virus, showing affinity to the glycoproteins inserted in the host cell membrane on one side and affinity for the RNP complex molecules on the other side, which allows formation at the membrane of a complex made of the viral ribonucleoprotein at the inner side indirectly connected to the viral glycoproteins protruding from the membrane. This assembly complex will now bud out of the cell as new mature viruses. Viral matrix proteins, like many other viral proteins, can exert different functions during the course of the infection. For example, in rhabdoviruses, binding of M proteins to nucle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoprotein
A phosphoprotein is a protein that is posttranslationally modified by the attachment of either a single phosphate group, or a complex molecule such as 5'-phospho-DNA, through a phosphate group. The target amino acid is most often serine, threonine, or tyrosine residues (mostly in eukaryotes), or aspartic acid or histidine residues (mostly in prokaryotes). Biological function The phosphorylation of proteins is a major regulatory mechanism in cells. Clinical significance Phosphoproteins have been proposed as biomarkers for breast cancer. See also *Protein phosphorylation Protein phosphorylation is a reversible post-translational modification of proteins in which an amino acid residue is phosphorylated by a protein kinase by the addition of a covalently bound phosphate group. Phosphorylation alters the structural ... References Phosphoproteins {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase
A polymerase is an enzyme ( EC 2.7.7.6/7/19/48/49) that synthesizes long chains of polymers or nucleic acids. DNA polymerase and RNA polymerase are used to assemble DNA and RNA molecules, respectively, by copying a DNA template strand using base-pairing interactions or RNA by half ladder replication. A DNA polymerase from the thermophilic bacterium, ''Thermus aquaticus'' (''Taq'') ( PDBbr>1BGX EC 2.7.7.7) is used in the polymerase chain reaction, an important technique of molecular biology. A polymerase may be template dependent or template independent. Poly-A-polymerase is an example of template independent polymerase. Terminal deoxynucleotidyl transferase also known to have template independent and template dependent activities. Types By function *DNA polymerase (DNA-directed DNA polymerase, DdDP) **Family A: DNA polymerase I; Pol γ, θ, ν **Family B: DNA polymerase II; Pol α, δ, ε, ζ **Family C: DNA polymerase III holoenzyme **Family X: Pol β, λ, μ * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleocapsid
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 more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilobase
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (or "Watson–Crick–Franklin") base pairs (guanine–cytosine and adenine–thymine) allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The complementary nature of this based-paired structure provides a redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and RNA polymerase transcribes DNA into RNA. Many DNA-binding proteins ca ... [...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 sequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peplomer
In virology, a spike protein or peplomer protein is a protein that forms a large structure known as a spike or peplomer projecting from the surface of an enveloped virus. as cited in The proteins are usually glycoproteins that form dimers or trimers. History and etymology The term "peplomer" refers to an individual spike from the viral surface; collectively the layer of material at the outer surface of the virion has been referred to as the "peplos". The term is derived from the Greek peplos, "a loose outer garment", "robe or cloak", or "woman smantle". Early systems of viral taxonomy, such as the Lwoff- Horne- Tournier system proposed in the 1960s, used the appearance and morphology of the "peplos" and peplomers as important characteristics for classification. More recently, the term "peplos" is considered a synonym for viral envelope. Properties Spikes or peplomers are usually rod- or club-shaped projections from the viral surface. Spike proteins are membrane proteins w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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