Creating solutions for health and nutrition
Recombinant DNA technology is another major DNA-based
tool that has gained popular attention in the past decade. This technology
allows scientists to find individual genes, cut them out, and insert
them into the genome of another organism. Recombinant DNA technology has applications in health and nutrition. In medicine, it is used
to create pharmaceutical products such as human insulin. In agriculture,
it is used to impart favorable characteristics to plant to increase
their yield and improve nutritional content. Recombinant
DNA technology requires the use of molecular scissors called restriction
enzymes, which cut DNA at specific sequences. The cut-out gene is
then inserted into a circular piece of bacterial DNA called a plasmid.
The plasmid is then re-introduced into a bacterial cell. When the
bacteria multiply, the plasmids multiplies as well, creating many
copies of the gene. Since bacteria multiply very quickly, large
numbers of the gene can be produced in the laboratory for further
analysis and application.
Producing Human Insulin
Diabetics are unable to produce satisfactory amounts of insulin,
which facilitates the processing of sugars from food into energy
that the body can use. In the past, diabetics needed to take insulin
purified from pigs and cows to fulfill their insulin requirement.
However, non-human insulin causes allergic reactions in many diabetics.
Recombinant DNA technology provided a way for scientists to produce
human insulin in the laboratory.
The
gene for human insulin is isolated from human cells and inserted
into plasmids. These plasmids are then introduced into bacterial
cells, which manufacture the insulin protein based on the human
code. The purified product is identical in nature to human insulin
and does not cause any allergies.
In addition to bacteria, other biotechnologists use
yeast in recombinant DNA technology to make human insulin. Yeast
can perform more of the complicated cellular processes that occur
in human cells, making it a more useful organism for producing human
substances.
For more information on using the use of DNA technology
in producing insulin, please visit DNA
Interactive: Manipulation.
Producing Genetically Modified Foods
A widely debated application of recombinant DNA technology is in
the production of genetically modified foods. Genes can be derived
from plants or even other organisms to give plants characteristics
that are beneficial to both producers and consumers of agricultural
products:
- Delayed fruit ripening for longer shelf life during transportation
- Resistance to insects and plant viruses
- Enhanced flavor and nutritional content
- Edible vaccines to prevent widespread diseases in developing
countries
The technology behind genetic modification of foods
is similar to the one used to produce human insulin, with an additional
step. After the bacteria multiply the gene of interest, the gene
is then introduced into plant cells so that the plant will manufacture
the gene product: whether it is an insecticide, vaccine, or other
plant substance.
Because agriculture is conducted on such a large
scale, the use of genetically modified plants poses ecological implications
that must be considered carefully. For a review of these issues
and for more information about the use of recombinant DNA technology
in agriculture, please visit the Genetically
Engineered Organisms: Public Issues Education Project.
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