Transcript Chapter 7: Animal Biotechnology

Chapter 7
Animal Biotechnology
Animals in Research
Animals in Research
B1
B2
B3
B4
Animals in Research
 FDA Oversight of Drug Development Process
• Pre-Clinical Research and Development
Animation: Drug Development Process
Animals in Research
FDA Oversight of Drug Development Process
• Pre-Clinical Animal Studies
Animals in Research
 Animal Models
• Mice
• Rats
• Zebrafish (3 month generation time,
200 progeny, complete embryogenesis
in 120 hrs)
• Dogs (lungs and cardiovascular
system)
• Cats
• Pigs (PPL Therapeutics- delete a gene
which causes hyperacute rejection of
pig-to-human organ transplantation)
• Primates (HIV and AIDs research,
geriatric research)
Animals in Research
Alternatives to Animal Models
• Cell culture devices
• Researchers use cell cultures and computer-generated
models whenever possible, but this doesn’t work for looking
at an organ or entire animal
Animals in Research
Regulation of Animal Research
• The “Three Rs”
• Reduce the number of higher species (cats, dogs,
primates) used
• Replace animals with alternative models whenever
possible
• Refine tests and experiments to ensure the most
humane conditions possible
Animals in Research
Veterinary Medicine as Clinical Trials
• Treatments for humans may also be useful for
treatments with animals (e.g. the BRCA1 gene found
in 65% of human breast tumors is similar to the
BRCA1 gene in dogs)
• Hyperthermia + radiation = more effective at killing
tumors
• Stimulation of cytokines for curing skin cancers
Animals in Research
Bioengineering Mosquitoes to Prevent Malaria
• Cloned in a gene that prevents the parasite from
traversing the midgut; blocking the continuation of its
life cycle
• Developed an antibody that prevents the parasite
from entering the mosquito’s salivary gland
Cloning
A genetically identical
copy of a cell or
whole organism
Cloning
Embryogenesis – the process by which the
embryo forms and develops
• Zygote – fertilized egg
• Blastocyst – early stage embryo prior to
implantation
Cloning Methods
Embryo Twinning
Embryo Twinning Animation
Cloning Methods
Somatic Cell Nuclear Transfer
Cloning Methods
A look at Dolly the Sheep
Cloning Methods
Somatic Cell Nuclear Transfer
SCNT Animation
Cloning Methods
Click and Clone a Mouse
Limits to Cloning
Decrease Genetic Diversity
Limits to Cloning
Epigenetic Effects
Limits to Cloning
Efficiency and Cost Effectiveness
Limits to Cloning
Abnormal Development
Limits to Cloning
Premature Aging
Telomerase Animation
The Future of Cloning
Increase in genetic gain
The Future of Cloning
Consistent Quality
The Future of Cloning
Endangered Species
Transgenic Animals
Transgenic Animal – genome has
been changed to carry genes from a
different species
Transgenic Techniques
Embryonic Stem Cell Method
Transgenic Techniques
Pronuclear Injection
Animation of Pronuclear Injection
Transgenic Techniques
Making clones of a transgenic animal
Animation: Using
SCNT to make
transgenic goat
Transgenic Applications
Increased Production Efficiency:
Transgenic Growth Hormones
Transgenic Applications
Improved Food Safety and Quality:
longer shelf life
Transgenic Applications
Improved Food Safety and Quality:
lactose intolerance
Transgenic Applications
Increase Nutritional Content:
Lactoferrin
Transgenic Applications
Increased Production Efficiency:
boost lactational performance
Transgenic Applications
Disease Resistant Animals less susceptible
to mastitis
Transgenic Applications
Disease Resistant Animals less susceptible
to mad cow disease
Transgenic Applications
Decreased Environmental Impact
Transgenic Animals
Transgenic Animals as Bioreactors
• Biosteel otherwise known as spider silk, cloned into
goat milk (“silkmilk” goats)
• Goats reproduce faster than cows and are cheaper than
cows
• Hens also make good bioreactors in that they are cheap
and a lot of eggs are produced at one time
Transgenic Animals
 Knock-outs: A Special Case of
Transgenesis
• A specific gene is disrupted or
removed such that it is not expressed
• Procedure: DNA is modified, it is
added to embryonic stem cells,
where it undergoes homologous
recombination. The modified ES cells
are then introduced into normal
embryo. The embryo is implanted in
an incubator mother. The offspring is
a chimera. It may take several
generations of crossbreeding are
required to produce animals that are
complete knock-outs.
• Breast cancer mouse
Producing Human Antibodies in
Animals
Production of Monoclonal
antibodies (Mabs)
•
•
Used to treat cancer, heart
disease, and transplant
rejection
HUMANIZED monoclonal
antibodies were developed
to prevent the human antimouse antibody (HAMA)
response