Genetic engineering


Genetic Engineering (sometime abbreviated "genegineering"), Genetic
Modification (GM), and Gene Splicing (once in widespread use but now
deprecated) describe the process of manipulating genes in an animal or
plant, outside of the organism's normal reproductive process.

It often involves the isolation, manipulation and reintroduction of DNA into
model organisms, usually to express a protein. The aim is to produce new
species, increase the yield of an existing species, or to design new
organisms. Examples are the production of human insulin through the use of
modified bacteria and the production of new types of mice like the OncoMouse
(cancer mouse) through genetic redesign.

Since a protein is specified by a DNA segment or gene, future copies of that
protein can be modified by changing the gene's underlying DNA. One way to do
this is to isolate the DNA, cut it, and splice in a different DNA segment.
Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in
physiology or medicine for their isolation of restriction endonucleases,
which are able to cut DNA at specific sites. Together with ligase, which can
join together fragments of DNA, restriction enzymes formed the initial basis
of recombinant DNA technology.

Naming

Genetic modification or genetic manipulation are neutral and possibly more
technically correct terms for what is controversially claimed (by its
advocates) to be genetic "engineering". While those who engage in the active
manipulation of plant and animal genomes often claim to be in control of the
outputs of the process, in fact, the operations of genes in combination with
cell biochemistry are rather poorly understood so sometimes lead to
unexpected side effects.

Defenders of the term genetic engineering argue that all engineering and
commercial production processes have unforeseen side effects and quality
control problems, and that the fact that the output of their work is a
living organism, does not necessarily make it impossible to apply the
principles of engineering. It is politics, they argue, not economics or
science, that causes their work to be closely investigated, and for
different standards to apply to it than to other fields of engineering.
These 'engineers', however, do not object to the term 'genetic modification'
as applied to what they do - only as it is used to deny them the status of
professionals serving society in an ethical manner, which is one implication
of the term "engineer".

Reluctance to recognize this field as "engineering" has become popular in
the anti-globalization movement and safe trade movement, and is also widely
held by most Green parties, and the major parties of France and Germany,
which have resisted any agricultural policy favoring genetically modified
food. These groups tend to resist the label 'engineer' as applied to such
genetic modification most strongly.

As use of genetic techniques spreads into medicine and reproduction, the
controversy is spreading with it, along with the labels applied, some of
which, e.g. "frankenfood", appear to be prophetic, as genetic techniques
have indeed come to be used on humans.

Applications

The best known applications of genetic engineering are genetically modified
organisms (GMOs).

There are potentially momentous biotechnology applications of GM, for
example oral vaccines produced naturally in fruit at very low cost. This
represents, however, a spread of genetic modification to medical purposes
and opens an ethical door to other uses of the technology to directly modify
human genomes.

These effects are often not traceable back to causes in the genome, but
rather in the environment or interaction of proteins. The means by which
'genes' (in fact DNA strands that are assumed to have discrete effects) are
detected and inserted are themselves so inexact as to defy characterization
as 'science' - including such means as coating gold BBs with DNA to be
inserted and literally firing it at strands of target DNA, which is
guaranteed to cause insertions in at least some random locations.

Similar objections apply to protein engineering and molecular engineering.
However, a single protein or a molecule is easier to examine for 'quality
control' than a complete genome, and there are more limited claims made for
the reliability of proteins and molecules, than for the genomes of whole
organisms. While protein and molecule engineers acknowledge the requirement
to test their products in a wide variety of environments to determine if
they pose dangers to life, the default position of most 'genetic engineers'
is that they do not need to do so, since the outputs of their work are
'substantially the same as' the original organism which was produced by the
original genome(s).

Recent mammal cloning results have shown this to be a questionable claim, at
best. Some argue that human cloning has been hyped, and people may unwisely
be attempting it, in part due to public perceptions that genomes can
actually be 'engineered' as opposed to 'modified' - or that genetic
problems, e.g. cystic fibrosis, can be 'cured in the womb' by the
application of such 'genetic engineering' techniques. An extreme ambition of
some groups is human augmentation via genetics, eventually by artificial
intelligence or molecular engineering. See also: transhumanism.

Genetic Engineering and Research

Although a there has been a tremendous revolution in the biological sciences
in the past twenty years, there is still a great deal that remains to be
discovered. The completion of the sequencing of the human genome, as well as
the genomes of most agriculturally and scientifically important plants and
animals, have increased the possibilities of genetic research immeasurably.
Expedient and inexpensive access to comprehensive genetic data has become a
reality, with billions of sequenced nucleotides already online and
annotated. Now that the rapid sequencing of arbitrarily large genomes has
become a simple, if not trivial affair, a much greater challenge will be
elucidating function of the extraordinarily complex web of interacting
proteins, dubbed the proteome, that constitutes and powers all living
things. Genetic engineering has become the gold standard in protein
research, and major research process has been made using a wide variety of
techniques, including

- loss of function, or knockout experiments, in which an organism is
engineered to lack one or more genes. This allows the experimenter to
analyze the defects caused by this mutation, and can be considerably useful
in unearthing the function of a gene. It is used especially frequently in
developmental biology. A knockout experiment involves the creation and
manipulation of a DNA construct in vitro, which, in a simple knockout,
consists of a copy of the desired gene which has been slightly altered such
as to cripple its function. The construct is then taken up by embryonic stem
cells, where the engineered copy of the gene replaces the organism's own
gene. These stem cells are injected into blastocysts, which are implanted
into surrogate mothers. Another method, useful in organisms such as
drosophila, is to induce mutations in a large population and then screen the
progeny for the desired mutation. A similar process can be used in both
plants and prokaryotes.

- gain of function experiments, the logical counterpart of knockouts. These
are sometimes performed in conjunction with knockout experiments to more
finely establish the function of the desired gene. The process is much the
same as that in knockout engineering, except that the construct is designed
to increase the function of the gene, usually by providing extra copies of
the gene or attracting more frequent transcription.

- 'tracking' experiments, which seek to gain information about the
localization and interaction of the desired protein. One way to do this is
to replace the wild-type gene with a 'fusion' gene, which is a juxtaposition
of the wild-type gene with a reporting element such as green fluorescent
protein that will allow easy visualization of the product. While this is a
useful technique, the manipulation can destroy the function of the gene,
creating secondary effects and possibly calling into question the results of
the experiment. More sophisticated techniques are now in development that
can track protein products without mitigating their function, such as the
addition of small sequences which will serve as binding motifs to monoclonal
antibodies.

Ethics

Genetic engineering proponents argue that the technology is harmless and
necessary for food production to continue to match population growth.
However others oppose this view, taking the stance that proponents are
almost always in a position to gain from the technology. For example,
American maize farmers and seed producers have benefited financially from
the development of varieties that are toxic to plant eating insects (see bt
corn). However, the genes for this resistance have rapidly left the American
fields, and are now present in multiple strains of wild and domestic maize.
This amounts to a contamination of the very gene pool from which the
domestic maize was derived.

Anti-genetic-engineering groups propose that genetic releases such as this
represent the opening of a Pandora's Box which may ultimately accelerate the
collapse of the modern non-sustainable system of agriculture, decreasing
rather than increasing the food supply. They say that with current
recombinant technology there is no way to ensure that genetically modified
organisms remain under control, and the use of this technology outside of
secure laboratory environments carries grave risks for the future.

Proponents of current genetic techniques as applied to food plants cite the
benefits that the technology can have, for example, in the harsh
agricultural conditions of third world countries. They say that with
modifications, existing crops would be able to thrive under the relatively
hostile conditions providing much needed food to their people. While
submitting that precautions should be made to ensure that any modified crops
are contained, they say that their genetically engineered crops are not
significantly different from those modified by nature, and by extension are
not dangerous to other crops. There is a surprisingly high range of gene
transfer occurring naturally - for example haemoglobin genes from the animal
kingdom are known to have been transferred into a plant, probably through a
viral intermediate ??details. There is gene transfer between unicellular
eukaryotes and prokaryotes. There have been no known genetic catastrophes as
a result of this.

Economic and Political Effects

The increasing use of GM in major crops has caused a power shift in
agriculture. Biotechnology companies have gained far greater control over
the production chain than was true of the seed companies that predated them.

Genetic Engineering in Fiction

In Marvel Comics, the 31st century adventurers called the Guardians of the
Galaxy are genegineered residents of Mercury, Jupiter, and Pluto.

In the Star Trek universe, the Breen, Species 8472, the Xindi, and the
Federation use technology with organic components.

In the Star Wars universe, the Yuuzhan Vong are a race who exclusively use
organic technology and regard mechanical technology as heresy. Everything
from starships to communications devices to weapons are bred and grown to
suit their needs.

The film Gattaca had themes of genetic engineering.