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Genetic Engineering
Bio.3.3.2 Summarize how transgenic organisms are engineered to
benefit society
Bio.3.3.3 Evaluate some of the ethical issues surrounding the use of DNA
technology (including cloning, genetically modified organisms, stem cell
research, and Human Genome Project).
Human Genome Project
• The goals of the Human Genome Project
were to determine the nucleotide sequence
of the entire human genome and map the
location of every gene on each chromosome.
• This information will advance the diagnosis,
treatment, and prevention of human genetic
disorders.
• The Human Genome Project included
sequencing the genes of many model species
to provide insights into gene function.
Human Genome Project
• We learned there are far fewer proteinencoding human genes than once
believed but far more proteins because
of the complex way they are encoded.
• Bioinformatics uses computers to
catalog and analyze genomes.
• Proteomics studies the identities,
structures, interactions, and
abundances of an organism’s proteins.
Recombinant DNA
• Researchers use
restriction enzymes to
insert DNA fragments
into vectors (often a
virus).
• The resulting DNA
from two different
organisms is called
recombinant DNA.
Recombinant DNA
• The human genes for insulin and blood clotting factors
has been placed in bacterial plasmids.
• This allows the bacteria to produce human insulin and
human clotting factors.
• People in need of insulin, diabetics, or clotting factors,
hemophiliacs, can receive these products much
cheaper than in the past with no threat of being
exposed to blood borne diseases.
Recombinant DNA
• Organisms created through recombinant DNA
technologies are included in the broad classification of
genetically modified organisms.
• Golden rice
• Rice that contains carrot genes so the rice includes the
precursor of vitamin A.
• A lack of vitamin A results in the death of 1-2 million children
annually and blindness in half a million more children.
Gene Therapy
• Gene therapy refers to treating genetic disorders by
correcting a defect in a gene or by providing a normal
form of a gene.
• A normal piece of DNA can be made in lab and inserted
into a vector (something that will deliver the normal DNA
to the person’s cells)
• Many times, a virus shell is used as the vector
• The virus “infects” the
person’s cells, injecting the
corrected DNA.
• Cell now uses corrected DNA
to carry out its normal
functions.
• Cystic fibrosis is treated this
way.
Cloning
• In cloning by nuclear transfer, a nucleus from a body
cell of one individual is introduced into an egg cell
(without its nucleus) from another individual.
• An organism identical to the nucleus donor results.
Cloning
• First mammal cloned was a sheep. The clone was
named Dolly.
• Dolly had an abnormally short lifespan.
• Her telomeres were too short so her cells couldn’t go
through mitosis as many times as usual.
Ethical Issues
• Some people fear that the release of genetically
modified organisms would pose an environmental
risk.
• Breeding with non-transgenic organisms could spread the
engineered genes
• Who owns or controls these genes?
• In some cases the plants are engineered to not produce
pollen or seeds so the engineered genes don’t spread but
that means the farmers can’t collect seeds and replant.
They have to purchase them every year.
Ethical Issues
• Allergens
• GMOs could contain genes for something that a person is
allergic to but they aren’t expecting that allergen to be in
that food.
• Where is the line between medical treatment and
enhancement?
• What if we eliminate a gene that causes a disease but
also has a benefit (maybe one we don’t know about)?
Ethical Issues
• Should people be allowed to select their child’s traits?
• Who should have access to your genetic information?
• Should your employer know you have a higher chance of a
heart attack than others?
• Should your insurance company be allowed to deny you
coverage if you have a heart attack because you had a
pre-existing condition thanks to your genes showing an
increased risk?
• Should parents be required to do genetic engineering
on a child with a genetic disease?