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A genetically modified organism (GMO) is an organism whose genetic material
has been altered using the genetic engineering techniques generally known as
recombinant DNA technology. With recombinant DNA technology DNA molecules from
different sources are combined in vitro to one molecule to create a new gene.
This modified DNA is then transferred into an organism causing the expression of
modified or novel traits. The product is also known as an Genetically Engineered
Organism or GEO
The term "GMO" has historically been defined as organisms whose genetic makeup
has been altered by conventional cross breeding or by "mutagenesis" breeding, as
these methods predate the discovery of the recombinant DNA techniques. However,
this term is now interchangeable with Genetically Engineered Organism.
History
The general principle of producing a GMO is to add genetic material into an
organism's genome to generate new traits - 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, i.e., E .coli
expressing a salmonella gene. 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 a bacterium 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.
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 (e.g., gene therapy)
or agriculture (e.g., golden rice). The term "genetically modified organism"
does not 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 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 cosmetics and 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 ethical reasons
and ease of culture, and also because the fly genome is somewhat simpler than
that of vertebrates.
Transgenic plants
Kenyans examining insect-resistant transgenic Bt corn.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, they are often associated with
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 is 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. Further down the food chain, documentation and detection
methods shall ensure the coexistence.
Controversy over GMOs
Genetically modified food controversies
Government support for and ban of GMOs
The use of GMOs has sparked significant controversy in many areas . 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.
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
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. 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 .
Currently, there is 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 is illuminating complex biochemical
processes and disease mechanisms makes vast use of genetic engineering.
The practice of genetic modification as a scientific technique is not restricted
in the United States. Individual genetically modified crops (such as soybeans)
are studied before being brought to market, but generally only by the companies
providing the modification. This "test by those being tested" practice is common
in the United States, where many in the FDA are ex-employees of Monsanto, the
largest gene-manipulation firm. Most countries in Europe, Japan, Mexico (among
others) have taken the opposite position, stating that genetic modification has
not been proven safe, and therefore that they will not accept genetically
modified food from the United States or any other country without assessing
their safety themselves. This issue has been brought before the World Trade
Organization, which determined that not allowing GMOs into the country creates
an unnecessary obstacle to international trade. Consequently, genetic
modification within agriculture is an issue of some strong debate in the United
States, the European Union, and some other countries.
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) . GM proponents point out
that outcrossing, as this process is known, is not 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
is 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 would not 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' . This yet-to-be-commercialised technology would allow the
production of first generation crops that would not 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 yearly application of a
chemical to genetically-modified crops to reactivate engineered traits . 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
selfpollinating 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. However, 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.
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