Download BI0152: Genetic engineering

BI0152: Genetic
engineering
Lecture 25
December 6
Overview of the issues
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Outline-Genetic Engineering
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Pre-test
Introduction to the issues
Compare and contrast biological evolution
(via mutation, natural selection, genetic drift)
with genetic engineering
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[Pretest]
1. What does GMO stand for?
a.
b.
c.
Gene Manipulation in Organisms
Greatly Modified Organisms
Genetically Modified Organisms
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2. What is a gene?
a.
b.
c.
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A style of pants
Proteins that determine characteristics
such as blood group.
The basic unit of heredity made of DNA
(deoxyribonucleic acid)
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3. What is genetic engineering?
a.
b.
c.
Deliberate technological application of living
things for human use.
Deliberate manipulation of genetic material.
Selective breeding (also called artificial
selection)
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5. What is biotechnology?
a.
b.
c.
Living organisms (plants, animals, fungi,
bacteria) or their components are used to
make products
Transplanting genes or organs from one
organism to another
Cloning organisms
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6. Altering, exchanging or transferring genes is
not a natural phenomenon (does not occur in
nature without human intervention).
a.
b.
c.
True
False
I don’t know
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7. Genetic engineering is bad.
a.
b.
c.
No, but it may produce dangerous results.
Yes, because it is not a natural process.
Undecided
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8. Genetic engineering will only serve
industry and the “developed” areas of the
globe.
1.
2.
3.
True
False
I don’t know
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The issues
“A scientific revolution is in progress that
promises to alter all prior rules on how
humankind interacts with the biotic world.”
John C. Avise,
The Hope, Hype, and Reality of Genetic
Engineering, 2004 p. vii
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Dr. Frankenstein or Dr. Doolittle?
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Uncontrollable monsters that turn against
their makers or
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Obedient companions faithfully carrying out
human-assigned roles
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What is biotechnology?
= Living organisms (plants, animals, fungi,
bacteria) or their components used to make
products
What five things beginning with "F" do we get
from plants, animals, or microbes ?
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What we get from plants, animals,
microbes (starting with “F”)
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Food
Fiber
Fuel
Feedstocks
“F”(Ph)armaceuticals
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biotechnology “detector”
Classic examples where we use biotechnology:
„ Bakery
„ Brewery
„ Cheese factory
[all use microbes for fermentation]
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Biotechnology & Genetic Engineering
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Biotechnology is the broad term used to
describe situations where living organisms or
their components are used to make products.
Under this broad area
falls the topic of genetic
engineering.
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Genetic Engineering
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Over the last 50 years we have learned how
to:
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directly alter the DNA of a cell
Intentionally exchange genes between organisms
(same species & different species)
Transfer one gene at a time rather than thousands
Generate novel combinations of genes
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Genetic Engineering differs from
conventional breeding
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a specific gene can be selected & transferred
we don’t need to wait for a mutation to happen
naturally to a particular gene- saves time and
reduces dependence on ‘chance’
Genes between species can be selected and
transferred
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What is a GMO?
genetically modified organism
or a
„ genetically engineered organism
or
„ transgenic organism:
a gene from one organism is
deliberately incorporated into the
genome of another
can be a virus, bacterium, plant,
animal, fungus etc whose DNA has
been altered for a particular purpose
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Nature vs. ‘Frankenfoods’
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Human beings have been eating genetically
modified foods since the dawn of agriculture.
When the term Biotechnology became tied to this
process, people expressed mixed opinions about
the ethics of this process.
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“Natural” versus manipulated
Genetic engineering (GE) harnesses a natural
process to generate specific changes.
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Bacteria
„
Commonly ‘swap’ genetic material-between
same and DIFFERENT groups!
→ potential for antibiotic resistance and
pathogenicity (ability to cause disease)
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Mixed plant & bacterial genes
[common, not rare]
e.g., Arabidopsis-mustard family
Small genome ~ 100,000 base pairs of DNA
„ [Natural] Genome evolution involved large
scale duplication
„ 18% of Arabidopsis protein-coding genes
are bacterial in origin (arising naturally over
time-not through human intervention)
(Prof. B. Saville)
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Viruses
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Insert into genomes
Can carry other genes from organism to
organism
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What can GEs do?
Transgenic plants
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Herbicide tolerant: herbicides can be used on them to kill
weeds with out harming the crop
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Insect resistant: produce substances that repel or kill
insect pests
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Virus resistance: contain genes from a virus that confer
resistance to the same virus
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Climate & soil tolerant : capable of typically adverse
conditions including high salt, low moisture, low pH,
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Transgenic animals
‰ help researchers diagnose and treat
human diseases
‰ produce pharmaceuticals in their milk
‰ Can be used for xenotransplantation
‰ Have a higher production of meat, milk,
and eggs
‰ More resistant to disease, and more hardy
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What is the risk/reward of GE?
Some GE ‘agendas’ are small gambles with
huge potential payoffs for society
Some are LARGE gambles with minimal
payoffs for society (though large financial
payoffs for the company) Avise, 2004
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Access Excellence @ National Health Museum copyright 1999 [cited December 6,
2006]
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What do GMOs offer?
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GMOs are being used to produce a variety of products which
may improve standards of living, and provide major health
benefits
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Medicine
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Pharmaceutical production
Gene therapy
Disease diagnosis and treatment
Food production
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Higher yields
Higher nutritional value (vitamins, iron, protein)
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Genetically Modified Pigs
Xenotransplantation: The transplantation of tissues
or organs from one species into another species,
typically from non-human mammals to humans
„ Pigs are being genetically modified with human
genes so their organs can be used in humans
„ This minimizes the need for
use of immunosuppressive
drugs to overcome rejection
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GE Applications with bacteria
Pharmaceutical production e.g., insulin, human
growth factor
Biomining - Using bacteria to extract minerals from
ores.
Cleaning Up Wastes - Using bacteria to digest
pollutants.
Future Fuel - bacteria-based energy
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Improving health in developing nations
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Crops with improved nutritional quality and health
benefits
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Clean and safe methods for the production of edible
vaccines
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Golden rice-vitamin A & iron
Bananas
Disease and drought resistant crops
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The introduction of high yield, drought tolerant, early ripening
maize in Central and West Africa
An improved quality and quantity of meat, milk and live stock
production
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Concerns about using GMOs to increase
human health
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Transferring Allergens
‰ A substance, most often eaten or inhaled, that is
recognized by the immune system and causes an
allergic reaction
‰ If genes being transferred are novel to the food
supply it will be difficult to assess if they are
potential allergens
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Xenotransplantation
‰ The fear of endogenous pig viruses
crossing species to infect humans due to
xenotransplantation
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The Environment
In what ways will the environment be
effected by GMOs?
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The promising prospects of GMOs
Crops are being grown in areas where farming was
once limited
„ By increasing crop yields, GMOs reduce the
constant need to clear more land for growing food
„ Conservation of soil, water and energy
„ Remediation:
E.g., transgenic cotton weed trees may be able to
remediate soil and water contaminated with
mercuric compounds.
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Equipping crops with insecticidal genes could
allow for safer pesticides
An overall reduction of chemically intensive
farming
An avenue for technological development
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Provides the opportunity for a renewable resource
to be developed based on living organisms rather
than fossil fuels
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The concerning aspects of GMOs
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The transfer of herbicide resistance into non
target plants could result in super weeds
Spread resistance among pests
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The increased use of pesticides would be the
inevitable result
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Potential for serious ecological risks
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The rate of gene flow between crop plants
and their wild relatives may be higher than
thought.
Genes for virus resistance can mix with
genes from other viruses that naturally infect
the plant
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This could create new combinations which may be
deadlier than the ones before
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There is a fundamental concern about the
protection of biodiversity for the
equilibrium of the ecosystem
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Overview Summary
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Genetic engineering has the POTENTIAL to be a
blessing to:
‰ To produce high nutrient, affordable food & to
ensure farmers receive enough profit from their
labor to keep them in business
‰ To be used for medical solutions and
bioremediation
GE used cautiously, may also be as safe as
naturally occurring gene swapping
Dr. Frankenstein or Doolittle???
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