Genetic engineering, also called genetic modification, is the direct manipulation of an organism's genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of
genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially
synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with
the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.
An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is agenetically modified organism (GMO). The first GMO was a bacterium generated by Herbert
Boyer and Stanley Cohen in 1973.Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, Genentech, was founded in 1976 and
started the production of human proteins. Genetically engineered humaninsulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold since 1994, with the
release of the Flavr Savr tomato. The Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet,
was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.
Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of
function, tracking and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines and other
drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry
detergent, cheeses and other products.
The rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has also been the source of most of the controversy surrounding the technology. This has been
present since its early use, the first field trials were destroyed by anti-GM activists. 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 is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues. These
concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed
their own regulatory systems regarding GMOs, with the most marked differences occurring between the USA and Europe.
Contents
[hide]
1Overview
2History
3Process
o 3.1Gene isolation and cloning
o 3.2Inserting DNA into the host genome
4Applications
o 4.1Medicine
o 4.2Research
o 4.3Industrial
o 4.4Agriculture
o 4.5Other applications
5Regulation
6Controversy
7See also
8References
9Further reading
10External links
Overview[edit]
Comparison of conventional plant breeding with transgenic andcisgenic genetic modification
Genetic engineering is a process that alters the genetic make-up of an organism by either removing or introducingDNA. Unlike traditionally animal and plant breeding, which involves doing multiple crosses and then selecting for
the organism with the desired phenotype, genetic engineering takes the gene directly from one organism and inserts it in the other. This is much faster, can be used to insert any genes from any organism (even ones from
different domains) and prevents other undesirable genes from also being added.[1]
Genetic engineering could potentially fix severe genetic disorders in humans by replacing the defective gene with a functioning one.[2] It is an important tool in research that allows the function of specific genes to be studied.
[3]
Drugs, vaccines and other products have been harvested from organisms engineered to produce them.[4] Cropshave been developed that aid food security by increasing yield, nutritional value and tolerance to environmental
stresses.[5]
, The DNA can be introduced directly into the host organism or into a cell that is then fused or hybridised with the host.[6] This relies on recombinant nucleic acid techniques to form new combinations of heritable genetic material
followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection or micro-encapsulation.[7]
Genetic engineering does not normally include traditional breeding, in vitro fertilisation, induction of polyploidy,mutagenesis and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism
in the process.[6] However, some broad definitions of genetic engineering include selective breeding.[7]Cloning and stem cell research, although not considered genetic engineering,[8] are closely related and genetic engineering
can be used within them.[9] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism.[10]
Plants, animals or micro organisms that have been changed through genetic engineering are termed genetically modified organisms or GMOs.[11] If genetic material from another species is added to the host, the resulting
organism is called transgenic. If genetic material from the same species or a species that can naturally breed with the host is used the resulting organism is called cisgenic.[12] If genetic engineering is used to remove genetic
material from the target organism the resulting organism is termed a knockoutorganism.[13] In Europe genetic modification is synonymous with genetic engineering while within the United States of America and Canada genetic
modification can also be used to refer to more conventional breeding methods.[14][15][16]
International Union of Pure and Applied Chemistry definition of genetic engineering
Process of inserting new genetic information into existing cells in order to modify a specific organism for the purpose of changing its characteristics. Note: Adapted from ref.[17][18]
History[edit]
Main article: History of genetic engineering
Humans have altered the genomes of species for thousands of years through selective breeding, or artificial selection[19]:1[20]:1 as contrasted with natural selection, and more recently through mutagenesis. Genetic engineering as
the direct manipulation of DNA by humans outside breeding and mutations has only existed since the 1970s. The term "genetic engineering" was first coined by Jack Williamson in his science fiction novel Dragon's Island,
published in 1951[21] – one year before DNA's role in heredity was confirmed by Alfred Hershey and Martha Chase,[22] and two years before James Watson and Francis Crick showed that the DNA molecule has a double-helix
structure – though the general concept of direct genetic manipulation was explored in rudimentary form in Stanley G. Weinbaum's 1936 science fiction story Proteus Island.[23][24]
In 1974 Rudolf Jaenisch created agenetically modified mouse, the first GM animal.
In 1972, Paul Berg created the first recombinant DNA molecules by combining DNA from the monkey virus SV40 with that of the lambda virus.[25] In 1973 Herbert Boyer and Stanley Cohen created the first transgenic organism by
inserting antibiotic resistance genes into theplasmid of an Escherichia coli bacterium.[26][27] A year later Rudolf Jaenisch created a transgenic mouse by introducing foreign DNA into its embryo, making it the world’s first transgenic
animal.[28] These achievements led to concerns in the scientific community about potential risks from genetic engineering, which were first discussed in depth at the Asilomar Conference in 1975. One of the main
recommendations from this meeting was that government oversight of recombinant DNA research should be established until the technology was deemed safe.[29][30]
In 1976 Genentech, the first genetic engineering company, was founded by Herbert Boyer and Robert Swanson and a year later the company produced a human protein (somatostatin) in E.coli. Genentech announced the
production of genetically engineered humaninsulin in 1978.[31] In 1980, the U.S. Supreme Court in the Diamond v. Chakrabarty case ruled that genetically altered life could be patented.[32] The insulin produced by bacteria was
approved for release by the Food and Drug Administration (FDA) in 1982.[33]
In 1983, a biotech company, Advanced Genetic Sciences (AGS) applied for U.S. government authorisation to perform field tests with theice-minus strain of Pseudomonas syringae to protect crops from frost, but environmental
groups and protestors delayed the field tests for four years with legal challenges.[34] In 1987, the ice-minus strain of P. syringae became the first genetically modified organism (GMO) to be released into the environment[35] when a
strawberry field and a potato field in California were sprayed with it.[36] Both test fields were attacked by activist groups the night before the tests occurred: "The world's first trial site attracted the world's first field trasher". [35]
The first field trials of genetically engineered plants occurred in France and the USA in 1986, tobacco plants were engineered to be resistant to herbicides.[37] The People’s Republic of China was the first country to commercialise
transgenic plants, introducing a virus-resistant tobacco in 1992.[38] In 1994 Calgene attained approval to commercially release the first genetically modified food, the Flavr Savr, a tomato engineered to have a longer shelf life.[39] In
1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil, making it the first genetically engineered crop commercialised in Europe.[40] In 1995, Bt Potato was approved safe by
the Environmental Protection Agency, after having been approved by the FDA, making it the first pesticide producing crop to be approved in the USA.[41] In 2009 11 transgenic crops were grown commercially in 25 countries, the
largest of which by area grown were the USA, Brazil, Argentina, India, Canada, China, Paraguay and South Africa.[42]
In 2010, scientists at the J. Craig Venter Institute created the first synthetic genome and inserted it into an empty bacterial cell. The resulting bacterium, named Mycoplasma laboratorium, could replicate and produce proteins.[43]
[44]
Four years later this was taken a step further when bacterium was developed that replicated a plasmid containing a unique base pair, creating the first organism engineered to use an expanded genetic alphabet.[45][46] In
2012, Jennifer Doudna and Emmanuelle Charpentier collaborated to develop the CRISPR/Cas9 system,[47][48] a technique which can be used to easily and specifically alter the genome of almost any organism.[49]
Process[edit]
Main article: Genetic engineering techniques
genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially
synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with
the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.
An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is agenetically modified organism (GMO). The first GMO was a bacterium generated by Herbert
Boyer and Stanley Cohen in 1973.Rudolf Jaenisch created the first GM animal when he inserted foreign DNA into a mouse in 1974. The first company to focus on genetic engineering, Genentech, was founded in 1976 and
started the production of human proteins. Genetically engineered humaninsulin was produced in 1978 and insulin-producing bacteria were commercialised in 1982. Genetically modified food has been sold since 1994, with the
release of the Flavr Savr tomato. The Flavr Savr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides. GloFish, the first GMO designed as a pet,
was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.
Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture. In research GMOs are used to study gene function and expression through loss of function, gain of
function, tracking and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines and other
drugs genetic engineering has the potential to cure genetic diseases through gene therapy. The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry
detergent, cheeses and other products.
The rise of commercialised genetically modified crops has provided economic benefit to farmers in many different countries, but has also been the source of most of the controversy surrounding the technology. This has been
present since its early use, the first field trials were destroyed by anti-GM activists. 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 is a leading concern with critics. Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues. These
concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed
their own regulatory systems regarding GMOs, with the most marked differences occurring between the USA and Europe.
Contents
[hide]
1Overview
2History
3Process
o 3.1Gene isolation and cloning
o 3.2Inserting DNA into the host genome
4Applications
o 4.1Medicine
o 4.2Research
o 4.3Industrial
o 4.4Agriculture
o 4.5Other applications
5Regulation
6Controversy
7See also
8References
9Further reading
10External links
Overview[edit]
Comparison of conventional plant breeding with transgenic andcisgenic genetic modification
Genetic engineering is a process that alters the genetic make-up of an organism by either removing or introducingDNA. Unlike traditionally animal and plant breeding, which involves doing multiple crosses and then selecting for
the organism with the desired phenotype, genetic engineering takes the gene directly from one organism and inserts it in the other. This is much faster, can be used to insert any genes from any organism (even ones from
different domains) and prevents other undesirable genes from also being added.[1]
Genetic engineering could potentially fix severe genetic disorders in humans by replacing the defective gene with a functioning one.[2] It is an important tool in research that allows the function of specific genes to be studied.
[3]
Drugs, vaccines and other products have been harvested from organisms engineered to produce them.[4] Cropshave been developed that aid food security by increasing yield, nutritional value and tolerance to environmental
stresses.[5]
, The DNA can be introduced directly into the host organism or into a cell that is then fused or hybridised with the host.[6] This relies on recombinant nucleic acid techniques to form new combinations of heritable genetic material
followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection or micro-encapsulation.[7]
Genetic engineering does not normally include traditional breeding, in vitro fertilisation, induction of polyploidy,mutagenesis and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism
in the process.[6] However, some broad definitions of genetic engineering include selective breeding.[7]Cloning and stem cell research, although not considered genetic engineering,[8] are closely related and genetic engineering
can be used within them.[9] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism.[10]
Plants, animals or micro organisms that have been changed through genetic engineering are termed genetically modified organisms or GMOs.[11] If genetic material from another species is added to the host, the resulting
organism is called transgenic. If genetic material from the same species or a species that can naturally breed with the host is used the resulting organism is called cisgenic.[12] If genetic engineering is used to remove genetic
material from the target organism the resulting organism is termed a knockoutorganism.[13] In Europe genetic modification is synonymous with genetic engineering while within the United States of America and Canada genetic
modification can also be used to refer to more conventional breeding methods.[14][15][16]
International Union of Pure and Applied Chemistry definition of genetic engineering
Process of inserting new genetic information into existing cells in order to modify a specific organism for the purpose of changing its characteristics. Note: Adapted from ref.[17][18]
History[edit]
Main article: History of genetic engineering
Humans have altered the genomes of species for thousands of years through selective breeding, or artificial selection[19]:1[20]:1 as contrasted with natural selection, and more recently through mutagenesis. Genetic engineering as
the direct manipulation of DNA by humans outside breeding and mutations has only existed since the 1970s. The term "genetic engineering" was first coined by Jack Williamson in his science fiction novel Dragon's Island,
published in 1951[21] – one year before DNA's role in heredity was confirmed by Alfred Hershey and Martha Chase,[22] and two years before James Watson and Francis Crick showed that the DNA molecule has a double-helix
structure – though the general concept of direct genetic manipulation was explored in rudimentary form in Stanley G. Weinbaum's 1936 science fiction story Proteus Island.[23][24]
In 1974 Rudolf Jaenisch created agenetically modified mouse, the first GM animal.
In 1972, Paul Berg created the first recombinant DNA molecules by combining DNA from the monkey virus SV40 with that of the lambda virus.[25] In 1973 Herbert Boyer and Stanley Cohen created the first transgenic organism by
inserting antibiotic resistance genes into theplasmid of an Escherichia coli bacterium.[26][27] A year later Rudolf Jaenisch created a transgenic mouse by introducing foreign DNA into its embryo, making it the world’s first transgenic
animal.[28] These achievements led to concerns in the scientific community about potential risks from genetic engineering, which were first discussed in depth at the Asilomar Conference in 1975. One of the main
recommendations from this meeting was that government oversight of recombinant DNA research should be established until the technology was deemed safe.[29][30]
In 1976 Genentech, the first genetic engineering company, was founded by Herbert Boyer and Robert Swanson and a year later the company produced a human protein (somatostatin) in E.coli. Genentech announced the
production of genetically engineered humaninsulin in 1978.[31] In 1980, the U.S. Supreme Court in the Diamond v. Chakrabarty case ruled that genetically altered life could be patented.[32] The insulin produced by bacteria was
approved for release by the Food and Drug Administration (FDA) in 1982.[33]
In 1983, a biotech company, Advanced Genetic Sciences (AGS) applied for U.S. government authorisation to perform field tests with theice-minus strain of Pseudomonas syringae to protect crops from frost, but environmental
groups and protestors delayed the field tests for four years with legal challenges.[34] In 1987, the ice-minus strain of P. syringae became the first genetically modified organism (GMO) to be released into the environment[35] when a
strawberry field and a potato field in California were sprayed with it.[36] Both test fields were attacked by activist groups the night before the tests occurred: "The world's first trial site attracted the world's first field trasher". [35]
The first field trials of genetically engineered plants occurred in France and the USA in 1986, tobacco plants were engineered to be resistant to herbicides.[37] The People’s Republic of China was the first country to commercialise
transgenic plants, introducing a virus-resistant tobacco in 1992.[38] In 1994 Calgene attained approval to commercially release the first genetically modified food, the Flavr Savr, a tomato engineered to have a longer shelf life.[39] In
1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil, making it the first genetically engineered crop commercialised in Europe.[40] In 1995, Bt Potato was approved safe by
the Environmental Protection Agency, after having been approved by the FDA, making it the first pesticide producing crop to be approved in the USA.[41] In 2009 11 transgenic crops were grown commercially in 25 countries, the
largest of which by area grown were the USA, Brazil, Argentina, India, Canada, China, Paraguay and South Africa.[42]
In 2010, scientists at the J. Craig Venter Institute created the first synthetic genome and inserted it into an empty bacterial cell. The resulting bacterium, named Mycoplasma laboratorium, could replicate and produce proteins.[43]
[44]
Four years later this was taken a step further when bacterium was developed that replicated a plasmid containing a unique base pair, creating the first organism engineered to use an expanded genetic alphabet.[45][46] In
2012, Jennifer Doudna and Emmanuelle Charpentier collaborated to develop the CRISPR/Cas9 system,[47][48] a technique which can be used to easily and specifically alter the genome of almost any organism.[49]
Process[edit]
Main article: Genetic engineering techniques
