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Genetic Engineering (3500 words)
Biology
Also called: biotechnology, gene splicing, recombinant DNA technology
Anatomy or system impacted: All
Specialties and relevant fields: Alternative medicine, biochemistry, biotechnology,
dermatology, embryology, eth ics, forensic medication, genetics, pharmacology, preventive
medicine
Definition: hereditary engineering, recombinant DNA technology and biotechnology – the
buzz terms you have heard frequently on radio or TV, or find out about in showcased articles in
newspaper s or popular publications. It is some methods which are used to attain one or
more of three goals: to show the complex procedures of exactly how genes are inherited and
expressed, to give you better understanding and effective treatment plan for different diseases,
(par ticularly genetic disorders ) and to produce financial advantages which include
improved plants and pets for farming, and efficient production of valuable
biopharmaceuticals. The characteristics of genetic engineering possess both vast promise
and pot ential hazard to human being kind. Its an understatement to state that genetic
engineering will revolutionize the medication and agriculture in the 21 st future. As this
technology unleashes its capacity to influence our daily life, it will likewise bring challenges to
our ethical system and religious opinions.
Key terms:
GENETIC ENGINEERING: the number of a wide array of strategies that alter the
genetic constitution of cells or people by selective treatment, insertion, or
modification of specific genes or gene se ts
GENE CLONING: the growth of a line of genetically identical organisms which
contain identical copies of the same gene or DNA fragments
GENE TREATMENT: the insertion of a practical gene or genes into a cell /tissue/organ to
correct a genetic abnormali ty
PCR: abbreviated from polymerase chain reaction, a n in vitro process through which specific
parts of a DNA molecule or a gene could be rapidly changed to millions or huge amounts of copies
within a short time
RECOMBINANT DNA: a hybrid DNA molecule created within the te st pipe by joining a DNA
fragment of interest with a carrier DNA
SOUTHERN BLOT: an operation that is used to move DNA from a gel to a nylon
membrane, which often enables the finding of genes that are complementary to particular
DNA sequences called pro bes
Genetic Engineering and Human Health
Soon following the book regarding the brief essay by Crick and Watson on DNA structure
(1953), research started initially to unearth the way through which DNA molecule s may be cut and
“spliced” straight back together. With all the breakthrough of th e very first limitation endonuclease by
Hamilton Smith et al. (1970), the true tale of genetic engineering started initially to unfold. The
creation of this very first engineered DNA molecule through splicing DNA fragments of two
unrelated types together had been made general public in 1972. Quickly implemented had been a complete array
of recombinant DNA particles, genetically modified germs, viruses, fungi, plants and
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animals. The debate throughout the dilemmas of “tinkering with God” heated up and public outcry
over hereditary engineering ended up being wide -sprea d. The delivery of “Dolly”, initial mammal ever
cloned from a grownup body cellular, has elevated the debate over the effect of biological
research to a new degree. Also, a number of genetically modified organisms
(GMOs) have already been commercially released s ince 1996. Today, approximately over
70per cent people foods have some components from GMOs.
Obviously, genetic engineering holds tremendous vow for medication and human
well -being. Medical applications of hereditary engineering consist of diagnosis for genetic
and other diseases; treatment for hereditary problems; regenerative medication using
pluripotent (stem) cells; production of safer and much more effective vaccines, and
pharmaceuticals; the chance of curing genetic problems through gene therapy; the l ist
goes on… because of its prospective to provide mankind unprecedented energy over life itself,
the research and application of hereditary engineering has created much debate and
controversy. Many individual diseases, particularly cystic fibrosis, Downs problem, frag ile X
syndrome, Huntington’s illness, muscular dystrophy, sickle -cell anemia, Tay -Sachs
disease, etc. are inherited. There are often no traditional treatments for these
disorders because they don’t answer antibiotics or other customary drugs. Another
area is the c ommercial manufacturing of vaccines and pharmaceuticals through genetic
engineering, which has emerged as a rapidly developing field. The possible of
embryonic stem cells to be any cell/tissue/organ under sufficient conditions holds
en ormous vow for regenerative medication.
a. Prevention of Genetic Disorders
Although prevention may be attained by avoiding these ecological facets that cause
the abnormality, t he best prevention, when feasible, should lessen the frequency
of or eliminate completely the harmful genes (mutations) from the basic populace. As
more exact tools and procedures for manipulating specific gene s are optimized, t his
will sooner or later be a real possibility. The prevention of genetic disorders at prese nt is usually
achieved by ascertaining those individuals in populace that prone to passing a
serious genetic disorder to their offspring, offering them hereditary counseling and prenatal
screening followed with the selective abortion of affected fe tuses.
Genetic counseling may be the means of communicating information gained through classic
genetic studies and modern research to those folks who are themselves at risk
or have a high likelihood of moving defect s for their offspring. During guidance,
information concerning the infection it self — its severity and prognosis, if here are
effective therap ies, as well as the risks of recurrence is generally presented. For all couples
who get the dangers unacceptably high, counseling might also in clude discussions of
contraceptive practices, use, prenatal diagnosis, possible abortion and artificial
insemination by a donor, etc. Even though the concluding decision must nevertheless rest with the
couple on their own, the significant escalation in the precision of danger assessment made
possible with hereditary technology helps it be easier for moms and dads to make well -informed
decisions.
To the se couple s whom get the burden of experiencing an affected child intolerable, prenatal
diagnosis may resolve their dilemma. Prenatal screen ing might be done for a variety
of hereditary disorders. It requires types of fetal cells or chemicals made by the fetus
through either amniocentesis or chorionic villus sampling. After sampling, several
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analyses could possibly be performed. First, bioch emical analysis is used to find out the
concentration of chemical substances into the test and therefore diagnose whether a particular
fetus is deficient or low in enzymes that facilitate specific biological responses. Next,
analysis of the chromosomes associated with feta l cells can show if all of the chromosomes are
present, and whether you will find any structural abnormalities in almost any of them. Finally,
the most reliable means is identify the defective genes through recombinant DNA
techniques. This has become feasible with the quick enhance of DNA copies through a
technique called PCR, which could create practically limitless copies of a particular gene or
DNA fragment, beginning with as little as an individual content. Routine prenatal diagnosis is
being performed to display fetus for Down syndrome, Huntington’s infection, sickle -cell
anemia and Tay -Sachs illness. Procedures are increasingly being developed for prenatal diagnosis of
more and more serious genetic disorders. Hence, a successful roadblock to your moving of
defective genes from a single g eneration to a different within the population is possible.
b. Remedy for conditions and hereditary Disorders
Genetic engineering works extremely well for direct treatments of conditions or genetic disorders
through different means, such as the production of possible vaccine s for AIDS,
treatment for different cancers, synthesis of biopharmaceuticals for many different metabolic,
growth and development conditions, etc. Generally, biosynthesis is a procedure in which gene
coding for a certain product is isolated, cloned into another or ganism (mostly bacteria),
and later expressed for the reason that organism (host). By cultivating host organism, large quantities
of the gene items could be harvested and purified. Some examples will illustrate the
useful top features of biosynthesis. Insulin is esse ntial for the treatment of insulin -dependent
diabetes, the most severe as a type of diabetes. Historically, insulin ended up being acquired from a beef
or pig pancreas. Two problems occur the old-fashioned availability of insulin. First, large
quantities of this pancreas ar e needed seriously to extract enough insulin for constant treatment
of one patient. 2nd, insulin so acquired is not chemically identical to peoples insulin,
hence some clients may produce antibodies which can seriously interfere with the
treatment. Individual insul in produced through genetic engineering is fairly effective yet
without any side -effects. It's been produced commercially and made available to
patients since 1982.
Another successful story in biosynthesis could be the manufacturing of human development hormone
(H GH), which can be used in treating children with development retardation called pituitary
dwarfism. The successful biosynthesis of HGH is important because of a few reasons. The
conventional source of HGH had been human being pituitary glands eliminated at autopsy, which only
exist in brain and liver. Each kid suffering from pituitary dwarfism needs twice -a-week
injections before the age of 20. Such cure regime requires over a thousand
pituitaries. It’s apparent that a utopsy supply could not keep up with the demand.
Furthermore, considering a small amount of virus contamination in the extracted HGH, many
children getting treatment developed virus related diseases. Other biopharmaceuticals
under development or in pre -clinical or medical trials through genetic e ngineering include
anti -cancer medications, anti -aging agents and a potential vaccine for AIDS, malaria, etc.
generally, t hree types of gene treatment exist, germ line therapy, enhancement
gene therapy and somatic gene therapy. All gene therapy trials cur rently underway or in
the pipeline are restricted to the somatic cells as goals for gene transfer. The germ line
therapy involves the introduction of novel genes into germ cells such as for instance egg/early
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embryo. Alt hough it offers the possibility correcting def ective genes once for many, germ
line gene treatment is very controversial and presently banned by numerous countries. The
enhancement gene treatment, whereby human being potential may be enhanced for some
desired faculties, raises a much better ethical dilemma. Both germ line and enhancement
gene therapy have already been banned on the basis of the unresolved ethical dilemmas surrounding them.
Somatic gene treatment is designed to introduce practical gene(s) to body cells, which
enable the body to execute normal functions hence provid ing short-term modification for
genetic abnormalities. The cloned human being gene is first transported into a viral vector,
which can be used to infect white blood cells taken from the patient. The transferred
(normal) gene will be placed into a chromosom e and becomes active. After development to
enhance their figures under sterile conditions, the cells are re -implanted to the client,
where they produce a gene product which lacking inside untreated patient, enabling the
individual to function ordinarily. S everal disorders are being addressed with this
technique, including serious combined immunodeficiency (SCID ). Individuals with
SCID haven't any practical immunity system and often die from infections that could be
minor in normal individuals. Gene therap y normally getting used or tested as remedy for
cystic fibrosis, skin cancer, breast cancer, brain cancer tumors, and AIDS. But many of
these treatments are just partially successful, yet prohibitively costly. Over a 10 —
year duration (1990 -2000), more t han 4000 individuals were treated through gene therapy.
regrettably, most of these studies were failures that resulted in a loss of confidence in gene
therapy. The main reasons behind these problems have now been caused by inefficient vector s.
in the foreseeable future, as mor age efficient vectors are engineered, gene therapy is expected become a
common technique f or treat ing many hereditary disorders.
Genetic Engineering i n Agriculture, Forensics and ecological Science
As making use of genetic engineering expands quickly, it’s hard to create an exhaustive list
of all feasible applications. But you will find about three other areas well worth noting –
forensic, environmental, and agricultural applications. Although these three areas are not
directly related to medicine, they undoubtedly have actually profound impacts on peoples fine -being.
There are wide ranging methods hereditary engineering enables you to benefit farming and
food manufacturing. First, the manufacturing of vaccines and the application of methods for
transferring genes fo r commercially crucial faculties such as for instance milk yield, butter fat and
higher proportion of slim meat will probably gain animal husbandry. As an example, the
bovine growth hormone produced through hereditary engineering has been utilized since late
1980’s to enhance m ilk manufacturing by cow. A mutant kind of the myostatin gene, nick —
named “Schwarzeneger gene” was identified and discovered to cause hefty muscling
after this gene was introduced into mouse, and soon after the Belgian Blue bull. This marks
the first faltering step toward breeding cows and meat pets with lower fat and higher
proportion of lean meat. Other samples of using genetic engineering in animal
husbandry include hormones for faster development rate in chicken, manufacturing of recombinant
human proteins inside milk of livestock, etc.
Second, hereditary engineering is expected to considerably affect the conventional
approaches of developing new strains of plants through breeding. The technology allows
transferring genes for nitrogen fixation; enhancing photosynthesis (an d therefore yield);
resistance to pests, pathogens and herbicides; and threshold to frost, drought, increased
salinity; and enhanced vitamins and minerals and customer acceptability. Genetically
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engineered tobacco plants have already been grown to produce protein pha seolin, which is
naturally synthesized by soybean alongside legume plants. The very first genetically
engineered potato ended up being authorized for human usage by US government in 1995, and
by Canada in 1996. This NewLeaf potato, produced by corporate giant Monsan to (St.
Louis, MO), carries a gene from bacterium Bacillus thuringiensis. This gene
produces a protein toxic on Colorado potato beetle, an insect which causes substantial
loss of the crop if left uncontrolled. The manufacturing of this protein by po tato plants equip
them with resistance to beetles, hence alleviates crop loss, saves expense on pesticides and
reduces the possibility of environment contamination. Antiviral genes were successfully
transferred and expressed into cotton, as well as the release of new cotton stress s with
resistance to numerous viruses is simply a matter of time. At least five transgenic corn strains
with resistance to herbicide or pathogens are developed and commercially
produced by US farmers by 2002. Some genes coding tolerance to drought, also to sub —
freezing conditions have already been cloned and moved into or among crop flowers, some
of that have currently made a good affect farming in developing countries. Initial
effort was built to replace chemical fertilizers w ith more environment friendly
biofertilizers. Secondary metabolites produced obviously by flowers have also been
purified and utilized as biopesticides. Fleetingly, we will have more grain, produce, milk and
meat that are made by animal or plants which may have b een genetically engineered one
way or another.
DNA fingerprints from samples collected during the crime scene provide strong evidence in
trials thus assist resolving many violent crimes. DNA can very quickly be separated from tissue left
at a crime scene, a splatterin g of blood, a hair sample or even epidermis left under a victim’s
fingernails. Nowadays, many different methods can be utilized routinely to determine the
probability of matching between test DNA and that of a suspect. DNA fingerprints
are also useful in paren thood disputes, settling the disputes over who has the proper to
certain home, learning the genealogy of numerous species.
The metabolism of microorganisms is modified through genetic engineering, which
enables them to absorb and degrade waste/haza rdous product from environment. The
growth price and metabolic capabilities of microorganisms offer great possibility coping
with some environmental issues. Sewage plants may use engineered germs to
degrade many organic substances into non -toxic su bstances. Microbes may be
engineered to detoxify certain toxic wastes in waste dumps or oil spill s. Numerous bacteria
can extract hefty metals (lead, copper, etc.) from their surroundings and incorporate
them into compounds being recoverable, therefore servin g to completely clean these toxic heavy metals
from environment. There are many more such applications yet to be tested and
discovered.
Perspective and Prospects
Since the finding associated with the dual -helical framework of DNA by Francis Crick and James
Watson in 1953, individual interest regarding this unique molecule has propelled the
advancement of biological sciences in an unprecedented fashion. The very first successful
experiment in genetic engineering ended up being described in 1972 when DNA fragments from two
different organisms had been accompanied together to create a biologically practical hybrid
DNA molecule. The next milestone came in 1975, when Dr. Edward Southern
introduced a technique that has many applications and proved invaluable for
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subsequent growth of genetic engine ering. This system, Southern blotting, is
used to spot a specific gene or DNA fragment from an assortment of thousands of
different genes or DNA fragments. Later on, the automatic DNA sequencers that can
rapidly turn out page sequences from DNA frag ments, the development of reverse
transcriptase and PCR further improve our capabilities in studying and manipulating
DNA particles and genes they carried.
Using these methods, the first prenatal diagnosis of a genetic illness had been made in
1976 for -tha lassemia, a genetic disorder brought on by the absence of globin genes. This
represented a monumental step of progress into the usage of hereditary tools in medical industry. It
paved just how the subsequent development in which mutations in lots of genes could be
detected in very early maternity. 3 years later on, insulin was first synthesized through
genetic engineering. In 1982, the commercial production of genetically engineered
human insulin became a real possibility. 1st complete human genetic map had been published in
1993, a nd different new techniques in DNA fingerprinting and the isolation of specific
genes were developed, studies of gene therapy also begun in 199 0, very first with SCID. Additionally,
an increasing wide range of pharmaceuticals are increasingly being produced through hereditary engineering.
Two variations associated with draft copy for the peoples genome had been posted in 2001, launching
off the genomic revolution. In 21 st century, hereditary engineering continues to offer
more advantages in medicine as well as in agriculture in many ways we have never imagined befo re.
In retrospect, hereditary engineering gift suggestions a mixed blessing of invaluable benefits and
dilemmas that science and technology have constantly offered to hu mankind. There are
those who wants to limit the uses of hereditary engineering and whom might p refer that
such technology had never ever been developed. Other people feel that the benefits far outweigh the
possible dangers and that any potential threat can be overcome through government
regulation and/or legislation. Others do not just take part s in the deba te generally speaking but are
greatly focused on some certain applications. Clearly, the power of genetic
engineering need s a new pair of choices, both ethical and economic al, by individuals,
government while the entire culture. Considerable concern ended up being expressed by both
scientists additionally the average man or woman regarding feasible biohazards from genetic engineering.
What do we do if engineered organisms prove resistant to any or all known antibiotics or carry
cancer genes which can spread through the community? Let's say a genetically
engineered plant becomes an uncontrollable super weed? Would most of these danger s
outweigh the potential advantages? Alternatively, other people argue your danger ha s been
exaggerated, and therefore usually do not desire to impose restrictions on res earch. Genetic engineering
has additionally produced legal issues concerning intellectual properties and patents for different
aspects of technology. Much controvers y is unsettled as a result of the differences in
perception of patent together with pitfall of the existin g patent law.
Even more controversial are numerous ethical problems. Possibly the most apparent ethical issue
surrounding genetic engineering is the objection to some applications which are considered
socially unwelcome and morally incorrect. Just take bovine growth hormone as an example,
some vigorously opposed its use in boosting milk production for two major causes. First,
the recombinant hormone may change the composition associated with milk. However, t his view
has been dismissed by specialists from National Institute of He alth and Food and Drug
Administration after a comprehensive study. 2nd, many dairy farmers worry that greater milk
production per cow will drive rates down even more and put some tiny farmers out
of business. Numerous aspects of the application of gene tic engineering to humans also
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present ethical challenges. For partners who both carry a defective gene and have an
appreciable possibility of having an affected kid, should they refrain entirely from having
children of the own? For genetic disorders cause d by chromosomal abnormalities, such
as Tay -Sachs illness, prenatal diagnosis can identify the problem in a fetus with great
precision. The question then becomes, if the fetus be aborted if the screening result
is positive? Should assessment tests of inf ants for genetic disorders be required? If so,
would such requirement infringe the rights associated with the person by the us government? Perhaps
the best concern of all of the could be the possibility to design or clone a human being through
genetic engineering. A few of t hese concerns are genuine and expressed with good
intentions. The debate over ethical, appropriate and social implications of genetic engineering
should help formulating and optimizing general public policy and laws and regulations concerning the technology.
Research and applications of genetic engineering should continue with caution and
humility.
-Ming Y. Zheng, Ph.D.
For more info:
Brungs, Robert S .J., and R.S.M. Postiglione, eds. The Genome: Plant, Animal, Human. St.
Louis, ITEST Faith/Science Press, 2000. An assortment o f exceptional medical, ethical,
educational and theological papers focus on the genomic revolution as well as the application of
genetic engineering to plant, animal and human.
Daniell, H., S.J. Streatfield, and K. Wycoff. Healthcare molecular farming: manufacturing of
antibodies, biopharmaceuticals and edible vaccines in plants. 2001. Trends in Plant
Sci ence 6: 219 -226. A contemporary review on the production of plant -based medicinal
products through hereditary engineering and associated biotechnology.
Dudley, William, ed. Hereditary Engineering: Opposing Viewpoints. Hillcrest,
Greenhaven Press, 1990. Present balanced and well -thought opposing views on genetic
engineering by proponents and opponents from different perspectives.
Frankel, M.S., and A. Teich, eds. The Genetic Frontier. Washington, DC, American
Association for the Advancement of Science, 1994. A wonderful assortment of essays
from numerous professionals and organizations working with the ethics, legislation and policy on genetic
engineering.
Holland, Suzanne, K. Lebacqz, and L. Zoloth, e ds. The Human Embryonic Stem Cell
Debate. Cambridge, The MIT Press, 2001. Extremely thoughtful reflections on debates
regarding stem cellular research and prospective pros and cons by some extraordinary
people from diverse disciplines.
Kilner, John F., R.D. P entz, and F.E. younger, eds. Genetic Ethics: Perform Some Ends Justify the
Genes? Grand Rapids (MI), William B. Eerdmans Publishing Co., 1997. An assembly of
experts details three dimensions for the hereditary challenge: genetic perspective, genetic
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information, and hereditary intervention. Wonderful number of useful and informative
guiding concepts on genetic engineering.
Kmiec, E.B. Gene therapy. 1999. US Researchers 87: 240 -247. Good summary on
current styles in developing and the studies of gene therapy.
Old, R.W., and S.B. Primrose. Concepts of Hereditary Manipulation: An Introduction to
Genetic Engineering. Palo Alto (CA), Blackwell Scientific, 1994. A resource book that
provides foundational knowledge in the concept and process of genetic engineering.
Tal, J. Adeno -associated virus -based vectors in gene treatment. 2000. Journal of
Biomedical Science 7: 279 -291. Good summary on gene therapy and perspective on recent
development regarding the topic.
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