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Today’ s Agenda:. Journal Questions: (1) Describe what you know about DNA. (2) What is genetic engineering (Biotechnology)? *1. Lecture: Genetic Engineering (Biotechnology) & Recombinant DNA Technology -slide …. 80. Genetically Modified (GM) Crops around the World. Genetic Engineering.
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Today’ s Agenda: • Journal Questions: (1) Describe what you know about DNA. (2) What is genetic engineering (Biotechnology)? *1. Lecture: Genetic Engineering (Biotechnology) & Recombinant DNA Technology -slide …. 80
Genetic Engineering Dr. Rick Woodward
DNA, the Law, and Many Other Applications – The Technology of DNA Fingerprinting A DNA fingerprint used in a murder case. The defendant stated that the blood on his clothing was not his. What are we looking at? How was it produced?
DNA Fingerprinting Basics A. Different individuals carry different alleles. B. Most alleles useful for DNA fingerprinting differ on the basis of the number of repetitive DNA sequences they contain.
DNA Fingerprinting Basics A DNA fingerprint is made by analyzing the sizes of DNA fragments produced from a number of different sites in the genome that vary in length.
The DNA Fragments Are Separated on the Basis of Size The technique is gel electrophoresis. The pattern of DNA bands is compared between each sample loaded on the gel.
Gel Electophoresis A. Technique used to separate nucleic acids or proteins by size and charge.
California Biology Content Standards: California Content Standards: 5 b. Students know how to apply base-pairing rules to explain precise copying of DNA. 5 c. Students know how genetic engineering (biotechnology) is used to produce novel biomedical and agricultural products. 5 e. Students know how exogenous DNA can be inserted into bacterial cells to alter their genetic makeup and support expression of new protein products.
DNA Review: A. Structure: Double Helix B. Location: Nucleus of Cell C. Function: “Blue print of Life” – Creation of Proteins/Amino Acids – Transcription. D. Nitrogen Base: ATCG E. Nucleotide: Phosphate, Sugar (Deoxyribose), Nitrogen Base (ATCG). F. Base Pairing Rules: A-T C-G
Genetically Modified (GM) Food Genetically Modified Cotton (contains a bacterial gene for pest resistance) Standard Cotton
What is Genetic Engineering? “Genetic engineering is the technology for modifying the genetic information in a plant, animal or human in order to produce some desired trait or characteristic”
Genetic Engineering Vocabulary A. Restriction Enzymes “molecular scissors”are enzymes that cut DNA only at particular sequences. B. Plasmids are small circles of DNA found in bacteria. C. Plasmids are used to replicate a recombinant DNA. D. Vector - A vector is a small piece of DNA used to carry a gene of interest.
The enzyme EcoRI cutting DNA at its recognition sequence Restriction Enzymes are Enzymes that Cut DNA Only at Particular Sequences Different restriction enzymes have different recognition sequences.
DNA Cut by a Restriction EnzymesCan be Joined Together in New Ways These are recombinant DNAs and they often are made of DNAs from different organisms.
Plasmids are Used to Replicate a Recombinant DNA A. Plasmids are small circles of DNA found in bacteria. B. Plasmids replicate independently of the bacterial chromosome.
Human Insulin Production by Bacteria 1. Isolate human cells and grow them in tissue culture. 2. Isolate DNA from the human cells. 3. Isolate plasmid DNA from a bacterium. 4. Use the same restriction enzyme to cut the plasmid DNA. 5. Mix the recombinant plasmid with bacteria. 6. Allow the new bacteria to incorporate the recombinant plasmid into the bacterial cell. 7. Grow trillions of new insulin producing bacteria (this is when cloning takes place). 8. A fermentor is used to grow recombinant bacteria. 9. Collect the bacteria, break open the cells and purify the insulin protein.
Harnessing the Power of Recombinant DNA Technology – Human Insulin Production by Bacteria
Human Insulin Production by Bacteria and cut with a restriction enzyme 6) join the plasmid and human fragment
Mix the recombinant plasmid with bacteria. Human Insulin Production by Bacteria Screening bacterial cells to learn which contain the human insulin gene is the hard part.
One cell with the recombinant plasmid A fermentor used to grow recombinant bacteria. Route to the Production by Bacteria of Human Insulin This is the step when gene cloning takes place. The single recombinant plasmid replicates within a cell.
Route to the Production by Bacteria of Human Insulin The final steps are to collect the bacteria, break open the cells, and purify the insulin protein expressed from the recombinant human insulin gene.
Overview of gene cloning. Route to the Production by Bacteria of Human Insulin.
Monday (March 12, 2012)Genetic Engineering • Journal Question: What is a plasmid? *1. Lecture II: Genetic Engineering 2. Comprehensive Exam next Monday.
Banking Genes A. The massive Svalbard Global Seed Vault is built into the permafrost deep in a mountain on a remote arctic island in Norway
Banking on Genes B. Built in 2008 After receiving its first deposits, a “doomsday” seed vault on an Arctic island has amassed half a million seed samples, making it the world’s most diverse repository of crop seeds.
Most Widely Used Genetically Modified Crops are… 1. Cotton plants with a built-in resistance to insects.
Most Widely Used Genetically Modified Crops are… 2. Corn and Soybeans resistant to the herbicide Roundup. a. Allowing Farmers to employ no-till techniques to farming.
Which country is the leader in plant biotechnology? Answer: China A. They have recently sequenced the rice genome.
Problems with Genetic Engineering Technology 1. Environmental Problems 2. Food Safety 3. Access to the New Techniques
Environmental Problems A. Pest –resistant properties of transgenic crops. B. If pests have a broad exposure to the toxin or some other resistance incorporated into the plant, it is possible that they will develop resistance to the toxin and thus render it ineffective as an independent pesticide.
Food Safety A. Food safety issues arise because transgenic crops contain proteins from different organisms and could trigger an unexpected allergic response to people who consume the food.
Access to the New Techniques A. Relates to the developing world. B. Farmers in the developing countries are unable to afford the higher cost of the new genetically altered seeds.
Other Types of Genetic Engineering: 1. Transgenic Engineering a. Putting genetic information from one type of plant or animal into another. 2. Cloning a. Making exact genetic copies of an existing plant or animal.
Transgenic Organisms A. An organism is called “transgenic” if it has genetic information added to it from a different type of organism. B. Viruses do something of this sort when they infect plants, animals or humans. C. Humans have begun to do this with plants and animals.
Transgenic Organisms D. This is the work that is furthest along: (1) Corn with its own insecticide. (2) Soybeans & cotton resistant to herbicides. (3) Papayasresistant to viruses
Transgenic Organisms F. Human genes have been inserted into: (1) Bacteria (Prokaryotes) (2) Mice G. To produce various human proteins for treating diseases.
Advantages of Transgenic Organisms A. Plants: (1) More disease-resistant. (2) Larger yields. (3) More transportable. B. Animals: (1) Make proteins for medicinal purposes. (2) Make organs for transplant to humans.
Cloning: “Exact Copies” A. A “clone” is an exact copy. B. In genetics, a clone is a genetic copy of another organism. C. Clones occur naturally: • Asexual breeding in plants & lower animals • Identical twins (triplets) in higher animals D. For centuries it has been known that simple animals – worms & starfish – can be cloned by cutting them in half. E. This doesn’t work for higher animals! F. Part of the problem is cell specialization: • Nerve, Bone, Muscle, etc.
Cloning in the 20th Century A. We now realize that each specialized cell has all the genetic information, but much of it is turned off. B. Problem – how to reset the “program” so this information is usable? C. Cloning of frogs successful in 1950s D. Cloning of livestock from fetal cells in 1970s.