Genetically Modified Organisms Biomedical Technology I 3.03

GMO’s: Also known as Transgenic Organisms Are species that carry one or more genes from another species. These have continued to improve since the 1970’s

Advantages: 1. Important tools for Biomedical Research 2. May prove to be an economical way to produce many human substances such as hormones that are otherwise difficult and expensive to obtain. 3.May be the future answer to the shortage of organ transplants 4. Setting the stage for gene therapy in humans

Biotechnology Is a collection of scientific techniques that use living cells and molecules to make products and solve problems. By using natural processes of living organisms, biotechnology allows us to enhance our health, our environment and our food supply.

History of Biotechnology For thousands of years, we have conducted selective breeding to improve our livestock, controlled plant pollination to produce better crops and used microorganisms to bake bread, brew beer and make cheese. Today, we use some of these same organisms to produce human hormones (like insulin for diabetes) and improve our livestock and crops. This is accomplished by transferring specific genes from one species to another.

GMO’s/Transgenic Organisms The first transgenic organism were bacteria They reproduce quickly by mitosis (cell division) and are easy to grow in the lab. They are still used today by pharmaceutical companies to provide patients with insulin, human growth hormone and interferons (substances with antiviral and anticancer abilities)

Advantages of Transgenic Animals Models for human disease A way to improve the quality and health of livestock Another method to produce pharmaceuticals “Pharming” A source of organs for humans”Xenografts” A model for gene therapy in humans (Substituting the normal gene for hemoglobin to replace the one that causes sickle cell anemia)

First Transgenic Animal The first transgenic animal was created in 1975. Scientist 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 researcher produced the first transgenic mouse strain, whose offspring did contain the implanted transgene.

Harvard Mouse In the 1980’s, scientist placed an oncogene into to a mouse and created the Harvard Mouse. This mouse carries the human oncogene that predisposes mice to cancer. This made history, because it was the first time a U.S. patent was granted for a genetically engineered animal. These mice remain commercially available today.

How to produce a Transgenic Animal: Steps: Example using Mice 1. Construct the transgene, which is the DNA to be transferred. 2. The female are given hormones so they superovulate (Produce a large number of eggs) 3. Then they are mated 4. Hours later, single-cell embryos are removed from the females

Steps con’t: 5. Using a microscope and a microinjector, scientists inject each embryo with copies of the transgene. 6. These eggs are then transferred to surrogate mothers of the same strain that have been treated with hormones so the eggs can implant and grow.

Outcome? Scientists can determine if the mice in the litter have the gene by analyzing a small piece of each mouse’s tail when it is 8-10 days old, using a technique called Polymerise Chain Reaction. The success rate is low.

Care of Transgenic Animals Most do not require special care. Some have disorders that makes them susceptible to disease, in these situations, special attention is needed. Only the healthiest animals are used Researchers are constantly testing and observing their animals for any unexpected effects of the genes they introduc.

Government’s Role: The NIH uses transgenic animals in biomedical research The USDA uses them in livestock and veterinary research. A number of laws, regulations and guidelines govern the use and care of research animals. Researchers must apply for a patent from the US Patent and Trademark office before creating a transgenic organism.

Ethical Considerations: Some people are concerned about the possibility that animals and plants with altered genetic characteristics could threaten our environment, our health and our food supply. Animal welfare groups feel that genetic manipulation will lead to increased animal suffering. Some believe people are “playing God”

Ethical Considerations: Some are concerned that scientist will try and use this on humans This concerned came when “Dolly” the cloned sheep came about in 1997.

Proponents of Transgenic Organisms: State that benefits must be considered: 1. Transgenic animal models provide a powerful new way to study numerous diseases. 2. Vital substances needed by the human body may soon be available at a reasonable cost 3. Sufficient numbers of human organs are not available for transplantation and transgenic animals may provide a new source of organs.

The Future of Transgenic Organisms: Scientist still have a long way to go to perfect this However, the use of transgenic models has become an established part of biomedical research Bio companies are already producing transgenic pigs whose offspring may alleviate the shortage of organs for human transplantation.