Download Human Genome Project Genetic Engineering

Genetic Engineering
Topic 8.7
Specification
• 20 Describe how drugs can be produced using
genetically modified organisms (plants and
animals and micro organisms).
• 21 Discuss the risks and benefits associated
with the use of genetically modified organisms.
Genetic modification
Define the following terms • Vector
• Plasmid
• Transgenic organism (GMO)
• Recombinant DNA
• Restriction enzymes
• Micro-propagation
• Marker gene
• Artificial selection
Transgenic bacteria
Uses of genetically modified bacteria
• Producing insulin (first commercially available
GM product 1982)
• Enzymes for washing powders
• Human growth hormone
• Clotting factors
• Human vaccines eg. hepatitis B.
• Cleaning up mercury contamination
Genetic modification in a bacteria.
• How is the desired gene
isolated?
• Describe the process
using the terms from
previous slide.
• Give some uses of
transgenic bacteria.
In cheese production, what
are the advantages of
producing chymosin from a
GMO rather than calves’
stomachs?
Transgenic Plants
Genetic modification in a plant
– What is artificial selection?
– What are the disadvantages of this process in developing
new varieties of crop plants?
– The previous slide showed a bacteria being used to transfer
a gene into a plant. What are the two other methods of
transferring the desired gene into plants?
– Why is a marker gene sometimes used when genetically
modifying crops?
– Activity 8.21 Genetic Modification - on SNAB
– 8.21a Genetic modification in plants
– Which steps in the above activity involve micropropagation?
Uses of genetically modified plants
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Resistance to weedkillers
Resistance to frost or heat or drought
Increase vitamin A content in rice
Nitrogen fixation
Resistance to pests
GM Technology Risks vs Benefits
Benefits and potential benefits
Potential risks claimed
Could help to feed the developing world e.g.
drought/disease/pest resistant crops, crops
which produce higher yield
Will not be able to feed the world- main
problem with lack of food is food
distribution not production
GM crops are more cost-effective, have a
higher yield
Could damage organic farmers because GM
crops could crossbreed with organic crops
Could benefit human health eg.
Crops which produce proteins needed to
treat CF
Rice with additional vitamin A
May have unpredictable health risks eg.
Transfer of antibiotic resistance genes to
microbes (from marker genes).
Formation of harmful products by new
genes - hard to extract and purify desired
protein alone.
Transfer of viruses from animals to humans.
Pharma crops could crossbreed with
conventional crops.
Cancers?
Benefits and potential benefits
Potential risks claimed
Could reduce pesticide and herbicide use
because of pest resistant GM crops
Could increase herbicide and pesticide
use because of “superweeds” produced
when herbicide resistant GM crops cross
with weeds
Could help preserve natural habitats e.g.
Less pesticides and herbicides are used.
Higher yield crops mean less land is
needed for agriculture.
Could reduce biodiversity. GM crops are
genetically similar to each other and
could outcompete other plants.
Mainly benefits big biotech companies.
They have the patent for the technology,
genes, crops they develop
Ethical conflicts about control of food
production
Biotech companies have the control as
they have the patent
Many GM crops are infertile so farmers
are dependent on Biotech companies
Methods used to transfer genes to
animals
Microinjection of the gene into
a nucleus of a fertilised egg
(approximately 1% success
rate)
OR
Retroviruses transfer the gene
into the fertilised egg nucleus.
The egg is then put into a
surrogate mother.
Tracey the Sheep
• Made milk with the protein AAT
• AAT inhibits elastase
• Elastase can cause lung damage (emphysema)
and liver damage (cirrhosis)
Uses of GM animals
• Mosquitos which cannot reproduce
• Salmon which grow faster
• Cows that fart less
Pharming
• Goats that produce drugs in their milk
• Eggs with β interferon used to treat MS
• Eggs with monoclonal antibody used to treat
malignant melinoma
Genetically modified animals
• Compare this process with gene therapy (AS
topic 2)
• How does it differ from somatic gene therapy?
• Method for somatic gene therapy (SGT) has to be
repeated
• In SGT only specific somatic cells are modified
• In SGT the foreign gene cannot be passed onto future
generations
Genetically modified animals
• Q8.59
– The DNA is in the nucleus surround by a nuclear envelope. It is harder
to incorporate foreign DNA into there.
• Q8.60
– AAT inhibits elastase released by neutrophils when there is an
infection
– CF patients have a lot of lung infections
– Extra AAT could reduce the inflammatory responce and lung damage
• Q8.61
– Clinical trial phase I, II and III
• Q8.62
– Short lifecyle so can be bred quickly, cheap and easy to keep, small
spaces, cheap food