Genetic engineering
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.
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.
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.
Gene flow, impact on non-target organisms, control of the food supply and intellectual property rights have also been raised as potential issues.
[12] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesised material into an organism.
The term "genetic engineering" was coined by the Russian-born geneticist Nikolay Timofeev-Ressovsky in his 1934 paper "The Experimental Production of Mutations", published in the British journal Biological Reviews.
[22] Jack Williamson used the term in his science fiction novel Dragon's Island, published in 1951[23] – one year before DNA's role in heredity was confirmed by Alfred Hershey and Martha Chase,[24] 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.
[27] In 1973 Herbert Boyer and Stanley Cohen created the first transgenic organism by inserting antibiotic resistance genes into the plasmid of an Escherichia coli bacterium.
[40] 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.
[45][46] Four years later this was taken a step further when a bacterium was developed that replicated a plasmid containing a unique base pair, creating the first organism engineered to use an expanded genetic alphabet.
[47][48] In 2012, Jennifer Doudna and Emmanuelle Charpentier collaborated to develop the CRISPR/Cas9 system,[49][50] a technique which can be used to easily and specifically alter the genome of almost any organism.
[52] Luck also plays its part; the Roundup Ready gene was discovered after scientists noticed a bacterium thriving in the presence of the herbicide.
[58] The RK2 plasmid is notable for its ability to replicate in a wide variety of single-celled organisms, which makes it suitable as a genetic engineering tool.
A selectable marker gene is added, which in most cases confers antibiotic resistance, so researchers can easily determine which cells have been successfully transformed.
[61] Plant genomes can be engineered by physical methods or by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors.
[80][81] Genetic engineering has applications in medicine, research, industry and agriculture and can be used on a wide range of plants, animals and microorganisms.
Bacteria, the first organisms to be genetically modified, can have plasmid DNA inserted containing new genes that code for medicines or enzymes that process food and other substrates.
[86] Genetic engineering has many applications to medicine that include the manufacturing of drugs, creation of model animals that mimic human conditions and gene therapy.
[106] In November 2018, He Jiankui announced that he had edited the genomes of two human embryos, to attempt to disable the CCR5 gene, which codes for a receptor that HIV uses to enter cells.
[117] These techniques are used to produce medicines such as insulin, human growth hormone, and vaccines, supplements such as tryptophan, aid in the production of food (chymosin in cheese making) and fuels.
[121] Certain genetically modified microbes can also be used in biomining and bioremediation, due to their ability to extract heavy metals from their environment and incorporate them into compounds that are more easily recoverable.
[122] In materials science, a genetically modified virus has been used in a research laboratory as a scaffold for assembling a more environmentally friendly lithium-ion battery.
Gene transfer through viral vectors has been proposed as a means of controlling invasive species as well as vaccinating threatened fauna from disease.
The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the development and release of GMOs.
[154] The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.
The European Commission says that mandatory labeling and traceability are needed to allow for informed choice, avoid potential false advertising[173] and facilitate the withdrawal of products if adverse effects on health or the environment are discovered.
[180] Other ethical issues raised include the patenting of life,[181] the use of intellectual property rights,[182] the level of labeling on products,[183][184] control of the food supply[185] and the objectivity of the regulatory process.
[191] Other environmental concerns involve potential impacts on non-target organisms, including soil microbes,[192] and an increase in secondary and resistant insect pests.
[214] Frank Herbert's novel The White Plague describes the deliberate use of genetic engineering to create a pathogen which specifically kills women.
In Clark's view, the biotechnology is typically "given fantastic but visually arresting forms" while the science is either relegated to the background or fictionalised to suit a young audience.
