Negative genetic engineering - pingu2006

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Dec 14, 2012 (4 years and 10 months ago)

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BY: CHRISTINE JOY CASTILLO

SEM SEGUI

MICHELLE SANTOS
I.
Nature
Genetic engineering is the alteration
of genetic material by direct
intervention in genetic processes
with the purpose of producing new
substances or improving functions of
existing organisms.
II. The History of Genetic Engineering
Genetic engineering owes its existence
to the developments in molecular
genetics,
virology
, and
cytology
that
culminated in the determination of the
structure of DNA by James Watson and
Francis Crick
in 1953.
Building on research involving
bacteriophages (a
bacterial virus
),
Joshua Lederberg, a
geneticist
at the
University of Wisconsin, found that
bacteria can transfer genetic
information through plasmids, small
mobile pieces of DNA that exist
independent of the
chromosomes
.
In the 1950s, Lederberg pioneered the
earliest techniques in genetic
engineering, shuffling genetic material
between bacterial cells. After the
identification of restriction enzymes
capable of "cutting" DNA in specific
locations in 1968, scientists were able
to insert foreign DNA directly into
bacterial cells.
The discovery that the foreign DNA
would naturally bond with the host
DNA, made it possible to
splice

together genes from multiple
organisms, the technique used in
recombinant DNA engineering.
Although highly complicated, rDNA
engineering can be simply explained:
genetic material from the
donor
source
is isolated and "cut" using a restriction
enzyme and then
recombined
or
"pasted" into the genetic material of the
receiver.
By 1971, advanced
transplantation

techniques had been developed and
rDNA techniques using the restriction
enzyme EcoRi were operable the
following year, leading to the first
experiments in genetic engineering.
III. OTHER TITLES
Genetic engineering,
recombinant DNA
technology,
genetic modification/manipulation
(GM) and gene splicing are terms
that apply to the direct
manipulation of an
organism
's
genes
.
[1]
IV. TERMINOLOGIES
A. GENES-
the basic unit of
heredity
in
a living
organism
. Genes hold the
information to build and maintain
their
cells
and pass genetic
traits
to
offspring. In general terms, a gene is a
segment of
nucleic acid
that, taken as a
whole, specifies a trait.
B. BREEDING-
producing of offspring,
usually animals or plants
C. MOLECULAR CLONING-
procedure
of isolating a defined DNA sequence
and obtaining multiple copies of it
in vivo
.
Cloning is frequently employed to
amplify DNA fragments containing
genes
, but it can be used to amplify
any DNA sequence such as
promoters
,
non-coding sequences, chemically
synthesised
oligonucleotides
and
randomly fragmented DNA.
Cloning is utilized in a wide array of
biological experiments and
technological applications such as
large scale protein production.
D. TRANSFORMATION-
the genetic
alteration of a cell resulting from the
introduction of foreign DNA.
E. GENETICALLY MODIFIED
ORGANISMS-
is an
organism
whose
genetic
material has been altered using
genetic engineering
techniques. These
techniques, generally known as
recombinant DNA
technology, use DNA
molecules
from different sources,
which are combined into one molecule
to create a new set of
genes
. This DNA
is then transferred into an organism,
giving it modified or novel genes.
F. GENETICS-
The branch of
biology that deals with heredity,
especially the mechanisms of
hereditary transmission and the
variation of inherited
characteristics among similar or
related organisms.
V. BODY
A.
Principles of Genetic Engineering
Just as DNA is at the core of studies in
genetics,
recombinant DNA
(
rDNA
)—
that is, DNA that has been genetically
altered through a process known as
gene splicing
—is the focal point of
genetic engineering.
DNA also can be cut into shorter
fragments through the use of restriction
enzymes.
In gene
splicing
, a DNA strand is cut in
half
lengthwise
and joined with a
strand from another organism or
perhaps even another species.
(An enzyme is a type of protein that
speeds up chemical reactions.) The ends
of these fragments have an
affinity
for
complementary
ends on other DNA
fragments and will seek those out in the
target DNA.
By looking at the size of the fragment
created by a restriction enzyme,
investigators can determine whether the
gene has the proper genetic code. This
technique has been used to analyze
genetic structures in
fetal
cells and to
diagnose certain blood disorders, such
as
sickle cell anemia
.
B. Gene Transfer
Suppose that a particular base-pair
sequence carries the instruction "make
insulin"; if a way could be found to insert
that base sequence into the DNA of
bacteria, for example, those bacteria
would be capable of manufacturing
insulin
.
This, in turn, would greatly improve
the lives of people with type 1 diabetes,
who depend on insulin shots to aid
their bodies in processing blood sugar.
(See Non-infectious Diseases for more
about diabetes.)
Although the concept of gene transfer is
relatively simple, its execution presents
considerable technical obstacles. The
first person to
surmount
these obstacles
was the American biochemist Paul Berg
(1926-), often referred to as the "father
of genetic engineering."
In 1973 Berg developed a method for
joining the DNA from two different
organisms, a monkey virus known as
SV40
and a virus called
lambda phage.

Although the accomplishment was
clearly a breakthrough, Berg's method
was difficult.
Then, later that year, the American
biochemists Stanley Cohen (1922-) at
Stanford University, and Herbert Boyer
(1936-) at the University of California
at San Francisco discovered an enzyme
that greatly increased the efficiency of
the Berg procedure.
The gene-transfer technique developed
by Berg, Boyer, and Cohen formed the
basis for much of the ensuing progress
in genetic engineering.
C. Applications
The first genetically engineered medicine
was synthetic human
insulin
, approved by
the
United States

Food and Drug Administration
in 1982.
Another early application of genetic
engineering was to create human growth
hormone as replacement for a drug that
was previously extracted from human
cadavers
In 1987 the FDA approved the first
genetically engineered
vaccine
for
humans, for
hepatitis B
. Since these
early uses of the technology in
medicine, the use of GM has gradually
expanded to supply a number of other
drugs and vaccines.
One of the best known applications of
genetic engineering is the creation of
genetically modified organisms

(GMOs) such as foods and vegetables
that resist pest and bacteria infection
and have longer freshness than
otherwise.
D. TYPES
1.
Negative genetic
engineering
When treating problems that arise
from
genetic disorder
, one solution
is
gene therapy
, also known as
negative genetic engineering.
A genetic disorder is a condition caused
by the genetic code of the individual,
such as
spina bifida
or
autism
.
[2]
When
this happens, genes may be expressed
in unfavorable ways or not at all, and
this generally leads to further
complications.
The idea of gene therapy is that a non-
pathogenic

virus
or other delivery
system can be used to insert a piece of
DNA--a good copy of the gene--into
cells of the living individual. The
modified cells would divide as normal
and each division would produce cells
that express the desired trait.
The result would be that he/she would
then have the ability to express the trait
that was previously absent at least
partially. This form of genetic
engineering could help alleviate many
problems, such as
diabetes
,
cystic fibrosis
, or other
genetic diseaseAs
.
2. Positive genetic engineering
The potential of genetic engineering to
cure medical conditions opens the
question of exactly what such a
condition is. Some view aging and death
as medical conditions and therefore
potential targets for engineering
solutions.
They see human genetic engineering
potentially as a key tool in this
(see
life extension
)
. The difference between
cure and enhancement from this
perspective is merely one of degree.
Theoretically genetic engineering could
be used to drastically change people's
genomes, which could enable people to
regrow limbs and other organs, perhaps
even extremely complex ones such as
the spine.
It could also be used to make people
stronger, faster, smarter, or to increase
the capacity of the lungs, among other
things. If a gene exists in nature, it
could be brought over to a human cell.
In this view, there is no qualitative
difference (only a quantitative one)
between, for instance, a genetic
intervention to cure
muscular dystrophy
,
and a genetic intervention to improve
muscle function even when those
muscles are functioning at or around
the human average (since there is also
an average muscle function for those
with a particular type of dystrophy,
which the treatment would improve
upon).
E. Religious objections
The Roman Catholic Church, under
the papacy of Benedict XVI, has
condemned some particular cases of
genetic engineering in the
instruction
Dignitas Personae
,
stating that in those situations it
contradicts the fundamental truth of
equality between all human beings
.
[3]
F. Ethics
The genetic engineering of humans has
raised many controversial
ethical
issues.
With the release of the 1997 cult film
Gattaca
, human genetic engineering has
been widely debated.
While negative genetic engineering
(gene therapy) does indeed raise a
debate, the use of genetic
engineering for human
enhancement arouses the strongest
feelings on both sides