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| Fig. 2 - Bollworm Larva; Peggy Greb |
Biotechnology has
come a long way since the seeds of favourable plants were cultivated and
alcohol was produced from the wild yeasts growing on fruit.
Today, the concept of
biotechnology also covers a range of sophisticated processes that raise
ethical, social, environmental, moral and legal issues. Some of these involve
the effects on human embryos, experimental animals, the environment, farmers,
consumers and various religious groups.
Stem Cell Research and Human Embryos
Much of the
controversy around the use of human embryonic stem cells arises from current ‘therapeutic
cloning’ research. This process involves the creation of a human embryo using
the techniques of somatic cell nuclear transfer (SCNT). In this procedure, the
nucleus from an adult body cell is removed and inserted into an enucleated egg
cell (see fig. 1). The resulting diploid cell is then cultivated in the
laboratory until it reaches the blastocyst stage (a mass of around 200 cells).
Stem cells are then
extracted from the blastocyst and stimulated to grow into the specific cells
required in patients suffering from diseases such as diabetes, Parkinson’s
disease and Alzheimer’s disease. Other areas of research include the use of
these stem cells to grow replacement bone, cartilage, muscle and neural tissue
in humans.
Some human life
groups regard the blastocysts produced for therapeutic cloning as human beings
that consequently should not be used for experimental purposes. In 2006, George
Bush vetoed a bill to extend the funding for stem cell research in the U.S.,
with the result that only cells derived from existing embryos could be used.
President Obama reversed this decision in 2009 to include newer stem cell lines
but funding for cells created in the future is limited to those produced privately
or at a state level.
Alternatives to the
use of embryonic stem cells are currently being investigated, and include the
potential use of adult stem cells from bone marrow and umbilical cords to
replace skin, nerve or muscle cells and the reprogramming of adult skin cells
to emulate stem cells by introducing artificial viruses. This research has the
approval of many Church groups as it does not involve the destruction of
embryos.
Genetically Modified Foods
Genetically modified
food is produced from organisms containing genes from another species. Examples
include Bt cotton , which contains a bacterial gene for bollworm resistance
(see fig. 2) , 'Roundup Ready' GM Canola, which is resistant to herbicides and
virus-resistant sweet potatoes. Other examples include Golden rice, high in
beta carotene because it contains genes from daffodils and bacteria and ‘Sumo
Salmon’, which contains a gene for bovine growth hormone. The obvious benefits
of GM foods include improved yield and nutrition, resistance to pesticides,
herbicides and weather extremes, longer shelf life, and increased food security
in poorer nations.
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| Fig. 1 - Somatic Cell nuclear Transfer |
In addition, many GM
crops are sterile, which means that farmers need to keep buying the seeds from
the affluent multinationals that produce them. General issues of access also
apply here; third world countries, for instance, may have less chance of
obtaining the much promoted food security offered by these crops if large
companies have a monopoly over them.
Moreover, since some
GM companies have prevented peer review of their research, some doubt
inevitably remains over the safety of GM foods. Some of these concerns include
the risk of contamination by antibiotic resistant marker genes, which could
enter the human digestive system, and allergic reactions to unforeseen proteins
and toxins produced by introduced genes.
Environmental
concerns include horizontal gene transfer, which could, for instance, confer
herbicide resistance to weeds, and a general reduction in biodiversity.
Genetically modified animals or plants may also overrun native species if
released into the wild and harmless insect species may be affected by
insecticide resistant plants such as Bt cotton. In addition, religious groups
and vegetarians may object to eating plants containing animal genes.
Monoclonal Antibodies and the Treatment of Animals
The production of monoclonal
antibodies (Mabs) is a recent development in the field of medical
biotechnology. These antibodies are produced by injecting an antigen into mice,
which stimulates the production of B lymphocytes specific to the antigen in
question. The B lymphocytes are then removed from the mouse and fused to
cancerous cells (forming hybridoma’ cells) so that they will multiply rapidly
and produce large amounts of the desired antibody. Mabs can be used to treat
diseases such as breast cancer and leukaemia or to diagnose the presence of
cancers or hormones in humans.
Grave concerns,
however, have been raised regarding the treatment of mice in this procedure.
This includes the fact that the spleen of the mouse is often removed to obtain
the required B lymphocytes. Moreover, the use of adjuvants (chemicals which
over-stimulate the immune system) has been shown to cause great distress in the
animals, as has the ascites method for propagating hybridoma cells. In this
method, used when in vitro methods are not feasible, the hybridoma cells are
re-injected into the abdominal cavity of the mouse, cultivated and then
removed.
Other areas of
biotechnology raise similar issues.The benefits we are gaining or may gain in
the future from these techniques should be balanced against such concerns.
References
Australian Government
NHMRC,2008, 'Guidelines for Monoclonal Antibody Production', nhmrc.gov.au
Human Genome Program,
2008 ‘Genetically Modified Foods and Organisms’,ornl.gov
Monsanto v.
Schmeiser, 2010, percyschmeiser.com
National Institutes
of Health, 2010, 'Stem Cell Information', nih.gov
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