More biomedical research challenges Transgenic animals

What is Biotechnology? Early beginnings Biotechnology – collection of scientific techniques that use living cells and molecules to make products and solve problems

Transgenic Organisms Organisms that contain another species’ genes within their chromosomes

Transgenic animals Historically – used in selective breeding of livestock, controlled plant pollination, and microorganisms to bake bread, brew beer and make cheese This is accomplished by transferring specific genes from one species to another First transgenic organisms were bacteria

How are transgenic animals created? Involves merging genetic engineering with cell biology and reproduction. Step 1: construct the transgene, which is the DNA to be transferred. Step 2: The transgene is introduced into a single-cell embryo stage of an organism. Step 3: The embryo is transferred to a surrogate mother of the same strain that has been treated with hormones so that the egg can implant and grow.

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What are the benefits of using transgenic animals? Animal models Pharmaceutical production May fill the need for organ donations Livestock improvement

What animals are transgenic techniques used on? Mice are most commonly used because: The reproduce quickly They are small and easily housed Their genetic makeup is easily understood compared to other animals They have a short life span; researchers can follow a disease process in a timely manner.

Are transgenic techniques used on other animal models? Species include sheep, goats, cows, chickens, pigs, mice, rabbits, rats, chickens and fish Success rate is low (10%-30%) in mice and decreases in mammals

Do transgenic animals require specialized care? Most do not require special care Some may be more susceptible to disease

Pharmaceutical production Also called “pharming” Scientists inject the gene into large farm animals because it has many advantages: it is reproducible the amount of drug produced is only limited by the number of successful transgenic animals produced and their offspring it is a better return on investment than growing the cells in culture (in a lab)

Organ donors Using organs from other species (called xenografts) for human transplants Pigs are of interest because they carry few viruses that can be transferred to humans, they reproduce quickly and have large litters, and there is less social opposition to using pigs than to other nonhuman primates.

Livestock improvement Transgenic technology can produce animals that are larger, leaner, use feed more efficiently and are more resistant to disease. The process has proven to be very expensive to date. Public concern over meeting the meat and dairy safety standards in the products from these animals has not been fully satisfied.

Is there any government oversight? U.S. Patent and Trademark Office issues patents for transgenic animals NIH Guidelines for Research Involving Recombinant DNA Molecules (the only government policy addressing genetically altered animals in research)

What are there ethical concerns? People opposed to transgenic animal research believe: It increases animal suffering. That animals with altered genetic characteristics could threaten our environment, our health and food supply. That Scientists are “playing God” That scientist will use these techniques on humans. That there are risks associated with genetic manipulation. Since the success rate of introducing transgenes into embryos is low, it should not be pursued.

Opposing view: People in favor of transgenic animal research believe: That transgenic animal models provide a powerful new way to study diseases. That it may be a way to make vital substances (needed by the human body) available at a reasonable cost. That their use may provide a new source of organs for those in need of organ transplants. That transgenic techniques may one day provide treatments human diseases such as sickle cell & cancer.

Transgenic Models are currently an established part of BM research impacting the fields of: Immunology Pharmacology Neurology Cancer research

Future of transgenic animals Current research limited to transferring a small amount of genes at a time Much work remains to be done to fine-tune techniques so we can isolate complex traits which are influenced by many genes. Scientists are looking for more precise ways to insert the transgene into the recipient's chromosome Possible effects of foreign DNA remains a concern

From GSK Gene-based biomedical research offers one of the best hopes yet for curing the major diseases which still afflict mankind. The use of transgenic animals is central to realizing that hope and offers the potential for the use of fewer animals in more targeted experiments. We must be clear. There are only two alternatives to using animals. One is to use humans in basic research; the other is to delay or even give up the search for desperately needed new treatments and cures. The appropriate use of transgenic animals is a positive development with potential for significant medical benefits. The challenge is for governments, industry and society to ensure that transgenic research continues to be sensitively carried out for proper medical ends in a suitably balanced regulatory environment.

Transgenic animals in research… What is your opinion based on the facts?