Transcript Transgenic Animals

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Warm-up
L.95 What is the difference
between:
1. a mastectomy and a mammography?
2. Living will and durable power of attorney?
3. CT scan and MRI?
4. Preciptin test and Kastle Meyer test?
5. CDC and WHO?
6. Allocation and procurement?
7. In situ cancer and invasive cancer?
8. Radiographer and radiologist?
9. Applied research and clinical research?
10.Random Question: If a patient weighs 165
pounds, how many grams does he weigh?
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Transgenic Animals
Introduction
• Over the past few decades, human and
nonhuman animals have benefited from
biotechnology.
• For thousands of year, we have conducted
selective breeding to improve our livestock.
• 50 years after the structure of DNA was first
discovered, scientists use some of those same
microorganisms to produce human hormones
and improve our livestock and crops.
What are transgenic organisms?
• Organisms which contain other
species’ genes within their
chromosomes.
• In order to produce a transgenic
animal, scientists inject a transgene
into a single cell organism.
Interesting Fact:
• The first transgenic organisms were
bacteria because they are the simplest
forms of life.
• They are still used by pharmaceutical
companies today to produce a variety of
human proteins such as insulin and
human growth hormones.
Use of transgenic techniques in
animals:
• Models of human disease
• A way to improve the quality and health of
livestock
• Another method to produce
pharmaceuticals
• A source of organs for humans
• A model for gene therapy in humans (e.g.,
substituting the normal gene for
hemoglobin to replace the one that causes
sickle cell anemia.
First Transgenic Animal
• 1975 – implanted an ape gene into a
mouse.
• The mouse produced the ape protein but
did not pass the gene onto offspring.
• Two years later, the same researchers
produced the first transgenic mouse strain,
whose offspring did contain the implanted
transgene.
Success and growing
• Transgenic animal production increased
rapidly in the 1980s as scientists improved
genetic engineering techniques and
identified and purified more genes.
The approval process:
• Biomedical researchers must go through
an approval process to create a transgenic
animal by applying for a patent from the
US Patent and Trademark Office.
Benefits of Transgenic
Animals
Animal models
• They reproduce quickly
• They are small animals and therefore
easily housed.
• Their genetic makeup is better understood
than other mammals
• Their lifespan is 2-3 years, allowing
researchers to follow disease processes
from infancy to old age over a relatively
short time.
Animal models cont.
• Hundreds of mouse strains already exist
with spontaneous genetic mutations (flaws
within their genes) that resemble human
diseases (diabetes, dwarfism).
• By producing genetically engineered
mutations, scientists have more control
over what genes they are studying and
don’t have to wait for spontaneous
mutations to appear.
Pharmaceutical production
• It is reproducible
• The amount of drug produced is limited
only by the number of successful
transgenic animals produced and its
offspring.
• Maintaining the animal is more
economical, compared to the amount of
drug produced, than growing cells in tissue
culture.
Organ donors
• Successful because physicians have an
arsenal immosuppressive drugs.
• Alternative: using xenografts’ (pigs)
• Improving the success rate because of
body’s want to reject these organs.
• Carry few infectious agents
• Reproduce quickly and have large litters
• Less social opposition to using pigs than
to using non-human primates
Livestock improvement
• Transgenic technology could produce
animals that are larger, leaner, more
efficient at using feed, or more resistant to
disease.
• Safety of meat or dairy products – people
strongly oppose the products of transgenic
animals
Care of Transgenic Animals
• Do not require special care
• Sometimes have a disorder that makes
them susceptible to disease.
• Scientists use only the healthiest animals
and do their best to keep the animals
healthy.
Against Transgenics?
• There are many ethical considerations to
the opposition of transgenic animals:
– Animal welfare
– “Playing God”
– Use the techniques in humans
– Threaten our environment, health, food supply
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Processing
L.95 Processing
• Now that you know what transgenic
animals are, draw a caricature that
represents what a transgenic is.
• Make it colorful and creative.