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One of the many applications of modern biotechnology is the use of
GMOs in the food production chain. GMO (Genetically Modified Organisms) means
remove one or more genes from the DNA of another organism, such as a bacterium,
virus, animal, or plant and “recombine” them into the DNA of the plant they
want to alter. Therefore do not fall in the category GMO living beings who have
undergone genetic changes through spontaneous processes and through
intersections, but only those for which it was made use of genetic engineering,
more specifically to the hybridization techniques and selection, mutagenesis
and selection. Genetic modification is based on a theory called the Central
Dogma, which asserts that one gene will express one protein. However,
scientists working with the United States National Human Genome Research
Institute discovered that this wasn’t true, that genes operate in a complex
network in ways that are not fully understood. This finding undermines the
entire basis for genetic engineering. Today, GM foods are as controversial as
ever, particularly given that a large amount of research studies are
conflicting and many have been presented in slanted or exaggerated ways. It is
difficult for the consumer to sort through the barrage of conflicting information.
When a person does not fully understand a concept and has mixed information,
the tendency can also be to want to avoid it entirely. For now though, the best
approach is one of education and information, which will allow you to
contribute to a safer and more positive future of GM foods.
Keyword: GMO, DNA, PCR,
ELECTROPORATION.
INTRODUCTION
Biotechnology
encompasses a wide range of technologies and they can be applied for a range of
different purposes, such as the genetic improvement of plant varieties and
animal populations to increase their yields or efficiency; genetic
characterization and conservation of genetic resources; plant or animal disease
diagnosis; vaccine development; and improvement of feeds. Some of the technologies
may be applied to all the food and agriculture sectors, such as the use of
molecular DNA markers or genetic modification, while others are more
sector-specific, such as tissue culture (in crops and forest trees), embryo
transfer (livestock) or triploidization and sex-reversal (fish). Genetically
modified crops (GMCs, GM crops, or biotech crops) are plants
used in agriculture, the DNA of which has been modified
using genetic engineering techniques. In most cases,
the aim is to introduce a new trait to the plant which does not occur naturally in the species.
- ·
be stronger and avoid the use of
pesticides
- ·
be less susceptible to pollutants (such
as carcinogenic aflatoxin to humans)
- ·
to obtain a better productivity index
- ·
have better nutritional characteristics
(e.g. greater wealth of vitamins or lower content of uninteresting or even
harmful substances).
The
procedure used to produce plant GMO can be simplified into four steps Figure 2:
·
Isolate the genetic trait.
·
Insert the desired genetic trait into a new genome (for example a
bacterial plasmid).
·
Replication of
the plasmid in a bacterium to have more copies of the gene to be transferred.
·
Transfer of
plasmid in a plant species.
The isolation is carried out
by the restriction enzymes which are protein complexes found in some bacterial
strains and are able to cut the DNA at specific sequences of bases, different
for each enzyme, allowing it to fragment the genome in a precise and
reproducible. The cuts may take place within the chain, through the work of the
endonuclease, or ends for the work of exonuclease. The use of these enzymes has
allowed to isolate the individual DNA fragments. Researchers have identified
and use different restriction enzymes, each of which cuts both strands of the
double helix in correspondence with a specific sequence of base pairs. The cuts
are often staggered so that forming fragments provided with single-stranded
ends, said ends sticky or cohesive. Since cutting is always performed at the
same sequence of bases for any DNA molecule, irrespective of its origin
(bacterial, viral, eukaryotic), all the fragments have complementary cohesive
ends, that combine spontaneously.
The techniques that allow the
insertion of a gene or a plasmid in a bacterial cell, plant, animal, or in a
protoplast (ie a private cell wall and / or cell membrane) are varied; some of
them can be used for any cell type while others are specific. The most common
techniques are :
·
The polymerase chain
reaction (PCR)
·
Electroporation
·
Biolistics
·
Calcium Phosphate
Precipitation
Ø
The polymerase chain reaction (PCR)
The Polymerase Chain
Reaction (PCR) [7] is now a very widely used technique for copying DNA.
Starting with only a small sample of DNA, PCR can generate many copies of a
specific DNA segment to be used for further analysis. PCR, requires only the
knowledge of the adjacent sequences (primers) to the fragment to be amplified
and a polymerase resistant to heat. A typical PCR cycle involves four main
stages that are repeated several times:
- Template DNA - the starting DNA of
interest
- Two Primers (oligonucleotides) - short,
single-stranded, synthesized pieces of DNA that complement sequences on
each side of the region of the template DNA that is being amplified
- Thermostable DNA Polymerase -
typically Taq (Thermus aquaticus), a heat stable enzyme capable
of adding nucleotides to a growing DNA strand
- dNTPs - a supply of the 4 nucleotides
needed to make the new DNA strands
- Cationic Magnesium - a cofactor for the
polymerase
- Appropriately Buffered Solution - to
maintain the pH and salt concentrations appropriate for the polymerase
Ø
Electroporation
The prepped target cells are
saturated in a solution with the chosen DNA. A brief but strong electric shock
is transmitted through the solution [8], causing little tears in the walls of
the cells. This allows for the new genetic material to penetrate the nuclei.
Afterwards, the cells are put in a different solution that coaxes the repair of
their walls, which works to 'trap' the DNA of the donor in the cell. The chosen
DNA becomes joined with the host chromosomes to give the host this new gene.
Ø
Biolistics
This technique uses the
chosen DNA to attach it to tiny gold particles. The particles – now 'carrying'
DNA – are forced into the target cells using an intense burst of gas.
Ø
Calcium Phosphate Precipitation
In this biotechnology
technique, the chosen DNA would be exposed to calcium phosphate, which results
in the creation of miniscule granules. The targeted cells react to the granules
by essentially 'swarming' them and ingesting them, thereby facilitating the
granule release of DNA and the subsequent delivery to the host's nuclei and
chromosomes.
The techniques through which
you can obtain genetically modified organisms are relatively recent and
currently available on the market GMOs that have characters that can be
controlled with relative ease; in fact they are inserted one or a few genes
related to a certain characteristic (a typical example is the resistance to a
particular disease); but it must take into account that, over the last decade,
genomics has made great strides and it is very likely that we will see soon
appear on the market GMOs particularly complex genetic modifications.
USEFULNESS OF GM CROPS
Genetically modified
(GM) foods have an interesting history and their development has experienced
rapid growth over the last decade. Within all of the history, there has been a
great deal of controversy and debate about the benefits and risks of GM foods
and the production process. Given the current situation around GM foods, the
controversy will likely continue for some time as well.
Soya - soya has been
genetically modified to increase the amount of the C4 protein, a protein that
gives the plant increased resistance to herbicides.
Corn - There are some
varieties of genetically modified corn.
- One of these, containing the Bacillus thuringiensis (Bt)
genetic material useful in the production of a BT toxin capable of
poisoning pests of the family insects of lepidoptera (moths and
butterflies). Often these varieties of maize are also resistant to several
types of herbicides. The corn is hidden in many prepared foods and
packaged under the name of cornstarch, glucose and fructose. Be very
careful.
Sugar beets - genetically
modified to resist the herbicide used by the US giant Monsanto.
Rice - the genetically
modified to resist herbicides should not yet be available for human
consumption, but some amount of rice (long grain) genetically modified (LLRICE601)
[9] have been included in both the US and Europe. It has recently created a new
rice strain, golden rice, to increase the natural production of beta carotene
that our body uses to make vitamin A. Golden rice is still in the testing phase
and has not yet been determined if the 'the human intake can be dangerous or
not.
In the agricultural field
they have been developed that bacteria introduced in the soil improve its
characteristics and are able to protect them from frost or insects. They then
obtained more resistant plants to various stress, bacteria or viruses, or more
tolerant to certain herbicides.
Where food enzymes are
products used for industrial production and for fermentation processes; They
are then obtained from plants much better organoleptic characteristics and
animal products whose nutritional and organoleptic characteristics are well
above the norm.
HARMFULNESS OF GM CROPS
In the face of the indisputable benefits that could result from the release of GMOs into the environment, they are also evaluate the risks.
Among the major risks cited are those resulting from food safety, which could be jeopardized by the introduction of toxic elements; Furthermore, they may of arising allergies and resistance to drugs in pathogenic organisms. In a study in the early 1990's rats were fed genetically modified (GM) tomatoes. Well actually, the rats refused to eat them. They were force-fed. Several of the rats developed stomach lesions and seven out of forty died within two weeks [6]. Scientists at the FDA who reviewed the study agreed that it did not provide a "demonstration of reasonable certainty of no harm." In fact, agency scientists warned that GM foods in general might create unpredicted allergies, toxins, antibiotic resistant diseases, and nutritional problems. Not insignificant is also the risks arising from the interaction with other organisms, which could give rise to a transfer of genes, the pollution of the genetic basis through the dispersion of seeds or pollen, the transfer of genes in microorganisms (DNA uptake) and finally the generation of new viruses by genetic recombination. GM-fed animals had problems with their growth, organ development and immune responsiveness, blood and liver cell formation, as well as damaged organs, sterility. Risks are increased by the fact that the genes inserted into GM food not only survive digestion, but transfer into body organs and circulation. Transgenes have been found in the blood, liver, spleen and kidneys. DNA can even travel via the placenta into the unborn. According to a July 27, 2004 report from the US National Academy of Sciences (NAS), [7] the current system of blanket approval of GM foods by the FDA might not detect "unintended changes in the composition of the food." The process of gene insertion, according to the NAS, could damage the host's DNA with unpredicted consequences. The Indian Council of Medical Research (ICMR), which released its findings a few days earlier, identified a long list of potentially dangerous side effects from GM foods that are not being evaluated. The ICMR called for a complete overhaul of existing regulations [8]. The only human feeding study ever conducted showed that the gene inserted into soybeans spontaneously transferred out of food and into the DNA of gut bacteria [9]. This has several serious implications. First, it means that the bacteria inside our intestines, newly equipped with this foreign gene, may create the novel protein inside of us. If it is allergenic or toxic, it may affect us for the long term, even if we give up eating GM soy. The same study verified that the promoter, which scientists attach to the inserted gene to permanently switch it on, also transferred to gut bacteria. Research on this promoter suggests that it might unintentionally switch on other genes in the DNA – permanently [10]. This could create an overproduction of allergens, toxins, carcinogens, or antinutrients. Scientists also theorize that the promoter might switch on dormant viruses embedded in the DNA or generate mutations [11]. But in a worldwide there are more than 114 million hectares of crops genetically modified plants, more than half of which are located in the US (51%) while a good 87% of them in the Americas. 99% of the crop is concentrated in a few countries: the US, Canada, South America (Argentina, Brazil and Paraguay), India, China and South Africa. The rice art, crafted from rice plants, shows a map of Italy booting out the GMO (genetically modified organisms) logo. Greenpeace, responsible for the art, is asking the Italian government to keep the country’s rice GMO free and respect the rights for the Italian citizen to be able to have food choice Figure 3.
Applicants can apply for GMO
authorizations by submitting a dossier with experimental data and a risk
assessment. In 1997, FDA established a voluntary consultation process with GM
crop developers to review the determination of “substantial equivalence” before
the crop is marketed, such as assessing the toxicity and allergenicity of the
gene product and the plant itself. If the data in the food-safety assessment
are satisfactory, FDA notifies the developer that marketing of the crop may
proceed. Critics have raised questions about whether this voluntary
consultation process provides adequate assurance that GM crops are safe. In
particular, the use of food crops like corn for the production of non-food
products, such as pharmaceuticals, does not fall under FDA’s authority unless
the gene product ends up contaminating a food crop, at which time the crop is
considered adulterated and must be recalled. Because of this gap in regulatory
authority, FDA may not perform appropriate oversight until it is too late [12].
In 2004, Senator Dick Durbin
(D-IL) introduced legislation that would have required any product grown in a
food crop to receive pre-market approval, whether or not it was intended to be
eaten. Thus, before any pharmaceutical was produced in a food crop, FDA’s
Center for Food Safety and Applied Nutrition would conduct a food-safety
analysis to ensure that accidental human exposure to the drug through the food
supply will not cause health risks [13].
In many countries of the
world there are various reference standards on GMOs; such regulations have the
purpose of ensuring the greatest possible safety, both in environmental level
and at the level of human health and animals. At international level, the
relevant legislation is the so-called Cartagena Protocol.
As for the European
continent, the texts governing the matter GMOs are as follows:
- Regulation (EC) 1829/2003 on GM food & feed
- Directive 2001/18/EC on deliberate release into
the environment
- Commission Implementing Regulation (EU)
503/2013 on applications for authorisation of genetically modified food
and feed in accordance with Regulation (EC) 1829/2003 Directive (EU)
2015/412 amending Directive 2001/18/EC as regards the possibility for the
Member States to restrict or prohibit the cultivation of GMOs in their
territory
VIETNAM AND GM CROPS
Returning again to
the largest factory Monsato and her capacity to produce herbicides that can
also kill people. The herbicide who us use is so powerful that the US military
uses it as a defoliant in its war in Vietnam, where he conceived the insane
idea that destroying all the leaves of the trees of North and Central Vietnam
will be able to flush out the Vietcong. Instead they come to Saigon, and
they'll run away the American ambassador from the embassy roof, with the Stars
and Stripes rolled up under his arm, as he gets up on a helicopter that will
bring him back away, forever. Monsanto [14], during all that disastrous war,
the first that the Americans lost in their history, the army has sold the
infamous "Agent Orange", a mixture of 245T Monsanto and 24D of its
rival Dow Chemical, its ally for patriotic destruction of forests in Vietnam.
Scientists and the public, in addition to the mass desertions of young
Americans do suspend, in 1971, shedding the agent orange, of which there are
the effects of dioxins on the environment. It is carcinogenic, has caused
immune damage and reproduction that have not finished doing evil to the
Vietnamese. The Vietnamese government has never officially stated its stance on
the grievous actions of Monsanto and other military contractors for the U.S.,
focusing instead on reparations for victims of Agent Orange. As one
of the makers of Agent Orange, Monsanto claims they were just following
the recipe for the formula as directed by the U.S. government.
Furthermore, dioxin, found in Agent Orange, is one of the most
dangerous chemicals ever made by man. Babies are still being born today
with horrific birth defects-decades after Agent Orange was sprayed so
haphazardly across Vietnam. Nearly 4.8 million Vietnamese people have been
exposed, causing 400,000 deaths and a grab bag of health issues that would make
a haunted house seem cheery. An estimated 650,000 victims are suffering from
chronic illnesses linked to Agent Orange in Vietnam, alone. Fifty-five years
after rendering almost an entire country cancerous, chemical companies like
Monsanto are welcomed with open arms into Vietnam. It boggles the mind.
CONCLUSION
Genetically modified
foods have the potential to be many different things but their use and support
vary throughout Britain and the rest of the world. One of the most important
reasons to think about genetically modified foods is that their production and
consumption can affect you-the consumer.
By becoming informed and
educated, you can consider all of the different aspects of this issue, which
will allow you to make the best political and personal choices regarding the
role that genetically modified foods will play in your life. Given that the
biotechnology industry is a booming one with enormous annual profits, qualified
biotechnology workers are important to ensuring that the industry continues to
flourish. You can work in areas such as health care, food production and
genetic modification or you may even choose to work in areas that involve an
environmental focus.
Whether you want to work in
the development of genetically modified seeds or you are more keen to work in
the laboratory testing and safety aspects of genetically modified products,
there is an area in biotechnology that might complement your unique skills,
interests and abilities.
Your best approach is to speak to an academic advisor at your school or a local university about how to obtain a career in biotechnology. A typical day in the field of biotechnology can vary a great deal, depending on what subfield you have chosen for your career and employment. Those who work in the laboratory will likely work with a wide range of apparatus. Techniques may include DNA separation or DNA analysis and similar biological techniques.
You may also have a role in the maintenance of organisms used for genetic engineering purposes.
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