Genetic Engineering
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All that we are is the result of what we have thought
Buddha
For what shall it profit a man, if he shall gain the whole world and lose his own soul?
The Bible
Introduction
While plant biotechnology has been used for centuries to enhance plants, microorganisms and animals for food, only recently has it allowed for the
transfer of genes from one organism to another. Yet there is now a
widespread controversy over the harmful and beneficial effects of genetic
engineering to which, at this time, there seems to be no concrete solution.
The ideas below are expected to bring in a bit of clearance into the topic.
Here I’m going to reveal some facts concerning genetic engineering, specially the technology, its weak and strong points (if any). Probably the
information brought is a bit too prejudiced, for I’m certainly not in favor
of making jokes with nature, but I really tried to find some good things
about GE.
What is genetic engineering?
Genetic engineering is a laboratory technique used by scientists to change
the DNA of living organisms.
DNA is the blueprint for the individuality of an organism. The organism
relies upon the information stored in its DNA for the management of every
biochemical process. The life, growth and unique features of the organism
depend on its DNA. The segments of DNA which have been associated with
specific features or functions of an organism are called genes.
Molecular biologists have discovered many enzymes which change the
structure of DNA in living organisms. Some of these enzymes can cut and
join strands of DNA. Using such enzymes, scientists learned to cut specific
genes from DNA and to build customized DNA using these genes. They also
learned about vectors, strands of DNA such as viruses, which can infect a
cell and insert themselves into its DNA.
With this knowledge, scientists started to build vectors which incorporated
genes of their choosing and used the new vectors to insert these genes into
the DNA of living organisms. Genetic engineers believe they can improve the
foods we eat by doing this. For example, tomatoes are sensitive to frost.
This shortens their growing season. Fish, on the other hand, survive in
very cold water. Scientists identified a particular gene which enables a
flounder to resist cold and used the technology of genetic engineering to
insert this 'anti-freeze' gene into a tomato. This makes it possible to
extend the growing season of the tomato.
At first glance, this might look exciting to some people. Deeper
consideration reveals serious dangers.
Techniques
There are 4 types of genetic engineering which consist of recombinant engineering, microinjection, electro and chemical poration, and also bioballistics.
r-DNA technology
The first of the 4, recombinant engineering, is also known as r-DNA technology. This technology relies on biological vectors such as plasmids and viruses to carry foreign genes into cells. The plasmids are small circular pieces of genetic material found in bacteria that can cross species boundaries. These circular pieces can be broken, which results with an addition of a new genetic material to the broken plasmids. The plasmids, now joined with the new genetic material, can move across microbial cell boundaries and place the new genetic material next to the bacterium's own genes. After this takes place, the bacteria will then take up the gene and will begin to produce the protein for which the gene codes. In this technique, the viruses also act as vectors. They are infectious particles that contain genetic material to which a new gene can be added. Viruses carry the new gene into a recipient cell driving the process of infecting that cell. However, the viruses can be disabled so that when it carries a new gene into a cell, it cannot make the cell reproduce or make copies of the virus.
Microinjection
The next type of genetic engineering is referred to as microinjection. This technique does not rely on biological vectors, as does r-DNA. It is somewhat of a simple process. It is the injecting of genetic material containing the new gene into the recipient cell. Where the cell is large enough, injection can be done with a fine-tipped glass needle. The injected genes find the host cell genes and incorporate themselves among them.
Electro and chemical poration
This technique is a direct gene transfer involving creating pores or holes in the cell membrane to allow entry of the new genes. If it is done by bathing cells in solutions of special chemicals, then it is referred to as chemical poration. However, if it goes through subjecting cells to a weak electric current, it is called electroporation.
Bio ballistics
This last technique is a projectile method using metal slivers to deliver the genetic material to the interior of the cell. These small slivers, which must be smaller than the diameter of the target cell, are coated with genetic material. The coated slivers are propelled into the cells using a shotgun. After this has been done, a perforated metal plate stops the shell cartridge but still allows the slivers to pass through and into living cells on the other side. Once inside, the genetic material is transported to the nucleus where it is incorporated among host cells.
The history of GE
The concept was first introduced by an Australian monk named Gregor Mendel
in the 19th century. His many experiments cemented a foundation for future
scientists and for the founding concepts in the study of genetics.
Throughout Mendel's life, he was a victim of criticism and ridicule by his
fellow monks for his "foolish" experiments. It took 35 years until he was
recognized for his experiments and known for the selective breeding
process. Mendel's discoveries made scientists wonder how information was
transferred from parent to offspring and whether the information could be
captured and/or manipulated.
James D. Watson and Francis H. C. Crick were curious scientists who later
became known as the founding fathers of genetic engineering.
Watson and Crick wanted to determine how genetic blueprints are determined
and they also proposed that DNA structures are genetic messengers or that
chemical compounds of proteins and amino acids all come together as a way
to rule out characteristics and traits. These 2 scientists produced a code
of DNA and thus answered the question of how characteristics are
determined. They also established that DNA are the building blocks of all
organisms.
Selective breeding and genetic engineering
Selective breeding and genetic engineering are "both used for the
improvement of human society." However, selective breeding is a much longer
and more expensive process than genetic engineering. It takes genetic
engineering only one generation of offspring to see and study improvement
as opposed to selective breeding where many generations are necessary.
Therefore, it costs more to observe many generations.
Selective breeding is known as the natural way to engineer genes while
genetic engineering is more advanced, technical, scientific, complex and is
inevitable in out future.
What are the dangers?
Many previous technologies have proved to have adverse effects unexpected
by their developers. DDT, for example, turned out to accumulate in fish and
thin the shells of fish-eating birds like eagles and ospreys. And
chlorofluorocarbons turned out to float into the upper atmosphere and
destroy ozone, a chemical that shields the earth from dangerous radiation.
What harmful effects might turn out to be associated with the use or
release of genetically engineered organisms?
This is not an easy question. Being able to answer it depends on
understanding complex biological and ecological systems. So far, scientists
know of no generic harms associated with genetically engineered organisms.
For example, it is not true that all genetically engineered foods are toxic
or that all released engineered organisms are likely to proliferate in the
environment. But specific engineered organisms may be harmful by virtue of
the novel gene combinations they possess. This means that the risks of
genetically engineered organisms must be assessed case by case and that
these risks can differ greatly from one gene-organism combination to
another.
So far, scientists have identified a number of ways in which genetically
engineered organisms could potentially adversely impact both human health
and the environment. Once the potential harms are identified, the question
becomes how likely are they to occur. The answer to this question falls
into the arena of risk assessment.
In addition to posing risks of harm that we can envision and attempt to
assess, genetic engineering may also pose risks that we simply do not know
enough to identify. The recognition of this possibility does not by itself
justify stopping the technology, but does put a substantial burden on those
who wish to go forward to demonstrate benefits.
Fundamental Weaknesses of the Concept
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