Aequorin is a calcium-activated photoprotein isolated from the hydrozoan Aequorea victoria . Its bioluminescence was studied decades before the protein was isolated from the animal by Osamu Shimomura in 1962. In the animal, the protein occurs together with the green fluorescent protein to produce green light by resonant energy transfer , while aequorin by itself generates blue light.
162-509: Discussions of "jellyfish DNA" that can make "glowing" animals often refer to transgenic animals that express the green fluorescent protein, not aequorin, although both originally derive from the same animal. Apoaequorin, the protein portion of aequorin, is an ingredient in the dietary supplement Prevagen. The US Federal Trade Commission (FTC) has charged the maker with false advertising for its memory improvement claims. Work on aequorin began with E. Newton Harvey in 1921. Though Harvey
324-572: A cascade method, Swiss chemist and physicist Raoul Pierre Pictet evaporated liquid sulfur dioxide in order to liquefy carbon dioxide, which in turn was evaporated to cool oxygen gas enough to liquefy it. He sent a telegram on December 22, 1877, to the French Academy of Sciences in Paris announcing his discovery of liquid oxygen . Just two days later, French physicist Louis Paul Cailletet announced his own method of liquefying molecular oxygen. Only
486-554: A glyphosate or glufosinate based one. Genetically modified crops engineered to resist herbicides are now more available than conventionally bred resistant varieties; in the USA 93% of soybeans and most of the GM maize grown is glyphosate tolerant. Most currently available genes used to engineer insect resistance come from the Bacillus thuringiensis bacterium and code for delta endotoxins . A few use
648-664: A herbicide ). The second generation of crops aimed to improve the quality, often by altering the nutrient profile . Third generation genetically modified crops could be used for non-food purposes, including the production of pharmaceutical agents , biofuels , and other industrially useful goods, as well as for bioremediation . There are three main aims to agricultural advancement; increased production, improved conditions for agricultural workers and sustainability . GM crops contribute by improving harvests through reducing insect pressure, increasing nutrient value and tolerating different abiotic stresses . Despite this potential, as of 2018,
810-597: A knockout mouse ) were created in 1989. The first transgenic livestock were produced in 1985 and the first animal to synthesize transgenic proteins in their milk were mice in 1987. The mice were engineered to produce human tissue plasminogen activator , a protein involved in breaking down blood clots . In 1983, the first genetically engineered plant was developed by Michael W. Bevan , Richard B. Flavell and Mary-Dell Chilton . They infected tobacco with Agrobacterium transformed with an antibiotic resistance gene and through tissue culture techniques were able to grow
972-477: A chemical element. The name oxygen was coined in 1777 by Antoine Lavoisier , who first recognized oxygen as a chemical element and correctly characterized the role it plays in combustion. Common industrial uses of oxygen include production of steel , plastics and textiles , brazing, welding and cutting of steels and other metals , rocket propellant , oxygen therapy , and life support systems in aircraft , submarines , spaceflight and diving . One of
1134-671: A factor of 100. Geographically though the spread has been uneven, with strong growth in the Americas and parts of Asia and little in Europe and Africa. Its socioeconomic spread has been more even, with approximately 54% of worldwide GM crops grown in developing countries in 2013. Although doubts have been raised, most studies have found growing GM crops to be beneficial to farmers through decreased pesticide use as well as increased crop yield and farm profit. The majority of GM crops have been modified to be resistant to selected herbicides, usually
1296-434: A few drops of the liquid were produced in each case and no meaningful analysis could be conducted. Oxygen was liquefied in a stable state for the first time on March 29, 1883, by Polish scientists from Jagiellonian University , Zygmunt Wróblewski and Karol Olszewski . In 1891 Scottish chemist James Dewar was able to produce enough liquid oxygen for study. The first commercially viable process for producing liquid oxygen
1458-468: A food source. Genetic engineering has been proposed as a way to control mosquitos, a vector for many deadly diseases. Although human gene therapy is still relatively new, it has been used to treat genetic disorders such as severe combined immunodeficiency and Leber's congenital amaurosis . Many objections have been raised over the development of GMOs, particularly their commercialization. Many of these involve GM crops and whether food produced from them
1620-522: A gene is isolated it can be stored inside the bacteria, providing an unlimited supply for research. A large number of custom plasmids make manipulating DNA extracted from bacteria relatively easy. Their ease of use has made them great tools for scientists looking to study gene function and evolution . The simplest model organisms come from bacteria, with most of our early understanding of molecular biology coming from studying Escherichia coli . Scientists can easily manipulate and combine genes within
1782-439: A genetically modified organism is a multi-step process. Genetic engineers must isolate the gene they wish to insert into the host organism and combine it with other genetic elements, including a promoter and terminator region and often a selectable marker . A number of techniques are available for inserting the isolated gene into the host genome . Recent advancements using genome editing techniques, notably CRISPR , have made
SECTION 10
#17328770265011944-482: A human protein ( somatostatin ) in E. coli . Genentech announced the production of genetically engineered human insulin in 1978. The insulin produced by bacteria, branded Humulin , was approved for release by the Food and Drug Administration in 1982. In 1988, the first human antibodies were produced in plants. In 1987, a strain of Pseudomonas syringae became the first genetically modified organism to be released into
2106-481: A light sky-blue color caused by absorption in the red (in contrast with the blue color of the sky, which is due to Rayleigh scattering of blue light). High-purity liquid O 2 is usually obtained by the fractional distillation of liquefied air. Liquid oxygen may also be condensed from air using liquid nitrogen as a coolant. Liquid oxygen is a highly reactive substance and must be segregated from combustible materials. The spectroscopy of molecular oxygen
2268-560: A major role in absorbing energy from singlet oxygen and converting it to the unexcited ground state before it can cause harm to tissues. The common allotrope of elemental oxygen on Earth is called dioxygen , O 2 , the major part of the Earth's atmospheric oxygen (see Occurrence ). O 2 has a bond length of 121 pm and a bond energy of 498 kJ/mol . O 2 is used by complex forms of life, such as animals, in cellular respiration . Other aspects of O 2 are covered in
2430-416: A new plant containing the resistance gene. The gene gun was invented in 1987, allowing transformation of plants not susceptible to Agrobacterium infection. In 2000, Vitamin A -enriched golden rice was the first plant developed with increased nutrient value. In 1976, Genentech , the first genetic engineering company was founded by Herbert Boyer and Robert Swanson ; a year later, the company produced
2592-400: A number of exceptions added as the result of pressure from scientific and farming communities, as well as developments in science. The EU definition later excluded traditional breeding, in vitro fertilization, induction of polyploidy , mutation breeding , and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism in the process. Another approach
2754-438: A part of air that he called spiritus nitroaereus . In one experiment, he found that placing either a mouse or a lit candle in a closed container over water caused the water to rise and replace one-fourteenth of the air's volume before extinguishing the subjects. From this, he surmised that nitroaereus is consumed in both respiration and combustion. Mayow observed that antimony increased in weight when heated, and inferred that
2916-404: A process called eutrophication and the decay of these organisms and other biomaterials may reduce the O 2 content in eutrophic water bodies. Scientists assess this aspect of water quality by measuring the water's biochemical oxygen demand , or the amount of O 2 needed to restore it to a normal concentration. Paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in
3078-481: A range of deadly diseases, including malaria , yellow fever and dengue fever . Mosquitos can evolve quickly so it becomes a balancing act of killing them before the Plasmodium they carry becomes the infectious disease, but not so fast that they become resistant to the fungi. By genetically engineering fungi like Metarhizium anisopliae and Beauveria bassiana to delay the development of mosquito infectiousness
3240-535: A relatively broad range of host cells, although they have been known to elicit immune responses in the host and only provide short term expression. Other common vectors are adeno-associated viruses , which have lower toxicity and longer-term expression, but can only carry about 4kb of DNA. Herpes simplex viruses make promising vectors, having a carrying capacity of over 30kb and providing long term expression, although they are less efficient at gene delivery than other vectors. The best vectors for long term integration of
3402-412: A significant degree; instead it degrades into amino acids". Genetically modified organism A genetically modified organism ( GMO ) is any organism whose genetic material has been altered using genetic engineering techniques . The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in
SECTION 20
#17328770265013564-545: A single cell from a mature plant can be harvested and under the right conditions can develop into a new plant. This ability can be taken advantage of by genetic engineers; by selecting for cells that have been successfully transformed in an adult plant a new plant can then be grown that contains the transgene in every cell through a process known as tissue culture . Much of the advances in the field of genetic engineering has come from experimentation with tobacco . Major advances in tissue culture and plant cellular mechanisms for
3726-427: A single cell is transformed with genetic material, the organism must be regenerated from that single cell. In plants this is accomplished through tissue culture . In animals it is necessary to ensure that the inserted DNA is present in the embryonic stem cells . Further testing using PCR , Southern hybridization , and DNA sequencing is conducted to confirm that an organism contains the new gene. Traditionally
3888-458: A small proportion of manganese dioxide. Oxygen levels in the atmosphere are trending slightly downward globally, possibly because of fossil-fuel burning. At standard temperature and pressure , oxygen is a colorless, odorless, and tasteless gas with the molecular formula O 2 , referred to as dioxygen. As dioxygen , two oxygen atoms are chemically bound to each other. The bond can be variously described based on level of theory, but
4050-449: A triplet electronic ground state . An electron configuration with two unpaired electrons, as is found in dioxygen orbitals (see the filled π* orbitals in the diagram) that are of equal energy—i.e., degenerate —is a configuration termed a spin triplet state. Hence, the ground state of the O 2 molecule is referred to as triplet oxygen . The highest-energy, partially filled orbitals are antibonding , and so their filling weakens
4212-489: A useful tool in molecular biology for the measurement of intracellular Ca levels. The early successful purification of aequorin led to the first experiments involving the injection of the protein into the tissues of living animals to visualize the physiological release of calcium in the muscle fibers of a barnacle. Since then, the protein has been widely used in many model biological systems , including zebrafish , rats , mice , and cultured cells . Cultured cells expressing
4374-449: A virus to express spinach defensin proteins. The virus was injected into orange trees to combat citrus greening disease that had reduced orange production by 70% since 2005. Natural viral diseases, such as myxomatosis and rabbit hemorrhagic disease , have been used to help control pest populations. Over time the surviving pests become resistant, leading researchers to look at alternative methods. Genetically modified viruses that make
4536-486: A way that "does not occur naturally by mating and/or natural recombination ". A wide variety of organisms have been genetically modified (GM), including animals, plants, and microorganisms. Genetic modification can include the introduction of new genes or enhancing, altering, or knocking out endogenous genes. In some genetic modifications, genes are transferred within the same species , across species (creating transgenic organisms), and even across kingdoms . Creating
4698-417: A wide range of plants has originated from systems developed in tobacco. It was the first plant to be altered using genetic engineering and is considered a model organism for not only genetic engineering, but a range of other fields. As such the transgenic tools and procedures are well established making tobacco one of the easiest plants to transform. Another major model organism relevant to genetic engineering
4860-439: Is Arabidopsis thaliana . Its small genome and short life cycle makes it easy to manipulate and it contains many homologs to important crop species. It was the first plant sequenced , has a host of online resources available and can be transformed by simply dipping a flower in a transformed Agrobacterium solution. In research, plants are engineered to help discover the functions of certain genes. The simplest way to do this
5022-450: Is "clinically shown" to work. According to the FTC, "the marketers of Prevagen preyed on the fears of older consumers experiencing age-related memory loss ". Quincy said that it would fight the charges. Prior to the suit, a clinical trial run by researchers employed by Quincy Bioscience "found no overall benefit compared to a placebo for its primary endpoints involving memory and cognition", while
Aequorin - Misplaced Pages Continue
5184-570: Is a corrosive byproduct of smog and thus an air pollutant . Oxygen was isolated by Michael Sendivogius before 1604, but it is commonly believed that the element was discovered independently by Carl Wilhelm Scheele , in Uppsala , in 1773 or earlier, and Joseph Priestley in Wiltshire , in 1774. Priority is often given for Priestley because his work was published first. Priestley, however, called oxygen "dephlogisticated air", and did not recognize it as
5346-483: Is a leading issue with critics. Gene flow , impact on non-target organisms, and escape are the major environmental concerns. Countries have adopted regulatory measures to deal with these concerns. There are differences in the regulation for the release of GMOs between countries, with some of the most marked differences occurring between the US and Europe. Key issues concerning regulators include whether GM food should be labeled and
5508-477: Is absorbed by specialized respiratory organs called gills , through the skin or via the gut ; in terrestrial animals such as tetrapods , oxygen in air is actively taken into the body via specialized organs known as lungs , where gas exchange takes place to diffuse oxygen into the blood and carbon dioxide out, and the body's circulatory system then transports the oxygen to other tissues where cellular respiration takes place. However in insects ,
5670-508: Is associated with the atmospheric processes of aurora and airglow . The absorption in the Herzberg continuum and Schumann–Runge bands in the ultraviolet produces atomic oxygen that is important in the chemistry of the middle atmosphere. Excited-state singlet molecular oxygen is responsible for red chemiluminescence in solution. Table of thermal and physical properties of oxygen (O 2 ) at atmospheric pressure: Naturally occurring oxygen
5832-426: Is associated with various "Non-GMO" or "GMO-free" labeling schemes in food marketing, where even products such as water or salt, which do not contain any organic substances and genetic material (and thus cannot be genetically modified by definition), are being labeled to create an impression of being "more healthy". Creating a genetically modified organism (GMO) is a multi-step process. Genetic engineers must isolate
5994-505: Is called transduction and if successful the recipient of the introduced DNA becomes a GMO. Different viruses have different efficiencies and capabilities. Researchers can use this to control for various factors; including the target location, insert size, and duration of gene expression. Any dangerous sequences inherent in the virus must be removed, while those that allow the gene to be delivered effectively are retained. While viral vectors can be used to insert DNA into almost any organism it
6156-469: Is composed of three stable isotopes , O , O , and O , with O being the most abundant (99.762% natural abundance ). Most O is synthesized at the end of the helium fusion process in massive stars but some is made in the neon burning process . O is primarily made by the burning of hydrogen into helium during the CNO cycle , making it a common isotope in the hydrogen burning zones of stars. Most O
6318-404: Is especially relevant for its potential in treating human disease. Although primarily still at trial stages, there has been some successes using gene therapy to replace defective genes. This is most evident in curing patients with severe combined immunodeficiency rising from adenosine deaminase deficiency (ADA-SCID), although the development of leukemia in some ADA-SCID patients along with
6480-516: Is interest in developing an extracellular expression system within the bacteria to reduce costs and make the production of more products economical. With a greater understanding of the role that the microbiome plays in human health, there is a potential to treat diseases by genetically altering the bacteria to, themselves, be therapeutic agents. Ideas include altering gut bacteria so they destroy harmful bacteria, or using bacteria to replace or increase deficient enzymes or proteins. One research focus
6642-447: Is oxygen as a component of water, the major constituent of lifeforms. Oxygen in Earth's atmosphere is produced by biotic photosynthesis , in which photon energy in sunlight is captured by chlorophyll to split water molecules and then react with carbon dioxide to produce carbohydrates and oxygen is released as a byproduct . Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by
Aequorin - Misplaced Pages Continue
6804-402: Is possible to engineer bacteriophages to express modified proteins on their surface and join them up in specific patterns (a technique called phage display ). These structures have potential uses for energy storage and generation, biosensing and tissue regeneration with some new materials currently produced including quantum dots , liquid crystals , nanorings and nanofibres . The battery
6966-441: Is produced when N (made abundant from CNO burning) captures a He nucleus, making O common in the helium-rich zones of evolved, massive stars . Fifteen radioisotopes have been characterized, ranging from O to O. The most stable are O with a half-life of 122.24 seconds and O with a half-life of 70.606 seconds. All of the remaining radioactive isotopes have half-lives that are less than 27 seconds and
7128-408: Is reasonably and simply described as a covalent double bond that results from the filling of molecular orbitals formed from the atomic orbitals of the individual oxygen atoms, the filling of which results in a bond order of two. More specifically, the double bond is the result of sequential, low-to-high energy, or Aufbau , filling of orbitals, and the resulting cancellation of contributions from
7290-456: Is safe and what impact growing them will have on the environment. Other concerns are the objectivity and rigor of regulatory authorities, contamination of non-genetically modified food, control of the food supply , patenting of life , and the use of intellectual property rights. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety
7452-490: Is some confusion as to whether they are GMOs. The EU has adjudged that they are changing their GMO definition to include "organisms obtained by mutagenesis ", but has excluded them from regulation based on their "long safety record" and that they have been "conventionally been used in a number of applications". In contrast the USDA has ruled that gene edited organisms are not considered GMOs. Even greater inconsistency and confusion
7614-712: Is temperature-dependent, and about twice as much ( 14.6 mg/L ) dissolves at 0 °C than at 20 °C ( 7.6 mg/L ). At 25 °C and 1 standard atmosphere (101.3 kPa ) of air, freshwater can dissolve about 6.04 milliliters (mL) of oxygen per liter , and seawater contains about 4.95 mL per liter. At 5 °C the solubility increases to 9.0 mL (50% more than at 25 °C) per liter for freshwater and 7.2 mL (45% more) per liter for sea water. Oxygen condenses at 90.20 K (−182.95 °C, −297.31 °F) and freezes at 54.36 K (−218.79 °C, −361.82 °F). Both liquid and solid O 2 are clear substances with
7776-435: Is the result of the oxygen cycle . This biogeochemical cycle describes the movement of oxygen within and between its three main reservoirs on Earth: the atmosphere, the biosphere, and the lithosphere . The main driving factor of the oxygen cycle is photosynthesis , which is responsible for modern Earth's atmosphere. Photosynthesis releases oxygen into the atmosphere, while respiration , decay , and combustion remove it from
7938-404: Is the substrate whose oxidation the enzyme catalyzes. When coelenterazine is bound, it is called aequorin. Notably, the protein contains three EF hand motifs that function as binding sites for Ca ions. The protein is a member of the superfamily of the calcium-binding proteins, of which there are some 66 subfamilies. The crystal structure revealed that aequorin binds coelenterazine and oxygen in
8100-514: Is to alter them so they can directly treat diseases. This can be through expression of protective proteins or by directly targeting infected cells. In 2004, researchers reported that a genetically modified virus that exploits the selfish behavior of cancer cells might offer an alternative way of killing tumours. Since then, several researchers have developed genetically modified oncolytic viruses that show promise as treatments for various types of cancer . In 2017, researchers genetically modified
8262-453: Is to modify Lactobacillus , bacteria that naturally provide some protection against HIV , with genes that will further enhance this protection. If the bacteria do not form colonies inside the patient, the person must repeatedly ingest the modified bacteria in order to get the required doses. Enabling the bacteria to form a colony could provide a more long-term solution, but could also raise safety concerns as interactions between bacteria and
SECTION 50
#17328770265018424-412: Is to remove the gene and see what phenotype develops compared to the wild type form. Any differences are possibly the result of the missing gene. Unlike mutagenisis , genetic engineering allows targeted removal without disrupting other genes in the organism. Some genes are only expressed in certain tissues, so reporter genes, like GUS , can be attached to the gene of interest allowing visualization of
8586-721: Is to use vectors to create novel vaccines for diseases that have no vaccines available or the vaccines that do not work effectively, such as AIDS , malaria , and tuberculosis . The most effective vaccine against Tuberculosis, the Bacillus Calmette–Guérin (BCG) vaccine , only provides partial protection. A modified vaccine expressing a M tuberculosis antigen is able to enhance BCG protection. It has been shown to be safe to use at phase II trials , although not as effective as initially hoped. Other vector-based vaccines have already been approved and many more are being developed. Another potential use of genetically modified viruses
8748-408: Is unclear if the cDNA variants can account for all of the isoforms of the protein. Early studies of the bioluminescence of Aequorea by E. Newton Harvey had noted that the bioluminescence appears as a ring around the bell, and occurs even in the absence of air. This was remarkable because most bioluminescence reactions require oxygen , and led to the idea that the animals somehow store oxygen. It
8910-457: Is unusual among the planets of the Solar System in having such a high concentration of oxygen gas in its atmosphere: Mars (with 0.1% O 2 by volume) and Venus have much less. The O 2 surrounding those planets is produced solely by the action of ultraviolet radiation on oxygen-containing molecules such as carbon dioxide. The unusually high concentration of oxygen gas on Earth
9072-517: Is usually given priority in the discovery. The French chemist Antoine Laurent Lavoisier later claimed to have discovered the new substance independently. Priestley visited Lavoisier in October 1774 and told him about his experiment and how he liberated the new gas. Scheele had also dispatched a letter to Lavoisier on September 30, 1774, which described his discovery of the previously unknown substance, but Lavoisier never acknowledged receiving it (a copy of
9234-527: Is where the majority of research into genetically engineering food-producing bacteria has gone. The bacteria can be modified to operate more efficiently, reduce toxic byproduct production, increase output, create improved compounds, and remove unnecessary pathways . Food products from genetically modified bacteria include alpha-amylase , which converts starch to simple sugars, chymosin , which clots milk protein for cheese making, and pectinesterase , which improves fruit juice clarity. The majority are produced in
9396-555: The Encyclopedia Britannica defined genetic engineering as "any of a wide range of techniques ... among them artificial insemination , in vitro fertilization ( e.g. , 'test-tube' babies), sperm banks , cloning , and gene manipulation." The European Union (EU) included a similarly broad definition in early reviews, specifically mentioning GMOs being produced by " selective breeding and other means of artificial selection" These definitions were promptly adjusted with
9558-655: The Earth , the Moon , Mars , and meteorites , but were long unable to obtain reference values for the isotope ratios in the Sun , believed to be the same as those of the primordial solar nebula . Analysis of a silicon wafer exposed to the solar wind in space and returned by the crashed Genesis spacecraft has shown that the Sun has a higher proportion of oxygen-16 than does the Earth. The measurement implies that an unknown process depleted oxygen-16 from
9720-463: The Earth's crust in the form of various oxides such as water , carbon dioxide , iron oxides and silicates . All eukaryotic organisms , including plants , animals , fungi , algae and most protists , need oxygen for cellular respiration , which extracts chemical energy by the reaction of oxygen with organic molecules derived from food and releases carbon dioxide as a waste product. In aquatic animals , dissolved oxygen in water
9882-556: The Greek roots ὀξύς (oxys) ( acid , literally 'sharp', from the taste of acids) and -γενής (-genēs) (producer, literally begetter), because he mistakenly believed that oxygen was a constituent of all acids. Chemists (such as Sir Humphry Davy in 1812) eventually determined that Lavoisier was wrong in this regard, but by then the name was too well established. Oxygen entered the English language despite opposition by English scientists and
SECTION 60
#173287702650110044-658: The Iberian peninsula and to help regulate them in Australia. To protect the Iberian species from viral diseases, the myxoma virus was genetically modified to immunize the rabbits, while in Australia the same myxoma virus was genetically modified to lower fertility in the Australian rabbit population. Outside of biology scientists have used a genetically modified virus to construct a lithium-ion battery and other nanostructured materials. It
10206-501: The J. Craig Venter Institute announced that they had created the first synthetic bacterial genome . They named it Synthia and it was the world's first synthetic life form. The first genetically modified animal to be commercialized was the GloFish , a Zebra fish with a fluorescent gene added that allows it to glow in the dark under ultraviolet light . It was released to the US market in 2003. In 2015, AquAdvantage salmon became
10368-457: The Nobel Prize in 2008 for their work on green fluorescent proteins . Aequorin is a holoprotein composed of two distinct units, the apoprotein that is called apoaequorin , which has an approximate molecular weight of 21 kDa , and the prosthetic group coelenterazine , the luciferin. This is to say, apoaequorin is the enzyme produced in the photocytes of the animal, and coelenterazine
10530-482: The calmodulin -based sensor cameleon , developed by Roger Tsien and the troponin -based sensor, TN-XXL , developed by Oliver Griesbeck. Apoaequorin is an ingredient in "Prevagen", which is marketed by Quincy Bioscience as a memory supplement. In 2017, the US Federal Trade Commission (FTC) charged the maker with falsely advertising that the product improves memory, provides cognitive benefits, and
10692-609: The emerald ash borer in North American and the fungal disease, Ceratocystis platani , in European plane trees . The papaya ringspot virus devastated papaya trees in Hawaii in the twentieth century until transgenic papaya plants were given pathogen-derived resistance. However, genetic modification for conservation in plants remains mainly speculative. A unique concern is that a transgenic species may no longer bear enough resemblance to
10854-485: The lambda virus . Herbert Boyer and Stanley Cohen made the first genetically modified organism in 1973. They took a gene from a bacterium that provided resistance to the antibiotic kanamycin , inserted it into a plasmid and then induced other bacteria to incorporate the plasmid. The bacteria that had successfully incorporated the plasmid was then able to survive in the presence of kanamycin. Boyer and Cohen expressed other genes in bacteria. This included genes from
11016-492: The plasma membrane of higher eukaryotes, making aequorin suitable as a Ca reporter in plants, fungi, and mammalian cells. Aequorin has a number of advantages over other Ca indicators. Because the protein is large, it has a low leakage rate from cells compared to lipophilic dyes such as DiI . It lacks phenomena of intracellular compartmentalization or sequestration as is often seen for Voltage-sensitive dyes , and does not disrupt cell functions or embryo development. Moreover,
11178-496: The selection pressure to evolve resistance is reduced. Another strategy is to add proteins to the fungi that block transmission of malaria or remove the Plasmodium altogether. Agaricus bisporus the common white button mushroom, has been gene edited to resist browning, giving it a longer shelf life . The process used CRISPR to knock out a gene that encodes polyphenol oxidase . As it didn't introduce any foreign DNA into
11340-470: The shells and skeletons of marine organisms to determine the climate millions of years ago (see oxygen isotope ratio cycle ). Seawater molecules that contain the lighter isotope , oxygen-16, evaporate at a slightly faster rate than water molecules containing the 12% heavier oxygen-18, and this disparity increases at lower temperatures. During periods of lower global temperatures, snow and rain from that evaporated water tends to be higher in oxygen-16, and
11502-430: The thermal decomposition of potassium nitrate . In Bugaj's view, the isolation of oxygen and the proper association of the substance to that part of air which is required for life, provides sufficient evidence for the discovery of oxygen by Sendivogius. This discovery of Sendivogius was however frequently denied by the generations of scientists and chemists which succeeded him. It is also commonly claimed that oxygen
11664-553: The 17th and the 18th century but none of them recognized it as a chemical element . This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory , which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher , and modified by the chemist Georg Ernst Stahl by 1731, phlogiston theory stated that all combustible materials were made of two parts. One part, called phlogiston,
11826-605: The 1980s artist Jon Davis and geneticist Dana Boyd converted the Germanic symbol for femininity (ᛉ) into binary code and then into a DNA sequence, which was then expressed in Escherichia coli . This was taken a step further in 2012, when a whole book was encoded onto DNA. Paintings have also been produced using bacteria transformed with fluorescent proteins. Viruses are often modified so they can be used as vectors for inserting genetic information into other organisms. This process
11988-531: The 2s electrons, after sequential filling of the low σ and σ orbitals; σ overlap of the two atomic 2p orbitals that lie along the O–O molecular axis and π overlap of two pairs of atomic 2p orbitals perpendicular to the O–O molecular axis, and then cancellation of contributions from the remaining two 2p electrons after their partial filling of the π orbitals. This combination of cancellations and σ and π overlaps results in dioxygen's double-bond character and reactivity, and
12150-527: The American scientist Robert H. Goddard became the first person to develop a rocket engine that burned liquid fuel; the engine used gasoline for fuel and liquid oxygen as the oxidizer . Goddard successfully flew a small liquid-fueled rocket 56 m at 97 km/h on March 16, 1926, in Auburn, Massachusetts , US. In academic laboratories, oxygen can be prepared by heating together potassium chlorate mixed with
12312-542: The Cas9-guideRNA system (adapted from CRISPR). TALEN and CRISPR are the two most commonly used and each has its own advantages. TALENs have greater target specificity, while CRISPR is easier to design and more efficient. Humans have domesticated plants and animals since around 12,000 BCE, using selective breeding or artificial selection (as contrasted with natural selection ). The process of selective breeding , in which organisms with desired traits (and thus with
12474-506: The European Union approved tobacco engineered to be resistant to the herbicide bromoxynil , making it the first genetically engineered crop commercialized in Europe. An insect resistant Potato was approved for release in the US in 1995, and by 1996 approval had been granted to commercially grow 8 transgenic crops and one flower crop (carnation) in 6 countries plus the EU. In 2010, scientists at
12636-478: The Philosopher's Stone drawn from the source of nature and manual experience"] (1604) described a substance contained in air, referring to it as 'cibus vitae' (food of life, ) and according to Polish historian Roman Bugaj, this substance is identical with oxygen. Sendivogius, during his experiments performed between 1598 and 1604, properly recognized that the substance is equivalent to the gaseous byproduct released by
12798-458: The Quincy-sponsored study (known as "Madison Memory Study") was negative, but that the company utilized p-hacking to find favorable results. She wrote that their cited safety studies were all rat studies and their claim that apoaequorin crosses the blood–brain barrier was based solely on a dog study. The American Pharmacists Association warns that Apoaequorin "is unlikely to be absorbed to
12960-438: The Sun's disk of protoplanetary material prior to the coalescence of dust grains that formed the Earth. Oxygen presents two spectrophotometric absorption bands peaking at the wavelengths 687 and 760 nm . Some remote sensing scientists have proposed using the measurement of the radiance coming from vegetation canopies in those bands to characterize plant health status from a satellite platform. This approach exploits
13122-838: The US and even though regulations are in place to allow production in Europe, as of 2015 no food products derived from bacteria are currently available there. Genetically modified bacteria are used to produce large amounts of proteins for industrial use. The bacteria are generally grown to a large volume before the gene encoding the protein is activated. The bacteria are then harvested and the desired protein purified from them. The high cost of extraction and purification has meant that only high value products have been produced at an industrial scale. The majority of these products are human proteins for use in medicine. Many of these proteins are impossible or difficult to obtain via natural methods and they are less likely to be contaminated with pathogens, making them safer. The first medicinal use of GM bacteria
13284-433: The advantage of infecting the insects by contact alone, although they are out competed in efficiency by chemical pesticides . Genetic engineering can improve virulence, usually by adding more virulent proteins, increasing infection rate or enhancing spore persistence. Many of the disease carrying vectors are susceptible to entomopathogenic fungi . An attractive target for biological control are mosquitos , vectors for
13446-434: The aequorin gene can effectively synthesize apoaequorin; however, recombinant expression yields only the apoprotein . Therefore it is necessary to add coelenterazine into the culture medium of the cells to obtain a functional protein and thus use its blue light emission to measure Ca concentration. Coelenterazine is a hydrophobic molecule, and therefore is easily taken up across plant and fungal cell walls , as well as
13608-493: The atmosphere. In the present equilibrium, production and consumption occur at the same rate. Free oxygen also occurs in solution in the world's water bodies. The increased solubility of O 2 at lower temperatures (see Physical properties ) has important implications for ocean life, as polar oceans support a much higher density of life due to their higher oxygen content. Water polluted with plant nutrients such as nitrates or phosphates may stimulate growth of algae by
13770-423: The bacteria to create novel or disrupted proteins and observe the effect this has on various molecular systems. Researchers have combined the genes from bacteria and archaea , leading to insights on how these two diverged in the past. In the field of synthetic biology , they have been used to test various synthetic approaches, from synthesizing genomes to creating novel nucleotides . Bacteria have been used in
13932-412: The bond order from three to two. Because of its unpaired electrons, triplet oxygen reacts only slowly with most organic molecules, which have paired electron spins; this prevents spontaneous combustion. In the triplet form, O 2 molecules are paramagnetic . That is, they impart magnetic character to oxygen when it is in the presence of a magnetic field, because of the spin magnetic moments of
14094-555: The class of consumers who purchased Prevagen over the previous four years. The trial in the case was set for October 2020. As of September 21, 2020, Quincy Bioscience agreed to settle the claims that it misrepresented its Prevagen products as supporting brain health and helping with memory loss. Under the terms of the settlement, eligible purchasers applying by October 26, 2020, for purchases made from 2007 through July 31, 2020, could recover refunds of up to $ 70. Dr. Harriet Hall , writing for Science-Based Medicine , noted that
14256-411: The commercialized crops are limited mostly to cash crops like cotton, soybean, maize and canola and the vast majority of the introduced traits provide either herbicide tolerance or insect resistance. Soybeans accounted for half of all genetically modified crops planted in 2014. Adoption by farmers has been rapid, between 1996 and 2013, the total surface area of land cultivated with GM crops increased by
14418-511: The company's advertising misleadingly cited a few contested subgroup analyses that showed slight improvements. The suit ( Spath, et al. v. Quincy Bioscience Holding Company, Inc., et al. , Case No. 18-cv-12416, D. NJ.) was dismissed in the District court, but an appeal seeking to overturn the dismissal was filed. The suit was consolidated with another against Quincy Pharmaceuticals, Vanderwerff v. Quincy Bioscience (Case No. 17-cv-784, D. NJ), which
14580-546: The confusion on what "occurs naturally", which led to further adjustments and exceptions. There are examples of crops that fit this definition, but are not normally considered GMOs. For example, the grain crop triticale was fully developed in a laboratory in 1930 using various techniques to alter its genome. Genetically engineered organism (GEO) can be considered a more precise term compared to GMO when describing organisms' genomes that have been directly manipulated with biotechnology. The Cartagena Protocol on Biosafety used
14742-674: The death of Jesse Gelsinger in a 1999 trial set back the development of this approach for many years. In 2009, another breakthrough was achieved when an eight-year-old boy with Leber's congenital amaurosis regained normal eyesight and in 2016 GlaxoSmithKline gained approval to commercialize a gene therapy treatment for ADA-SCID. As of 2018, there are a substantial number of clinical trials underway, including treatments for hemophilia , glioblastoma , chronic granulomatous disease , cystic fibrosis and various cancers . The most common virus used for gene delivery comes from adenoviruses as they can carry up to 7.5 kb of foreign DNA and infect
14904-446: The desired genes ) are used to breed the next generation and organisms lacking the trait are not bred, is a precursor to the modern concept of genetic modification. Various advancements in genetics allowed humans to directly alter the DNA and therefore genes of organisms. In 1972, Paul Berg created the first recombinant DNA molecule when he combined DNA from a monkey virus with that of
15066-444: The diatomic elemental molecules in those gases. The first commercial method of producing oxygen was chemical, the so-called Brin process involving a reversible reaction of barium oxide . It was invented in 1852 and commercialized in 1884, but was displaced by newer methods in early 20th century. By the late 19th century scientists realized that air could be liquefied and its components isolated by compressing and cooling it. Using
15228-466: The electron spins are paired. It is much more reactive with common organic molecules than is normal (triplet) molecular oxygen. In nature, singlet oxygen is commonly formed from water during photosynthesis, using the energy of sunlight. It is also produced in the troposphere by the photolysis of ozone by light of short wavelength and by the immune system as a source of active oxygen. Carotenoids in photosynthetic organisms (and possibly animals) play
15390-553: The entire 211 people who completed the study there was no statistically significant difference". The court vigorously dismissed allegations by the company lawyers that the FTC pursued its action for political reasons. On March 23, 2020, a federal magistrate judge in the United States District Court for the Southern District of Florida entered a report and recommendations certifying a nationwide class action for
15552-548: The environment when a strawberry and potato field in California were sprayed with it. The first genetically modified crop , an antibiotic-resistant tobacco plant, was produced in 1982. China was the first country to commercialize transgenic plants, introducing a virus-resistant tobacco in 1992. In 1994, Calgene attained approval to commercially release the Flavr Savr tomato, the first genetically modified food . Also in 1994,
15714-428: The enzymatic reaction. Other studies have shown the presence of an internal cysteine bond that maintains the structure of aequorin. This has also explained the need for a thiol reagent like beta mercaptoethanol in the regeneration of the protein since such reagents weaken the sulfhydryl bonds between cysteine residues, expediting the regeneration of the aequorin. Chemical characterization of aequorin indicates
15876-563: The fact that the Englishman Priestley had first isolated the gas and written about it. This is partly due to a poem praising the gas titled "Oxygen" in the popular book The Botanic Garden (1791) by Erasmus Darwin , grandfather of Charles Darwin . John Dalton 's original atomic hypothesis presumed that all elements were monatomic and that the atoms in compounds would normally have the simplest atomic ratios with respect to one another. For example, Dalton assumed that water's formula
16038-518: The fermentation of wine have been commercialized in the United States and Canada. One has increased malolactic fermentation efficiency, while the other prevents the production of dangerous ethyl carbamate compounds during fermentation. There have also been advances in the production of biofuel from genetically modified fungi. Fungi, being the most common pathogens of insects, make attractive biopesticides . Unlike bacteria and viruses they have
16200-453: The first genetically modified animal to be approved for food use. Approval is for fish raised in Panama and sold in the US. The salmon were transformed with a growth hormone -regulating gene from a Pacific Chinook salmon and a promoter from an ocean pout enabling it to grow year-round instead of only during spring and summer. Bacteria were the first organisms to be genetically modified in
16362-399: The first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium . In his work Pneumatica , Philo observed that inverting a vessel over a burning candle and surrounding the vessel's neck with water resulted in some water rising into the neck. Philo incorrectly surmised that parts of the air in
16524-445: The form of a peroxide , coelenterazine-2-hydroperoxide. The binding site for the first two calcium atoms show a 20 times greater affinity for calcium than the third site. However, earlier claims that only two EF-hands bind calcium were questioned when later structures indicated that all three sites can indeed bind calcium. Thus, titration studies show that all three calcium-binding sites are active but only two ions are needed to trigger
16686-713: The gene into the host genome are retroviruses , but their propensity for random integration is problematic. Lentiviruses are a part of the same family as retroviruses with the advantage of infecting both dividing and non-dividing cells, whereas retroviruses only target dividing cells. Other viruses that have been used as vectors include alphaviruses , flaviviruses , measles viruses , rhabdoviruses , Newcastle disease virus , poxviruses , and picornaviruses . Most vaccines consist of viruses that have been attenuated , disabled, weakened or killed in some way so that their virulent properties are no longer effective. Genetic engineering could theoretically be used to create viruses with
16848-435: The gene they wish to insert into the host organism. This gene can be taken from a cell or artificially synthesized . If the chosen gene or the donor organism's genome has been well studied it may already be accessible from a genetic library . The gene is then combined with other genetic elements, including a promoter and terminator region and a selectable marker . A number of techniques are available for inserting
17010-489: The genes that encode for vegetative insecticidal proteins . The only gene commercially used to provide insect protection that does not originate from B. thuringiensis is the Cowpea trypsin inhibitor (CpTI). CpTI was first approved for use cotton in 1999 and is currently undergoing trials in rice. Less than one percent of GM crops contained other traits, which include providing virus resistance, delaying senescence and altering
17172-410: The ground state, blue light ( wavelength of 465 nm) is emitted. Before coelenteramide is exchanged out, the entire protein is still fluorescent blue. because of the connection between bioluminescence and fluorescence , this property was ultimately important in the discovery of the luciferin coelenterazine . Since the emitted light can be easily detected with a luminometer , aequorin has become
17334-808: The human body are less well understood than with traditional drugs. There are concerns that horizontal gene transfer to other bacteria could have unknown effects. As of 2018 there are clinical trials underway testing the efficacy and safety of these treatments. For over a century, bacteria have been used in agriculture. Crops have been inoculated with Rhizobia (and more recently Azospirillum ) to increase their production or to allow them to be grown outside their original habitat . Application of Bacillus thuringiensis (Bt) and other bacteria can help protect crops from insect infestation and plant diseases. With advances in genetic engineering, these bacteria have been manipulated for increased efficiency and expanded host range. Markers have also been added to aid in tracing
17496-399: The idea; instead, it was based on observations of what happens when something burns, that most common objects appear to become lighter and seem to lose something in the process. Polish alchemist , philosopher , and physician Michael Sendivogius (Michał Sędziwój) in his work De Lapide Philosophorum Tractatus duodecim e naturae fonte et manuali experientia depromti ["Twelve Treatises on
17658-473: The isolated gene into the host genome . Bacteria can be induced to take up foreign DNA, usually by exposed heat shock or electroporation . DNA is generally inserted into animal cells using microinjection , where it can be injected through the cell's nuclear envelope directly into the nucleus , or through the use of viral vectors . In plants the DNA is often inserted using Agrobacterium -mediated recombination , biolistics or electroporation. As only
17820-413: The laboratory, due to the relative ease of modifying their chromosomes. This ease made them important tools for the creation of other GMOs. Genes and other genetic information from a wide range of organisms can be added to a plasmid and inserted into bacteria for storage and modification. Bacteria are cheap, easy to grow, clonal , multiply quickly and can be stored at −80 °C almost indefinitely. Once
17982-499: The letter was found in Scheele's belongings after his death). Lavoisier conducted the first adequate quantitative experiments on oxidation and gave the first correct explanation of how combustion works. He used these and similar experiments, all started in 1774, to discredit the phlogiston theory and to prove that the substance discovered by Priestley and Scheele was a chemical element . In one experiment, Lavoisier observed that there
18144-422: The light emitted by the oxidation of coelenterazine does not depend on any optical excitation, so problems with auto-fluorescence are eliminated. The primary limitation of aequorin is that the prosthetic group coelenterazine is irreversibly consumed to produce light, and requires continuous addition of coelenterazine into the media. Such issues led to developments of other genetically encoded calcium sensors including
18306-620: The location. Other ways to test a gene is to alter it slightly and then return it to the plant and see if it still has the same effect on phenotype. Other strategies include attaching the gene to a strong promoter and see what happens when it is overexpressed, forcing a gene to be expressed in a different location or at different developmental stages . Some genetically modified plants are purely ornamental . They are modified for flower color, fragrance, flower shape and plant architecture. The first genetically modified ornamentals commercialized altered color. Carnations were released in 1997, with
18468-428: The majority of these have half-lives that are less than 83 milliseconds. The most common decay mode of the isotopes lighter than O is β decay to yield nitrogen, and the most common mode for the isotopes heavier than O is beta decay to yield fluorine . Oxygen is the most abundant chemical element by mass in the Earth's biosphere , air, sea and land. Oxygen is the third most abundant chemical element in
18630-503: The most controversial GMOs, in spite of having the most human health and environmental benefits. Animals are generally much harder to transform and the vast majority are still at the research stage. Mammals are the best model organisms for humans. Livestock is modified with the intention of improving economically important traits such as growth rate, quality of meat, milk composition, disease resistance, and survival. Genetically modified fish are used for scientific research, as pets, and as
18792-650: The most popular genetically modified organism, a blue rose (actually lavender or mauve ) created in 2004. The roses are sold in Japan, the United States, and Canada. Other genetically modified ornamentals include Chrysanthemum and Petunia . As well as increasing aesthetic value there are plans to develop ornamentals that use less water or are resistant to the cold, which would allow them to be grown outside their natural environments. It has been proposed to genetically modify some plant species threatened by extinction to be resistant to invasive plants and diseases, such as
18954-418: The most successful and biodiverse terrestrial clade , oxygen is directly conducted to the internal tissues via a deep network of airways . Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins , nucleic acids , carbohydrates and fats , as do the major constituent inorganic compounds of animal shells, teeth, and bone. Most of the mass of living organisms
19116-542: The new genetic material was inserted randomly within the host genome. Gene targeting techniques, which creates double-stranded breaks and takes advantage on the cells natural homologous recombination repair systems, have been developed to target insertion to exact locations . Genome editing uses artificially engineered nucleases that create breaks at specific points. There are four families of engineered nucleases: meganucleases , zinc finger nucleases , transcription activator-like effector nucleases (TALENs), and
19278-494: The nitroaereus must have combined with it. He also thought that the lungs separate nitroaereus from air and pass it into the blood and that animal heat and muscle movement result from the reaction of nitroaereus with certain substances in the body. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract "De respiratione". Robert Hooke , Ole Borch , Mikhail Lomonosov , and Pierre Bayen all produced oxygen in experiments in
19440-430: The non-modified bacteria and confer some frost resistance. Other uses for genetically modified bacteria include bioremediation , where the bacteria are used to convert pollutants into a less toxic form. Genetic engineering can increase the levels of the enzymes used to degrade a toxin or to make the bacteria more stable under environmental conditions. Bioart has also been created using genetically modified bacteria. In
19602-483: The organism it was not deemed to be regulated under existing GMO frameworks and as such is the first CRISPR-edited organism to be approved for release. This has intensified debates as to whether gene-edited organisms should be considered genetically modified organisms and how they should be regulated. Plants have been engineered for scientific research, to display new flower colors, deliver vaccines, and to create enhanced crops. Many plants are pluripotent , meaning that
19764-530: The original species to truly claim that the original species is being conserved. Instead, the transgenic species may be genetically different enough to be considered a new species, thus diminishing the conservation worth of genetic modification. Genetically modified crops are genetically modified plants that are used in agriculture . The first crops developed were used for animal or human food and provide resistance to certain pests, diseases, environmental conditions, spoilage or chemical treatments (e.g. resistance to
19926-451: The photosynthetic activities of autotrophs such as cyanobacteria , chloroplast -bearing algae and plants. A much rarer triatomic allotrope of oxygen , ozone ( O 3 ), strongly absorbs the UVB and UVC wavelengths and forms a protective ozone layer at the lower stratosphere , which shields the biosphere from ionizing ultraviolet radiation . However, ozone present at the surface
20088-400: The plants composition. Oxygen Oxygen is a chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table , a highly reactive nonmetal , and a potent oxidizing agent that readily forms oxides with most elements as well as with other compounds . Oxygen is the most abundant element in Earth's crust , and
20250-527: The process more than the product, which means there could be GMOS and non-GMOs with very similar genotypes and phenotypes. This has led scientists to label it as a scientifically meaningless category, saying that it is impossible to group all the different types of GMOs under one common definition. It has also caused issues for organic institutions and groups looking to ban GMOs. It also poses problems as new processes are developed. The current definitions came in before genome editing became popular and there
20412-473: The production of GMOs much simpler. Herbert Boyer and Stanley Cohen made the first genetically modified organism in 1973, a bacterium resistant to the antibiotic kanamycin . The first genetically modified animal , a mouse, was created in 1974 by Rudolf Jaenisch , and the first plant was produced in 1983. In 1994, the Flavr Savr tomato was released, the first commercialized genetically modified food . The first genetically modified animal to be commercialized
20574-418: The production of food for a long time, and specific strains have been developed and selected for that work on an industrial scale. They can be used to produce enzymes , amino acids , flavorings , and other compounds used in food production. With the advent of genetic engineering, new genetic changes can easily be introduced into these bacteria. Most food-producing bacteria are lactic acid bacteria , and this
20736-418: The protein is somewhat resilient to harsh treatments. Aequorin is heat resistant. Held at 95 °C for 2 minutes the protein lost only 25% activity. Denaturants such as 6-M urea or 4-M guanidine hydrochloride did not destroy the protein. Aequorin is presumably encoded in the genome of Aequorea. At least four copies of the gene were recovered as cDNA from the animal. Because the genome has not been sequenced, it
20898-455: The remainder of this article. Trioxygen ( O 3 ) is usually known as ozone and is a very reactive allotrope of oxygen that is damaging to lung tissue. Ozone is produced in the upper atmosphere when O 2 combines with atomic oxygen made by the splitting of O 2 by ultraviolet (UV) radiation. Since ozone absorbs strongly in the UV region of the spectrum , the ozone layer of
21060-431: The same goals. Viruses play an important role as vectors for inserting genetic information into other organisms. This use is especially relevant to human gene therapy . There are proposals to remove the virulent genes from viruses to create vaccines. Plants have been engineered for scientific research, to create new colors in plants, deliver vaccines, and to create enhanced crops. Genetically modified crops are publicly
21222-442: The same processes as bacteria. For industrial applications, yeasts combine the bacterial advantages of being a single-celled organism that is easy to manipulate and grow with the advanced protein modifications found in eukaryotes . They can be used to produce large complex molecules for use in food, pharmaceuticals, hormones, and steroids. Yeast is important for wine production and as of 2016 two genetically modified yeasts involved in
21384-414: The seawater left behind tends to be higher in oxygen-18. Marine organisms then incorporate more oxygen-18 into their skeletons and shells than they would in a warmer climate. Paleoclimatologists also directly measure this ratio in the water molecules of ice core samples as old as hundreds of thousands of years. Planetary geologists have measured the relative quantities of oxygen isotopes in samples from
21546-474: The spread of the bacteria. The bacteria that naturally colonize certain crops have also been modified, in some cases to express the Bt genes responsible for pest resistance. Pseudomonas strains of bacteria cause frost damage by nucleating water into ice crystals around themselves. This led to the development of ice-minus bacteria , which have the ice-forming genes removed. When applied to crops they can compete with
21708-460: The status of gene-edited organisms. The definition of a genetically modified organism (GMO) is not clear and varies widely between countries, international bodies, and other communities. At its broadest, the definition of a GMO can include anything that has had its genes altered, including by nature. Taking a less broad view, it can encompass every organism that has had its genes altered by humans, which would include all crops and livestock. In 1993,
21870-419: The synonym living modified organism ( LMO ) in 2000 and defined it as "any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology." Modern biotechnology is further defined as "In vitro nucleic acid techniques, including recombinant deoxyribonucleic acid (DNA) and direct injection of nucleic acid into cells or organelles, or fusion of cells beyond
22032-435: The target animals infertile through immunocontraception have been created in the laboratory as well as others that target the developmental stage of the animal. There are concerns with using this approach regarding virus containment and cross species infection. Sometimes the same virus can be modified for contrasting purposes. Genetic modification of the myxoma virus has been proposed to conserve European wild rabbits in
22194-574: The taxonomic family." Originally, the term GMO was not commonly used by scientists to describe genetically engineered organisms until after usage of GMO became common in popular media. The United States Department of Agriculture (USDA) considers GMOs to be plants or animals with heritable changes introduced by genetic engineering or traditional methods, while GEO specifically refers to organisms with genes introduced, eliminated, or rearranged using molecular biology, particularly recombinant DNA techniques, such as transgenesis . The definitions focus on
22356-475: The third-most abundant element in the universe after hydrogen and helium . At standard temperature and pressure , two oxygen atoms will bind covalently to form dioxygen , a colorless and odorless diatomic gas with the chemical formula O 2 . Dioxygen gas currently constitutes 20.95% molar fraction of the Earth's atmosphere , though this has changed considerably over long periods of time in Earth's history . Oxygen makes up almost half of
22518-551: The toad Xenopus laevis in 1974, creating the first GMO expressing a gene from an organism of a different kingdom . In 1974, Rudolf Jaenisch created a transgenic mouse by introducing foreign DNA into its embryo, making it the world's first transgenic animal. However it took another eight years before transgenic mice were developed that passed the transgene to their offspring. Genetically modified mice were created in 1984 that carried cloned oncogenes , predisposing them to developing cancer. Mice with genes removed (termed
22680-486: The universe, after hydrogen and helium. About 0.9% of the Sun 's mass is oxygen. Oxygen constitutes 49.2% of the Earth's crust by mass as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust . It is also the major component of the world's oceans (88.8% by mass). Oxygen gas is the second most common component of the Earth's atmosphere , taking up 20.8% of its volume and 23.1% of its mass (some 10 tonnes). Earth
22842-401: The unpaired electrons in the molecule, and the negative exchange energy between neighboring O 2 molecules. Liquid oxygen is so magnetic that, in laboratory demonstrations, a bridge of liquid oxygen may be supported against its own weight between the poles of a powerful magnet. Singlet oxygen is a name given to several higher-energy species of molecular O 2 in which all
23004-435: The upper atmosphere functions as a protective radiation shield for the planet. Near the Earth's surface, it is a pollutant formed as a by-product of automobile exhaust . At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft . The metastable molecule tetraoxygen ( O 4 ) was discovered in 2001, and was assumed to exist in one of the six phases of solid oxygen . It
23166-451: The vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philo's work by observing that a portion of air is consumed during combustion and respiration . In the late 17th century, Robert Boyle proved that air is necessary for combustion. English chemist John Mayow (1641–1679) refined this work by showing that fire requires only
23328-465: The virulent genes removed. This does not affect the viruses infectivity , invokes a natural immune response and there is no chance that they will regain their virulence function, which can occur with some other vaccines. As such they are generally considered safer and more efficient than conventional vaccines, although concerns remain over non-target infection, potential side effects and horizontal gene transfer to other viruses. Another potential approach
23490-428: Was HO, leading to the conclusion that the atomic mass of oxygen was 8 times that of hydrogen, instead of the modern value of about 16. In 1805, Joseph Louis Gay-Lussac and Alexander von Humboldt showed that water is formed of two volumes of hydrogen and one volume of oxygen; and by 1811 Amedeo Avogadro had arrived at the correct interpretation of water's composition, based on what is now called Avogadro's law and
23652-484: Was determined that light could be produced from extracts with seawater, and more specifically, with calcium . It was also noted during the extraction the animal creates green light due to the presence of the green fluorescent protein , which changes the native blue light of aequorin to green. While the main focus of his work was on the bioluminescence, Shimomura and two others, Martin Chalfie and Roger Tsien , were awarded
23814-408: Was first discovered by Swedish pharmacist Carl Wilhelm Scheele . He had produced oxygen gas by heating mercuric oxide (HgO) and various nitrates in 1771–72. Scheele called the gas "fire air" because it was then the only known agent to support combustion. He wrote an account of this discovery in a manuscript titled Treatise on Air and Fire , which he sent to his publisher in 1775. That document
23976-451: Was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx . Highly combustible materials that leave little residue , such as wood or coal, were thought to be made mostly of phlogiston; non-combustible substances that corrode, such as iron, contained very little. Air did not play a role in phlogiston theory, nor were any initial quantitative experiments conducted to test
24138-491: Was independently developed in 1895 by German engineer Carl von Linde and British engineer William Hampson . Both men lowered the temperature of air until it liquefied and then distilled the component gases by boiling them off one at a time and capturing them separately. Later, in 1901, oxyacetylene welding was demonstrated for the first time by burning a mixture of acetylene and compressed O 2 . This method of welding and cutting metal later became common. In 1923,
24300-408: Was later discovered that the apoprotein can stably bind coelenterazine-2-hydroperoxide, and oxygen is required for the regeneration to this active form of aequorin. However, in the presence of calcium ions, the protein undergoes a conformational change and converts its prosthetic group, coelenterazine-2-hydroperoxide, into excited coelenteramide and CO 2 . As the excited coelenteramide relaxes to
24462-406: Was made by engineering M13 bacteriaophages so they would coat themselves in iron phosphate and then assemble themselves along a carbon nanotube . This created a highly conductive medium for use in a cathode, allowing energy to be transferred quickly. They could be constructed at lower temperatures with non-toxic chemicals, making them more environmentally friendly. Fungi can be used for many of
24624-445: Was no overall increase in weight when tin and air were heated in a closed container. He noted that air rushed in when he opened the container, which indicated that part of the trapped air had been consumed. He also noted that the tin had increased in weight and that increase was the same as the weight of the air that rushed back in. This and other experiments on combustion were documented in his book Sur la combustion en général , which
24786-462: Was not sensibly different from that of common air , but I fancied that my breast felt peculiarly light and easy for some time afterwards." Priestley published his findings in 1775 in a paper titled "An Account of Further Discoveries in Air", which was included in the second volume of his book titled Experiments and Observations on Different Kinds of Air . Because he published his findings first, Priestley
24948-408: Was proven in 2006 that this phase, created by pressurizing O 2 to 20 GPa , is in fact a rhombohedral O 8 cluster . This cluster has the potential to be a much more powerful oxidizer than either O 2 or O 3 and may therefore be used in rocket fuel . A metallic phase was discovered in 1990 when solid oxygen is subjected to a pressure of above 96 GPa and it
25110-499: Was published in 1777. In the meantime, on August 1, 1774, an experiment conducted by the British clergyman Joseph Priestley focused sunlight on mercuric oxide contained in a glass tube, which liberated a gas he named "dephlogisticated air". He noted that candles burned brighter in the gas and that a mouse was more active and lived longer while breathing it. After breathing the gas himself, Priestley wrote: "The feeling of it to my lungs
25272-458: Was published in 1777. In that work, he proved that air is a mixture of two gases; 'vital air', which is essential to combustion and respiration, and azote (Gk. ἄζωτον "lifeless"), which did not support either. Azote later became nitrogen in English, although it has kept the earlier name in French and several other European languages. Lavoisier renamed 'vital air' to oxygène in 1777 from
25434-420: Was shown in 1998 that at very low temperatures, this phase becomes superconducting . Oxygen dissolves more readily in water than nitrogen, and in freshwater more readily than in seawater. Water in equilibrium with air contains approximately 1 molecule of dissolved O 2 for every 2 molecules of N 2 (1:2), compared with an atmospheric ratio of approximately 1:4. The solubility of oxygen in water
25596-470: Was the GloFish (2003) and the first genetically modified animal to be approved for food use was the AquAdvantage salmon in 2015. Bacteria are the easiest organisms to engineer and have been used for research, food production, industrial protein purification (including drugs), agriculture, and art. There is potential to use them for environmental purposes or as medicine. Fungi have been engineered with much
25758-529: Was the definition provided by the Food and Agriculture Organization , the World Health Organization , and the European Commission , stating that the organisms must be altered in a way that does "not occur naturally by mating and/or natural recombination ". Progress in science, such as the discovery of horizontal gene transfer being a relatively common natural phenomenon, further added to
25920-562: Was the lead case. On February 21, 2019, the United States Court of Appeals for the Second Circuit ruled that the FTC and the state of New York could proceed with their lawsuit against Quincy Bioscience for its claims that Prevagen can improve memory. The order came less than two weeks after the parties argued the case before a three-judge panel of the circuit, where company lawyers admitted they did not "dispute that if you look across
26082-406: Was to produce the protein insulin to treat diabetes . Other medicines produced include clotting factors to treat hemophilia , human growth hormone to treat various forms of dwarfism , interferon to treat some cancers, erythropoietin for anemic patients, and tissue plasminogen activator which dissolves blood clots. Outside of medicine they have been used to produce biofuels . There
26244-461: Was unable to demonstrate a classical luciferase - luciferin reaction, he showed that water could produce light from dried photocytes and that light could be produced even in the absence of oxygen. Later, Osamu Shimomura began work into the bioluminescence of Aequorea in 1961. This involved tedious harvesting of tens of thousands of jellyfish from the docks in Friday Harbor, Washington . It
#500499