Chapter 7 Animal Biotechnology

Animals in Research Figure 7.2a

Animals in Research B1 B2 B3 B4

Animals in Research Animation of Drug Development Process

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 Assign animal webquest

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

Clones Cloning Creating Dolly Limits to Cloning: The donor cell must come from a living organism An organism is also shaped by its environment The success rate for cloning is very low Clones may be old before their time The future of cloning: preservation of endangered animals, studying the effect of drugs etc on duplicates, improve agricultural production Start with Embryo Twinning (splitting embryos in half)

Transgenic Animals Retrovirus-mediated transgenesis Pronuclear microinjection Embronyic stem cell method Sperm-mediated transfer

Transgenic Animals Improving Agricultural Products with Transgenics Faster growth rates or leaner growth patterns (improve the product), more product Increase nutritional content-lactoferrin Turning the animals into efficient grazers Transfer antimicrobial genes to farm animals

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

Figure 7.11

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 anti-mouse antibody (HAMA) response 1980’s concept of the magic bullet

Figure 7.12