Recombinant DNA & Genetically Modified Organisms (GMOs)

1. Recombinant DNA&Genetically Modified Organisms (GMOs) Bio-engineered (GM) Food BrochureCAPT Embedded Task

2. Variation Through Technology—Recombinant DNA (ch 10 sec 2) • Scientists have learned how to transfer a gene artificially from a donor organism to a bacterium • Recombinant DNA: the DNA of the bacterium that has been altered by insertion of a foreign gene • The bacterium transcribes & translates the foreign gene to produce the protein coded for by the foreign gene

3. How is genetic engineering accomplished??? • Plasmids: small, circular pieces of “extra” DNA found in bacteria • structures with which foreign DNA is recombined • Techniques involves making many recombined plasmids & putting them together w/ bacteria that will absorb them • Bacteria then begin to produce large quantities of the protein (coded for by the foreign DNA) • Ex. Insulin

4. Obtaining the Foreign Gene • Synthesize the desired gene • Find a cell that specializes in producing the desired protein • b/c contains many mRNA molecules that carry the genetic code for the protein • Identify & isolate the mRNA molecules • Produce a single-stranded DNA molecule (using an enzyme obtained from a virus & the mRNA in a process that is the reverse of transcription) • Single-stranded DNA is converted to double-strand using an enzyme normally used for replication • This double-stranded DNA is the desired gene. • 1000s of copies of the gene must be made using cloning

5. Inserting the Foreign Gene • Before DNA can be inserted into plasmid, the plasmid must 1st be broken open at a specific point & changed from circular form to linear form • Point where nucleotides of the plasmid’s DNA will match the nucleotides of the foreign DNA • Accomplished using enzymes that are know to break DNA only at specific points • Used on both the plasmid & foreign DNA • The 2 segments of DNA w/ matching ends then join & the plasmid regains circular shape

8. Inserting the Foreign Gene • Recombinant DNA then mixed w/ bacteria in a liquid medium • Some of the bacteria take up the plasmids (& if recombinant DNA has located properly) & begin to produce desired protein, which they secrete into the medium • Protein extracted from medium, purified, & put to use.

10. Applying Recombinant DNA Techniques • Recent advances have enabled geneticists to develop modified techniques that can be applied to: • Genes being inserted into eukaryotic cells • Genes being inserted into whole organisms • Genes inserted into isolated cells grown in a culture medium • Human gene for protein that dissolves blood clots inserted into fertilized goat eggs • Recombined fertilized eggs implanted into female goats for development • 2 of the eggs picked up the foreign gene & developed into baby goats (1 male & 1 female) ~These animals are called “transgenic” b/c they contain genetic material from 2 species *The transgenic female goat secretes the clot-dissolving protein in her milk

11. Applying Recombinant DNA Techniques • Transgenic plants produced to resist disease & spoilage, a hardier, are more nutritious ( more food, less $$$) • Special method needed due to tough cell wall • Foreign genes can be inserted into these cells by one of several methods: • Foreign gene instead into bacterium or virus which infects the plant cells & infects the plant cells & transfers the gene to the plant’s genetic material • “bullets” of metal particles coated w/ foreign DNA shot into cells using “gene gun” • Punch temporary holes into cell wall • Dissolve cell wall • Cells that pick up foreign gene may reproduces & develop into mature plants

12. Average milk production + BGH = 10-40% increase in milk production

13. What do all of these have in common?

14. Bio-engineered (GM) Food BrochureCAPT Embedded Task • Objective: • To assess the risk vs. benefit of genetically altered food sources using research to create a persuasive brochure that takes a position in favor of or opposed to labeling genetically altered foods.

15. Bio-engineered (GM) Food BrochureCAPT Embedded Task • Background: • The advancements in the field of biotechnology have allowed scientists to insert genes into food sources so the altered DNA produces new proteins that lead to new characteristics in the plants. By inserting a gene into a particular plant, the resulting protein may make the plant resistant to insects or resistant to a particular herbicide. The farmers’ ability to yield larger crops greatly improves when these alterations are made. Other genetic modifications improve the nutritional quality of food.

16. Bio-engineered (GM) Food BrochureCAPT Embedded Task • Many products you buy at the grocery store including corn, beets, canola and soy are probably genetically modified (genetically modified organisms are called GMOs for short), however you have no way of knowing unless the manufacturer chooses to label the product. Opponents to genetically modified food fear that future studies may uncover health risks linked to ingesting this altered form of DNA. Others suggest that the use of genetically altered plants may result in the overuse of chemicals to control weeds, and ultimately cause adverse environmental conditions. Currently there are no laws that mandate the labeling of genetically modified food products.

17. Bio-engineered (GM) Food BrochureCAPT Embedded Task • Your task is to design a persuasive pamphlet in support of or in opposition to the mandatory labeling of genetically altered food based on scientific evidence.

18. Bio-engineered (GM) Food BrochureCAPT Embedded Task • You will need to use several sources to support your stance and remember to consider the credibility of your sources when defending your position. • Here are some websites that will help start your research on the risks & benefits of GM foods. Feel free to use books & other internet resources found in the DHS or Darien Libraries. • http://pewagbiotech.org/newsroom/releases/062702.php3 • http://www.who.int/foodsafety/publications • http://actionbioscience.org/biotech/ • http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml • http://www.learner.org/courses/biology/units/gmo/index.html • http://www.learner.org/vod/vod_window.html?pid=2047 (video) • The Eyes of Nye: Genetically Modified Foods (tv show)

19. Bio-engineered (GM) Food BrochureCAPT Embedded Task • Be sure to back up your statements with FACTS (numbers, research findings). • You will want to provide answers to some of the following questions • What are the basic scientific facts and procedures used to create GMOs? • What are some of the possible ways GM foods in general (or your specific product) can increase or decrease the quality of life of those who use it? (Do they/does it increase food output per acre of land or cause death/diseases?) • Should people change to this “modern” method of farming? • Should people be concerned about using genetically modified foods? Why or why not?

20. Bio-engineered (GM) Food BrochureCAPT Embedded Task • The only rule is your brochure must be 8 ½ by 11. • Beyond the size constraint you may be as creative as you would like (the more the better) you may fold your paper, draw, type, and or decorate your brochure. • You must include a works cited and use parenthetical citations in your brochure. • The DHS Citations Style Sheet is Available on the Library Website • REMEMBER… The goal is to present your findings and cause others to join your point of view.

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