Everything about Genetically Modified Organism totally explained
A
genetically modified organism (GMO) or
genetically engineered organism (GEO) is an
organism whose
genetic material has been
altered using
genetic engineering techniques. These techniques are generally known as
recombinant DNA technology. With recombinant
DNA technology, DNA
molecules from different sources are combined
in vitro into one molecule to create a new gene. This DNA is then transferred into an organism and causes the expression of modified or novel traits.
History
The general principle of producing a GMO is to introduce new genetic material into an organism's
genome to generate new
traits. This process,
genetic engineering was made possible through a series of scientific advances, including the discovery of
DNA and the creation of the first recombinant
bacteria in 1973. This led to concerns in the scientific community about potential risks from genetic engineering which have been thoroughly discussed at the
Asilomar Conference in Pacific Grove, California. The recommendations laid out from this meeting were that government oversight of recombinant DNA research should be established until the technology was deemed safe.
Herbert Boyer then founded the first company to use recombinant DNA technology,
Genentech, and in 1978 the company announced the creation of an
E. coli strain producing the human protein
insulin.
In 1986, field tests of bacteria genetically engineered to protect plants from frost damage (
ice-minus bacteria) at a small biotechnology company called Advanced Genetic Sciences of
Oakland,
California, were repeatedly delayed by opponents of biotechnology. In the same year, a proposed field test of a microbe genetically engineered for a pest resistance protein by
Monsanto was dropped.
(External Link
)
Uses of GMOs
Examples of GMOs are highly diverse, and include transgenic (genetically modified by recombinant DNA methods)
animals such as
mice, fish,
transgenic plants, or various
microbes, such as fungi and
bacteria. The generation and use of GMOs has many reasons, chief among them are their use in research that addresses fundamental or applied questions in biology or medicine, for the production of
pharmaceuticals and industrial enzymes, and for direct, and often controversial, applications aimed at improving human health (for example,
gene therapy) or agriculture (for example,
golden rice). The term "genetically modified organism" doesn't always imply, but can include, targeted insertions of genes from one into another
species. For example, a gene from a jellyfish, encoding a
fluorescent protein called
GFP, can be physically linked and thus co-expressed with mammalian genes to identify the location of the protein encoded by the GFP-tagged gene in the mammalian cell. These and other methods are useful and indispensable tools for
biologists in many areas of research, including those that study the mechanisms of human and other diseases or fundamental biological processes in
eukaryotic or
prokaryotic cells.
Transgenic microbes
The technology for transgenic microbes has existed for years, and has seen limited use in medicine. Genetically modified bacteria can be used to produce insulin which can be used for diabetics. Genetically modified bacteria is also used in soils to facilitate crop growth, and can also produce chemicals which are toxic to crop pests. Recently, GM bacteria research has moved from crops to people. For instance, the bacteria in your mouth which causes tooth decay is called Streptococcus mutans. This bacteria eats left over sugars in your mouth and produces acid that eats away tooth enamel and causes cavities. Scientists have recently modified Streptococcus mutans to produce ethanol. This transgenic bacterium, if properly colonized in a person's mouth, could eliminate cavities and other tooth related issues. Transgenic microbes have also been used in recent research to kill or hinder tumors, and fight Crohn's disease.
Genetically modified viruses could also have great medical ramifications in the near future. Gene therapy is a relatively new idea in medicine. The basic concept draws upon the natural process of a virus. A virus reproduces by injecting its own genetic material into an existing cell. That cell then produces more viruses based upon the genetic instructions provided by the original virus. Although gene therapy is still relatively new, it has had some successes. Gene therapy has been used to treat severe immunodeficiency. Gene therapy has also been used to some success to treat other genetic disorders such as Cystic Fibrosis, Sickle Cell Anemia, and Muscular Dystrophy. Genetically modifying viruses could be a good tool in gene therapy, but isn't the only development required. Viruses won't insert their genes into every cell, which means that one cell with unhealthy DNA in it'll continue to reproduce and the individual will still have the disease. When a virus's DNA is removed from it and the virus is made into more of a microbial syringe, no new viruses are produced and this limits the spread and duration of treatment, making treatment an ongoing process.
Transgenic animals
Transgenic animals are used as experimental models to perform
phenotypic tests with genes whose function is unknown or to generate animals that are susceptible to certain compounds or stresses for testing in biomedical research. Other applications include the production of human hormones, such as
insulin.
Frequently used in genetic research are transgenic fruit flies (
Drosophila melanogaster) as genetic models to study the effects of genetic changes on development. Flies are often preferred over other animals for ease of culture, and also because the fly genome is somewhat simpler than that of
vertebrates. Transgenic mice are often used to study cellular and tissue-specific responses to disease.
Transgenic plants
Transgenic plants have been developed for various purposes: resistance to pests, herbicides or harsh environmental conditions; improved shelflife; increased nutritional value - and many more. Since the first commercial cultivation of GM plants in 1996, GM plant events tolerant to the herbicides
glufosinate or
glyphosate and events producing the
Bt toxin, an insecticide, have dominated the market. Recently, a new generation of GM plants promising benefits for consumers and industry purposes is becoming ready to enter the markets.
Since GM plants are grown on open fields, there's often a perception that there could be associated environmental risks. Therefore, most countries require biosafety studies prior to the approval of a new GM plant event, usually followed by a monitoring programme to detect environmental impacts.
Especially in Europe, the
coexistence of GM plants with conventional and organic crops has raised many concerns. Since there's separate legislation for GM crops and a high demand from consumers for the freedom of choice between GM and non-GM foods, measures are required to separate GM, conventional and organic plants and derived food and feed. European research programmes such as
Co-Extra, Transcontainer and SIGMEA are investigating appropriate tools and rules. On the field level, these are
biological containment methods,
isolation distances and
pollen barriers.
Controversy over GMOs
Government support for and ban of GMOs
The use of GMOs has sparked significant controversy in many areas
(External Link
). Some groups or individuals see the generation and use of GMO as intolerable meddling with biological states or processes that have naturally evolved over long periods of time, while others are concerned about the limitations of modern science to fully comprehend all of the potential negative ramifications of genetic manipulation.
While some groups advocate the complete prohibition of GMOs, others call for mandatory labeling of
genetically modified food or other products. Other controversies include the definition of patent and property pertaining to products of genetic engineering and the possibility of unforeseen local and global effects as a result of transgenic organisms proliferating. The basic ethical issues involved in genetic research are discussed in the article on
genetic engineering.
USA
In 2004,
Mendocino County,
California became the first county in the
United States to ban the production of GMOs. The measure passed with a 57% majority. In California,
Trinity and
Marin counties have also imposed bans on GM crops, while ordinances to do so were unsuccessful in
Butte,
San Luis Obispo,
Humboldt, and
Sonoma counties. Supervisors in the
agriculturally-rich counties of
Fresno,
Kern,
Kings,
Solano,
Sutter, and
Tulare have passed resolutions supporting the practice
(External Link
).
Canada
In 2005, a
standing committee of the government of
Prince Edward Island in
Canada began work to assess a proposal to ban the production of GMOs in the province. PEI has already banned GM potatoes, which account for most of its crop. Mainland Canada is one of the worlds largest producers of GM canola.
Australia
Several states of Australia have had moratoria on the planting of GM food crops dating from around 2003 . However, in late 2007 the states of New South Wales and Victoria lifted these bans while South Australia and Western Australia continued their bans . Tasmania has extended their moritorium to June 2008 The state of Queensland has allowed the growing of GM crops since 1995 and has never had a GM ban.
Currently, there's little international consensus regarding the acceptability and effective role of modified "complete" organisms such as plants or animals. A great deal of the modern research that's illuminating complex biochemical processes and disease mechanisms makes vast use of genetic engineering.
Crosspollination concerns
Some critics have raised the concern that conventionally bred crop plants can be cross-pollinated (bred) from the pollen of modified plants. Pollen can be dispersed over large areas by wind, animals, and insects. Recent research with creeping bentgrass has lent support to the concern when modified genes were found in normal grass up to 21 km (13 miles) away from the source, and also within close relatives of the same genus (
Agrostis)
(External Link
). GM proponents point out that
outcrossing, as this process is known, isn't new. The same thing happens with any new open-pollinated crop variety—newly introduced traits can potentially cross out into neighbouring crop plants of the same species and, in some cases, to closely related wild relatives. Defenders of GM technology point out that each GM crop is assessed on a case by case basis to determine if there's any risk associated with the outcrossing of the GM trait into wild plant populations. The fact that a GM plant may outcross with a related wild relative is not, in itself, a risk unless such an occurrence has consequences. If, for example, a herbicide resistance trait was to cross into a wild relative of a crop plant it can be predicted that this wouldn't have any consequences except in areas where herbicides are sprayed, such as a farm. In such a setting the farmer can manage this risk by rotating herbicides.
The European Union funds research programmes such as
Co-Extra, that investigate options and technologies on the coexistence of GM and conventional farming. This also includes research on biological containment strategies and other measures, that prevent outcrossing and enable the implementation of coexistence.
If patented genes are outcrossed, even accidentally, to other commercial fields and a person deliberately selects the outcrossed plants for subsequent planting then the patent holder has the right to control the use of those crops. This was supported in
Canadian law in the case of
Monsanto Canada Inc. v. Schmeiser.
'Terminator' and 'traitor'
An often cited controversy is a hypothetical "Technology Protection" technology dubbed 'Terminator'
(External Link
). This yet-to-be-
commercialized technology would allow the production of first generation crops that wouldn't generate seeds in the second generation because the plants yield sterile
seeds. The patent for this so-called "terminator" gene technology is owned by Delta and Pine Land and the
United States Department of Agriculture. Delta and Pine Land was bought by
Monsanto in August 2006. Similarly, the hypothetical Trait-specific Genetic Use Restriction Technology, also known as 'Traitor' or 'T-gut', requires application of a chemical to genetically-modified crops to reactivate engineered traits
(External Link
)(External Link
). This technology is intended both to limit the spread of genetically engineered plants, and to require farmers to pay yearly to reactivate the genetically engineered traits of their crops. Traitor is under development by companies including Monsanto and AstraZeneca.
In addition to the commercial protection of proprietary technology in self-pollinating crops such as
soybean (a generally contentious issue) another purpose of the terminator gene is to prevent the escape of genetically modified traits from crosspollinating crops into wild-type species by sterilizing any resultant hybrids. The terminator gene technology created a backlash amongst those who felt the technology would prevent re-use of seed by farmers growing such terminator varieties in the developing world and was ostensibly a means to exercise
patent claims. Use of the terminator technology would also prevent "volunteers", or crops that grow from unharvested seed, a major concern that arose during the
Starlink debacle. There are technologies evolving which contain the transgene by biological means and still can provide fertile seeds using fertility restorer functions. Such methods are being developed by several EU research programmes, among them Transcontainer and
Co-Extra.
Further Information
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