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Genetically Modified Crop Plants. Genetic Engineers Can Modify Food. Transgenic organisms are produced when a gene from one organism is incorporated into the genome of another The more popular term for transgenic organisms is GMO , for genetically modified organism
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Genetic Engineers CanModify Food • Transgenic organisms are produced when a gene from one organism is incorporated into the genome of another • The more popular term for transgenic organisms is GMO, for genetically modified organism • GM foods means genetically modified
Pros to GMOs • Better resistance to weeds, pests, disease • Better texture, flavor, nutritional value • Longer shelf life, easier shipment • Better yield, more efficient use of land • Less herbicides and other chemicals • Essential if we are to feed the world
Cons to GMOs • They can have harmful effects on the human body • It is believed that consumption of these genetically engineered foods can cause the development of diseases which are immune to antibiotics. • These foods are new inventions, not much is not known about their long term effects on human beings. As the health effects are unknown, many people prefer to stay away from genetically modified foods
Cons to the Environment • Creates “super weeds” • Creates “super bugs” • Effects natural ecosystems
Bt and the Monarch butterfly • Bacillus thuringiensis (Bt) is a soil bacterium that produces insecticidal toxins. • Genes from Bt can be inserted into crop plants to make them capable of producing an insecticidal toxin and therefore resistant to certain pests. • Bt corn can adversely affect non-target insects if they are closely related to the target pest, as is the case with Monarch butterfly
Genetically Modified Foods in the U.S. Diet • Over half of all food in U.S. market contain at least some GM foods • Most soybeans grown are modified for herbicide resistance • GM corn – an ingredient in most processed foods – is common as well • GM canola and cottonseed oils are used in a huge range of food products
FDA Regulations • Manufactures must get FDA approval for an food not generally recognized as safe (GRAS), including new genetically engineered food substances • The FDA declared milk from rBGH cows safe for consumption in 1993
How Are GM Foods Evaluated for Safety? • The EPA must approve all GM crops • GM foods can cause allergic reactions (8% of us are allergic to foods) • Newly inserted genes may also encode proteins that prove to be toxins
Genetic Engineering/ DNA Technology • 3 types of Cloning Technologies: • Recombinant DNA Technology/ DNA Cloning • 2. Reproductive Cloning • 3. Therapeutic Cloning
Recombinant DNA Technology/ DNA Cloning
Cloning a Gene • Cloning means making many copies of a gene
Recombinant DNA Technology/DNA Cloning 1. Remove the Gene of Interest 2. Cut the Plasmid DNA 3. Insert the Gene into the Bacterial Plasmid 4. Insert the Recombined Plasmid into the Bacterial Cell 5. Let the Bacteria Reproduce
1. Remove the gene of interest (ex: BGH gene) using restriction enzymes Restriction enzymes cut DNA at specific sequences called palindromes . . .
Restriction Enzymes • The unpaired bases on the sticky ends form bonds with any complementary bases with which they come into contact
3. Insert the Gene of Interest into the Bacterial Plasmid (The bacterial plasmid is also cut with the restriction enzyme, leaving sticky ends)
Other Proteins Made by DNA Cloning: • Insulin for diabetics • Clotting factors for hemophiliacs
Basic Versus Applied Research Basic research • no profit motive or direct commercial application – generally government funded Applied research • immediate and profitable application – generally privately funded
Reproductive Cloning • Technology used to generate an animal that has the same nuclear DNA as another curretly or previously existing animal
Results of Nuclear Transfer Experiments There were 277 failures before this nuclear transfer technique succeeded;
Reproductive Cloning Dolly was successfully born in 1997
Reproductive Cloning • Dolly was put to sleep at the age of 6 in 2003 • She was suffering from arthritis and a progressive lung disease • These are usually only seen in old sheep
Other Organisms Reproductively Cloned Mouse Cow Goat Mule Horse Rabbit Cat Pig Dog Rat Deer
Therapeutic Cloning/ Embryo Cloning • Instead of cloning entire organisms, there is therapeutic cloning • Stem cells are induced to turn into specific tissue cells
The Human Genome Project Sequenced the entire human genome
Organisms With Genome Sequenced Fruit Fly Potato Zebra fish Rhesus Macaque
Many organisms have genome projects that have either been completed or will be completed shortly, including • : • Humans • Neanderthal • Haemophilus influenzae, a bacterium • Common House Mouse • Brown Rat • Common Chimpanzee • Rhesus Monkey • Domestic Chicken • Domestic Cat • Domestic Dog • Common fruit fly • Baker's yeast