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Luciferase
Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is usually distinguished from a photoprotein. The name was first used by Raphaël Dubois who invented the words '' luciferin'' and ''luciferase'', for the substrate and enzyme, respectively. Both words are derived from the Latin word ''lucifer'', meaning "lightbearer", which in turn is derived from the Latin words for "light" (''lux)'' and "to bring or carry" (''ferre)''.Luciferases are widely used in biotechnology, for bioluminescence imaging microscopy and as reporter genes, for many of the same applications as fluorescent proteins. However, unlike fluorescent proteins, luciferases do not require an external light source, but do require addition of luciferin, the consumable substrate. Examples A variety of organisms regulate their light production using different luciferases in a variety of light-emitting reactions. The majority of studied luciferases have been found in anim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefly Luciferase
Firefly luciferase is the light-emitting enzyme responsible for the bioluminescence of fireflies and click beetles. The enzyme catalyses the oxidation of firefly luciferin, requiring oxygen and ATP. Because of the requirement of ATP, firefly luciferases have been used extensively in biotechnology. Mechanism of reaction The chemical reaction catalyzed by firefly luciferase takes place in two steps: * luciferin + ATP → luciferyl adenylate + PPi * luciferyl adenylate + O2 → oxyluciferin + AMP + light Light is produced because the reaction forms oxyluciferin in an electronically excited state. The reaction releases a photon of light as oxyluciferin goes back to the ground state. Luciferyl adenylate can additionally participate in a side reaction with O2 to form hydrogen peroxide and dehydroluciferyl-AMP. About 20% of the luciferyl adenylate intermediate is oxidized in this pathway. Firefly luciferase generates light from luciferin in a multistep process. First, D-luc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reporter Gene
In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to a regulatory sequence of another gene of interest in bacteria, cell culture, animals or plants. Such genes are called reporters because the characteristics they confer on organisms expressing them are easily identified and measured, or because they are selectable markers. Reporter genes are often used as an indication of whether a certain gene has been taken up by or expressed in the cell or organism population. Common reporter genes To introduce a reporter gene into an organism, scientists place the reporter gene and the gene of interest in the same DNA construct to be inserted into the cell or organism. For bacteria or prokaryotic cells in culture, this is usually in the form of a circular DNA molecule called a plasmid. For viruses, this is known as a viral vector. It is important to use a reporter gene that is not natively expressed in the cell or organism under study, since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioluminescent Bacteria
Bioluminescent bacteria are light-producing bacteria that are predominantly present in sea water, marine sediments, the surface of decomposing fish and in the gut of marine animals. While not as common, bacterial bioluminescence is also found in terrestrial and freshwater bacteria. These bacteria may be free living (such as ''Vibrio harveyi'') or in symbiosis with animals such as the Hawaiian Bobtail squid ('' Aliivibrio fischeri'') or terrestrial nematodes ('' Photorhabdus luminescens''). The host organisms provide these bacteria a safe home and sufficient nutrition. In exchange, the hosts use the light produced by the bacteria for camouflage, prey and/or mate attraction. Bioluminescent bacteria have evolved symbiotic relationships with other organisms in which both participants benefit close to equally. Another possible reason bacteria use luminescence reaction is for quorum sensing, an ability to regulate gene expression in response to bacterial cell density. History Records ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioluminescence
Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus '' Vibrio''; in others, it is autogenic, produced by the animals themselves. In a general sense, the principal chemical reaction in bioluminescence involves a light-emitting molecule and an enzyme, generally called luciferin and luciferase, respectively. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin. In all characterized cases, the enzyme catalyzes the oxidation of the luciferin. In some species, the luciferase requires other cofactors, such as calcium or magnesium ions, and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fireflies
The Lampyridae are a family of elateroid beetles with more than 2,000 described species, many of which are light-emitting. They are soft-bodied beetles commonly called fireflies, lightning bugs, or glowworms for their conspicuous production of light, mainly during twilight, to attract mates. Light production in the Lampyridae is thought to have originated as an honest warning signal that the larvae were distasteful; this was co-opted in evolution as a mating signal in the adults. In a further development, female fireflies of the genus ''Photuris'' mimic the flash pattern of '' Photinus'' species to trap their males as prey. Fireflies are found in temperate and tropical climates. Many live in marshes or in wet, wooded areas where their larvae have abundant sources of food. While all known fireflies glow as larvae, only some species produce light in their adult stage, and the location of the light organ varies among species and between sexes of the same species. Fireflies h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luciferin
Luciferin (from the Latin ''lucifer'', "light-bearer") is a generic term for the light-emitting compound found in organisms that generate bioluminescence. Luciferins typically undergo an enzyme-catalyzed reaction with molecular oxygen. The resulting transformation, which usually involves splitting off a molecular fragment, produces an excited state intermediate that emits light upon decaying to its ground state. The term may refer to molecules that are substrates for both luciferases and photoproteins. Types Luciferins are a class of small-molecule substrates that react with oxygen in the presence of a luciferase (an enzyme) to release energy in the form of light. It is not known just how many types of luciferins there are, but some of the better-studied compounds are listed below. Because of the chemical diversity of luciferins, there is no clear unifying mechanism of action, except that all require molecular oxygen, The variety of luciferins and luciferases, their diver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photinus Pyralis
''Photinus pyralis'', known by the common names common eastern firefly and big dipper firefly, is the most common species of firefly in North America. ''P. pyralis'' is a flying and light-producing beetle with a light organ on the ventral side of its abdomen. This organism is sometimes incorrectly classified as ''Photuris pyralis'', which likely results from mistaking the similar-sounding genus ''Photuris''. The ''Photuris'' female may also lure a ''Photinus pyralis'' to be eaten to obtain spider-repellent steroids called " lucibufagins". In males the light organ covers the entire ventral surface of the three most posterior segments and in females it only covers a portion of the third posterior segment.Mast, S.O. 1912. Behaviour of fire-flies (Photinus pyralis) with special references to the problem of orientation. 256-272 These fireflies are most noticeable around twilight, in the early part of the evening and hover close to the ground. The species' common name refers to the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renilla-luciferin 2-monooxygenase
Renilla-luciferin 2-monooxygenase, Renilla luciferase, or RLuc, is a bioluminescent enzyme found in ''Renilla reniformis'', belonging to a group of coelenterazine luciferases. Of this group of enzymes, the luciferase from ''Renilla reniformis'' has been the most extensively studied, and due to its bioluminescence requiring only molecular oxygen, has a wide range of applications, with uses as a reporter gene probe in cell culture, in vivo imaging, and various other areas of biological research. Recently, chimeras of RLuc have been developed and demonstrated to be the brightest luminescent proteins to date, and have proved effective in both noninvasive single-cell and whole body imaging. Note that the EC record also includes other unrelated enzymes that catalyze the same reaction. An example is the calcium-dependent photoprotein aequorin: while Rluc is in the AB hydrolase superfamily, aequorin is an EF hand protein. The name does not specifically refer to ''Renilla'', but instea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioluminescence Imaging
Bioluminescence imaging (BLI) is a technology developed over the past decade that allows for the noninvasive study of ongoing biological processes. Recently, bioluminescence tomography (BLT) has become possible and several systems have become commercially available. In 2011, PerkinElmer acquired one of the most popular lines of optical imaging systems with bioluminescence from Caliper Life Sciences. Background Bioluminescence is the process of light emission in living organisms. Bioluminescence imaging utilizes native light emission from one of several organisms which bioluminesce. The three main sources are the North American firefly, the sea pansy (and related marine organisms), and bacteria like '' Photorhabdus luminescens'' and ''Vibrio fischeri''. The DNA encoding the luminescent protein is incorporated into the laboratory animal either via a viral vector or by creating a transgenic animal. Rodent models of cancer spread can be studied through bioluminescence imaging.f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elateroidea
The Elateroidea are a large superfamily of beetles. It contains the familiar click beetles, fireflies, and soldier beetles and their relatives. It consists of about 25,000 species. Description Elateroidea is a morphologically diverse group, including hard-bodied beetles with 5 abdominal ventrites, soft-bodied beetles with 7-8 ventrites connected with membranes (formerly known as cantharoids), and beetles with intermediate forms. They have a range of sizes and colours, but in terms of shape, they are usually narrow and parallel-sided as adults. Many of the sclerotised elateroids ( Cerophytidae, Eucnemidae, Throscidae, Elateridae) have a clicking mechanism. This is a peg on the prothorax which fits into a cavity in the mesothorax. When a click beetle bends its body, the peg snaps into the cavity, causing the beetle's body to straighten so suddenly that it jumps into the air. Most beetles capable of bioluminescence are in the Elateroidea, in the families Lampyridae (~2000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogeny
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
