2. Genetics 8: Production and Regulation of Genetically Engineered Organisms

3. Breakthroughs in Science  Recombinant DNA has led to so many possibilities but also many controversies.  Gene Therapy: the correct form of a defective gene is inserted into a patient’s genome.  Making new animals (ie the zebra fish have recombinant DNA that causes a fluorescent colour. Long term safety issues are unknown)  Designer children?  How far should we go?  Who makes these decisions?

4. Genetic Engineering  The alteration of the genetic material of an organism  Precise and specific  We can introduce a mutation to a gene  We can introduce foreign DNA into a genome from another organism’s genome that results in a transgenic organism  Transgenic bacteria, plants and animals are commonly refereed to as genetically modified organisms (GMOs)

5. Transgenic Bacteria in Pharmaceuticals  By putting a gene into a bacterial cell and making the bacteria create that particular enzyme or protein for us, we then purify it and use it for medicine. (Insulin)  Other examples:  Human growth hormone  Tissue plasminogen activator (treats blood clots)  Erythropoietin (stimulates red blood cell production)  Hepatitis B vaccine

6. Transgenic Bacteria and Bioremediation  Bioremediation is when we use microorganisms to clean up the environment because they can convert toxic chemicals into non-toxic products.  Bacteria that can naturally break down crude oils was genetically modified so it can do so more effectively.  Others include:  bacteria that can break down pesticides in water systems  Remove sulfur from coal to make cleaner emissions when coal is burned.

8. Transgenic Plants  Started thousands of years ago by meticulously cross-breeding and artificial selection.  Examples of transgenic crops: soybeans, corn, canola, tomatoes, potatoes.  Most modifications have to do with increased tolerance to herbicides, greater resistance to disease which lead to increased crop yield, reduced harvesting costs, reduced pesticide use and slower spoilage.  Two ways to make transgenic plants: biolistic and Ti plasmid methods.

9. Making Transgenic Plants: Biolistic Method  Striking plant cells with tiny particles of gold or platinum that are coated with DNA  Sometimes called the gene-gun method because they are shot at high speeds to allow the DNA to penetrate the cell wall.

10. Making Transgenic Plants: Ti plasmid Method  Ti plasmid stands for tumour-inducing plasmid that is a naturally occurring plasmid in the bacterium Agrobacterium tumefaciens that causes growths on plants. Part of the Ti plasmid, called the T-DNA integrates into the plant genome and causes uncontrolled cell growth.  Researches have altered the T-DNA of the Ti plasmid so that it no longer causes the tumour formation, but still allows for the gene to integrate into the DNA of the plant cell.

11. Controversies…  Are GMOs safe for human consumption?  7-10 years of health and safety research first  Will GMOs affect the environment?  Vertical gene transfer: transfer of a gene into the genome of a wild organism.  Harm that a GMO with insecticidal protection may have. (ie Bt corn reduces the affect that bacteria might have on corn, but it may hurt the monarch butterfly populations)  Insects may become resistant to these changes over time anyway.

12. Transgenic Animals  A foreign gene is inserted into the genome of an animal oocyte and is then fertilized.  Used to produce fish, pigs, cows, rabbits and sheep.  Example: pigs engineered so they can break down phosphates in their food better leading to better absorption, less excreted which then reduces the phosphate contamination of water sources.

13. Gene Pharming  Transgenic animals that produce human therapeutic proteins.  Hormones from sheep  Plasminogen activator Factor IX that helps with blood clotting  Alpha anti-trypsin for emphysema

14. Mammalian Cloning  Dolly the sheep was the first  Since then we have cloned cows, pigs, mice, dogs and cats.

16. Questions:  Page 311 #5 - 9, 12