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Genetically Modified Organisms

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Presentation on theme: "Genetically Modified Organisms"— Presentation transcript:

1 Genetically Modified Organisms
Biology 1

2 What is a Genetically Modified (GM) Food?
Foods that contain an added or deleted gene sequence Animal products from animals fed GM feed Products produced by GM organisms A GM food is one that has sequences of DNA from another organism inserted into its genome in order to get a desired phenotype. The definition of GM foods may also include foods that have an a deleted gene, foods such as cheese that are made from enzymes that are from a genetically modified organism, and foods such as beef that have been fed genetically modified feed. 2

3 Why are foods genetically modified?
Scientists are able to isolate specific genes, and they can insert those genes into organisms -- especially food crops - - to produce desirable traits. Changing one base pair (A-T or C-G), deleting a whole region of DNA, or introducing an additional copy of agene Why are new genes introduced? A)grow higher yields, b)make crops more resistant to infection and pests, or even to c)infuse them with extra nutrients and vitamins. Genetic engineering offers a rapid and precise method of altering organisms as compared to traditional methods that are slow and inaccurate. Traditionally, plants and animals were selectively mated in order to get desired phenotypes. This took many generations to improve organisms. 3

4 Common GM Foods Corn (85% of corn in GM): found in beer, salad dressing, margarine, flour, and anything that has corn syrup. Many producers modify corn and soy so they are resistant to herbicide Soy: most heavily genetically modified; the largest US producer created a GM soybean approved in 2010. It is modified to have a high level of oleic acid, which is naturally found in olive oil. Oleic acid is a monounsaturated fatty acid thought of as "bad" cholesterol 4

5 Common GM Foods Milk: rBGH is a hormone produced in GM bacteria which produces higher milk yields; a synthetic hormone approved by FDA in 1993 (but banned in Europe, Canada) It is not clear that drinking milk, produced with or without rBGH treatment, increases blood IGF-1 levels into a range that might increase cancer risk Canola Oil: 90% of crops transgenic; canola (rapeseed) produces a top pollen for honey Alfalfa: Cultivation of genetically engineered alfalfa was approved in 2007; has a gene that makes it resistant to the herbicide, Roundup 5

6 How is genetic modification possible?
The components of DNA are the same in all organisms. The sequence of the components is the “recipe for the proteins” Sequences that code for proteins can be moved from one organism to another. The components that make up DNA are the same in all organisms. The sequence of these components is the “ recipe” for the proteins synthesized by different organisms. Proteins are responsible for the characteristics exhibited by life forms. By taking the DNA sequence that codes for a protein responsible for a desirable characteristic and putting it into the DNA (Genome) of another organism; the desired characteristic will be expressed. The new sequence will begin to make the intended protein. 6

7 How can DNA be moved from one organism to another?
Genetic Modification with the example: insulin Normally insulin is produced in the pancreas, but in people with type 1 diabetes,  there is a problem They inject insulin to control blood sugar levels.  Genetic engineered insulin is like our own and is made from yeast and bacteria (like E. coli) This genetically modified insulin, ‘Humulin’ was licensed for human use in 1982.  A good example is insect resistant corn. The bacteria Bacillus turingiensis has a gene that directs the synthesis of a protein that is toxic to some insects and benign to others. 7

8 The Genetic Engineering Process - Insulin
1. A small piece of circular DNA (plasmid) extracted from bacteria or yeast cell. 2. Small section cut out of plasmid by restriction enzymes, ‘molecular scissors’. 3. Human insulin gene inserted into the gap in the plasmid. (It is now GM) 4. GM plasmid introduced into a new bacteria or yeast cell. 5. This cell divides rapidly and makes insulin. 6. For large amounts of cells, the GM bacteria or yeast grow in large fermentation vessels with needed nutrients. 8

9 The Genetic Engineering Process
7. After fermentation, mixture is filtered to release insulin. 8. Insulin then purified and packaged into bottles and insulin pens for distribution to patients with diabetes 9

10 Traits that Have Been Modified

11 Possible Benefits of GM Foods
Easing of world hunger Development of crops that can be grown in marginal soil Reduced strain on nonrenewable resources Development of drought resistant crops Development of salt- tolerant crops Development of crops that make more efficient use of nitrogen and other nutrients 11

12 Possible Benefits of GM Foods
Reduced use of pesticides and herbicides Development of pest resistant crops Reduced herbicide use is better for the environment and reduces costs for farmers 12

13 Possible Benefits of GM Foods
Improved crop quality Development of frost resistant crops Development of disease resistant crops Development of flood resistant crops Improved nutritional quality Development of foods designed to meet specific nutritional goals 13

14 Possible Risks of GM Foods
Insects might develop resistance to pesticide- producing GM crops Herbicide-tolerant crops may cross- pollinate weeds, resulting in "superweeds“ There may be unintended harm to wildlife and beneficial insects 14

15 Possible Risks for GM Foods
There are issues between farmers who choose to use GM crops and those that don’t Pollen from GM crop gets blown into neighboring field and pollinates those fields as well Photo courtesy of T. W. Davies, Cal. Acad. of Sciences. 15

16 Possible Risks for GM Foods
Some crops have been engineered to be more resistant to herbicides. There is a “motivation” to use more chemical herbicides (without harming the crops) 16

17 Possible Risks for GM Foods
Toxicity: each insertion of a gene is in effect “random” There is hope that the new genetic information doesn’t destabilize a food and make a safe food unsafe Allergic Reactions: can genetic engineering transfer allergens from one food to another? Ex. When a gene from a Brazil nut was transferred into soybeans, those with nut allergies had large reaction (and without labeling, people cannot know) Antibiotic Resistance: could make disease causing bacteria more resistant to antibiotics which would lead to spread of infections in humans. 17

18 Possible Risks for GM Foods
Immunosuppression: one study found that rats consuming GM potatoes showed lower immune function and improper organ development (many studies have confirmed this) Cancer: some reasons Europeans and Canadians have banned rBGH is because it increases levels of IGF-1 in the body (which has shown to increase incidence of breast, prostate and colon cancer) Potential Loss of Nutrition with GM 18

19 Who makes sure GM foods are safe?
Government agencies regulate GM foods GM foods in the United States are required to be labeled only if the nutritional value is changed or a new allergen is introduced. 19

20 Top 10 Transgenic Animals: Brainbow Mouse
-Harvard scientists used 4 fluorescent proteins in varying combinations and saturations which made images of brain cells in 100 different shades. -The colorful cells were individual neurons helped scientists distinguish one cell from another can differentiate between different parts of nerve cells and even map nerve connections. By understanding neurons and connectivity, scientists can help people with nerve disorders or help people with nerve therapy.

21 Top 10 Transgenic Animals: Spider Goat
Scientists extract the silk protein from milk of transgenic goats that have the spider silk gene inserted into their DNA. Biosteel is 7-10 x as strong as steel, can stretch up to 20 x without losing its strength properties; has very high resistance to extreme temperatures Technology applied to bulletproof vests, artificial tendons, clothing. PROCESS: female goats lactate; the milk, containing the recombinant DNA silk, is harvested and silk proteins are purified and dried;  transformed into nanofibers using the electrospinning technique.

22 Top 10 Transgenic Animals: Cancer-Proof Mouse
University of Kentucky scientists revealed a mouse that was resistant to spontaneous and artificially induced tumors. Its inability to get cancer is due to the insertion of a gene that codes for a protein called Par-4. This protein specifically kills cancer cells without affecting normal cells.

23 Top 10 Transgenic Animals: Emerald Sea Slug
First known naturally occurring transgenic species How did the genes transfer from plants to animals? the slug “steals” chloroplasts from algae and then stashes them in its own digestive cells. They also have a gene that makes a key enzyme that repairs damaged chloroplasts and keeps them working.

24 Top 10 Transgenic Animals: Glofish
These zebrafish have had fluorescent proteins extracted from jellyfish inserted into their DNA to make them glow green, orange, or red. To study water pollutants these fish had genes inserted for proteins that would fluoresce in the presence of certain contaminants Pose a threat to wildlife?

25 Top 10 Transgenic Animals: Aedes Mosquito
Mosquitoes carry many infectious diseases scientists can inject small amounts of DNA into mosquito egg. In a few eggs, new DNA will be taken up by the cells and will be cut and pasted into the mosquito’s genome. If it happens in the sperm cells of a male or egg- producing cells of a female, the new DNA can be passed on to their offspring. the eggs hatch; mosquitos are cared for and bred if injected DNA has entered sperm or egg cells, then it will be passed on to their offspring. (The injected DNA contains the lethal gene and a fluorescent gene which allows them to be identified. This transgenic strategy "could become a major component of an integrated program" to fight mosquito-mediated diseases.

26 Top 10 Transgenic Animals: Mighty Mouse
They can run for 25 times as long as normal mice at the same speed, and they eat more and live longer. The mice are genetically altered to overproduce an enzyme, PEPCK-C (helps make glucose). These mice generate little lactic acid Good models for studying aging in humans.

27 Top 10 Transgenic Animals: Drug Producing Chicken
The chicken egg is a simple and efficient factory for making pharmaceutical proteins A goal is to produce an egg that contains an antibody against a viral, diarrheal disease of the gut 2010-FDA approved a chicken that has been genetically engineered to produce a drug in its eggs. Known as ‘farmaceuticals,’ these transgenic chicken eggs will contain a recombinant human enzyme that replaces a faulty enzyme in people with a rare, inherited condition that prevents the body from breaking down fatty molecules in cells.

28 Top 10 Transgenic Animals: Fearless Mouse
Rutgers’ scientists removed a gene for stathmin, an enzyme that is found in high levels in the part of the brain that regulates emotions and fears. Mice don’t have normal fears like fears of open spaces; reduces their ability to learn to fear things, such as a tone that is always followed by an electric shock. The amygdalas of people with anxiety disorders have high levels of the stathmin protein. We could possibly help people with emotional responses to fear.

29 Top 10 Transgenic Animals: Enviropig
Pig manure has lots of Phosphorus which kills marine species and generates greenhouse gases Transgenic pigs produce phytase that breaks down phosphorus efficiently. Phosphorus is the major nutrient causing algal growth leading to fish kills and reduced water quality The low phosphorus manure from Enviropigs has a reduced environmental impact (These pigs produce 75% less phosphorus).


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