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Lecture14BIO115Winter11d2l - BIO 115 DNA Technology Dr...

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Unformatted text preview: BIO 115 DNA Technology Dr. Jessica Pamment Definition of Biotechnology Definition of Biotechnology • The use of microorganisms, such as bacteria or yeasts, or biological substances, such as enzymes, to perform specific industrial or manufacturing processes • Applications include: 1.Production of certain drugs, synthetic hormones, 2.Bioconversion of organic waste 3.Use of genetically altered bacteria in the cleanup of oil spills Overview Overview • Biotechnology history and applications • Recombinant DNA technology • Applications of DNA technology in our lives • Social and ethical issues History History • Biotechnology started with the agricultural revolution around 10,000 B.C. • Beer making started around 6,000 B.C. • Modern biotech started with the discovery of DNA structure and sequencing of genomes genomes to obtain desired results • Present day biotech involves manipulating Recombinant DNA Techniques Recombinant DNA Techniques • DNA cloning • Expressing cloned genes • The Polymerase Chain Reaction (PCR) • DNA sequencing • Gene therapy DNA Cloning DNA Cloning • • • • i. ii. Provides a way of working directly with gene of interest Method used to make multiple copies of well­ defined DNA segments Commonly an E. coli plasmid is used to clone gene of interest Outcomes are : Make many copies of gene of interest Make protein product of interest DNA Cloning DNA Biostoning Biostoning • Productivity can be increased by 30­50% with use of enzymes compared to use of pumice stones • There is no need for the time­consuming and expensive task of removing stone fragments from the jeans once the wash is done. employee health or gritty sediment to clog drains. • There is also no pumice dust to endanger • Environmentally friendly Restriction Enzymes Restriction Enzymes • One of main tools used for cloning • Made by bacteria to digest foreign DNA • Specific enzymes that cut both DNA strands at precise points within restriction site • Restriction sites usually 4 to 8 nucleotides • Enzymes will cut to result in restriction fragments Cutting and Pasting DNA with restriction enzymes enzymes Cutting and Pasting DNA with restriction enzymes enzymes Cutting and Pasting DNA with restriction enzymes enzymes Bacterial Plasmids Bacterial Plasmids • A type of cloning vector: a DNA molecule that can carry foreign DNA into a host cell and replicate there • Easily isolated • Easily manipulated to form recombinant plasmids in vitro bacteria • Multiply rapidly due to high reproductive rate of A plasmid is separate and replicates independently A plasmid is separate and replicates independently of chromosomal DNA DNA Cloning DNA DNA Cloning DNA DNA Cloning DNA DNA Cloning DNA Applications of DNA Technology Applications of DNA Technology • Production of insulin • Genetically modified foods • Farm and “Pharm” animals Production of Humulin Production of Humulin • World’s first genetically engineered pharm product • Produced by bacteria that express the human insulin gene • Produced in large vats • Used by people with diabetes who can’t produce their own insulin Vats with insulin producing bacteria Vats Glowing Fish Glowing Genetically Modified Crops Genetically Modified Crops • DNA technology is replacing traditional breeding programs • Genetic engineering can create plants with exact desired characteristics very rapidly • In US, approx. 50% of corn crop and 75% of soybean and cotton crops are GM’d Genetically Modified Corn Genetically Genetically Modified Rice Genetically “Pharm” Animals • Transgenic farm animals engineered to produce proteins to benefit humans • Transgenic animals are harder to make than transgenic plants • Transgenic animals used only to make useful proteins, not for food Genetically Modified Sheep Sheep A Genetically Modified Swine Genetically Transgenic Rubber Trees yields human Transgenic Rubber Trees yields human protein in sap • Albumin is a vital protein needed is needed for accident and surgery victims • You can get continual production just by tapping rubber trees • As protein manufacturing factories, plants are solar­powered and ecologically friendly • 70% of the sticky liquid tapped from the tree consists of the protein DNA Fingerprinting and Forensic DNA Fingerprinting and Forensic Science • The analysis of DNA fragments to determine who they come from • Applications include identification of murderer in crime scene; paternity; evolution research • Techniques include: PCR; STR analysis; gel electrophoresis Cheddar Man and his descendant Cheddar DNA fingerprinting in solving a crime case case Gel Electrophoresis of DNA Molecules Gel Visualization of DNA in an EB gel under UV light Visualization The Polymerase Chain Reaction (PCR) The Polymerase Chain Reaction (PCR) • Method for amplifying DNA found in small amounts • Can make billions of copies of a target segment in a few hours • PCR is a three step cycle that produces an exponential increase in identical DNA molecules DNA Amplification by PCR by Need: DNA of interest Nucleotides DNA polymerase Short Tandem Repeat Analysis Short Tandem Repeat Analysis • STRs are short, noncoding DNA segments that are repeated in tandem • The number of repeats varies between individuals • STRs are used as genetic markers • STR analysis usually compares 13 STRs Short Tandem Repeat (STR) Sites Short Visualizing STR Fragment Patterns Visualizing Human Gene Therapy Human Gene Therapy • This procedure involves inserting ‘healthy’ genes into an individual for therapeutic purposes • Holds great potential for treating conditions caused by single gene • Still little evidence of safe and effective gene therapy Gene Therapy Gene Therapy • Is a technique for correcting defective genes responsible for disease development • Several approaches: 1. Normal gene inserted randomly into genome 2. Abnormal gene swapped for normal gene Gene Therapy Gene SCID SCID • Severe combined immunodeficiency, ‘bubble boy’ disease • Rare, 1/200,000 births • It was fatal until recent years • Several underlying genetic mutations but all have the same effect, an individual who lacks almost all immune defenses SCID SCID • Treatments: • Bone marrow and cord blood transplants, • http://www.bionews.org.uk/page_82400.asp only known cure • Gene therapy, has been successful in treating X­SCID but still experimental stages Bubble Boy Bubble Boy Bubble Boy Bubble Boy Gene Therapy to treat SCID Gene Therapy to treat SCID Safety and Ethical Issues Safety and Ethical Issues • Strict lab safety guidelines developed for working with recombinant DNA technology survive outside the lab • Microorganisms used are made so they won’t • Applications of biotech evaluated for potential risks by several regulatory agencies • Concern about GM foods (mainly plants) Genetically Modified Foods Genetically Modified Foods Comes from plants that have had their DNA modified in the lab to enhance desired traits Faster and more accurate than traditional breeding programs In US 60% of all processed foods contains GM ingredients Controversial: introduction of allergens, creation of ‘superweeds’ No convincing evidence that GM foods pose a real health threat Figure 12.25 Figure GMO Food Controversy GMO Ethical Questions Ethical Questions • Do we have the right to examine somebody else’s genetic information? • How should the information be used? • Should DNA ‘defects’ be corrected? Summary Summary • Recombinant DNA technology enables scientists to isolate and clone DNA of interest in order to study its function enzymes and cloning vector • DNA cloning involves use of restriction • Cloning a gene is a method of making many copies of gene of interest Summary • PCR as an alternative way to make many copies of gene of interest when starting material is scarce • Gel electrophoresis to separate nucleic acids or proteins dependent on size Summary Summary • Practical applications of DNA technology affect our every day lives agriculture, environment • Applications in the fields of medicine, • Safety and ethical concerns Recombinant DNA Techniques Techniques •What is recombinant DNA? – a. DNA that is produced as a result of crossing over – b. DNA that carries genes from different organisms – c. DNA that carries oncogenes – d. an alternate form of DNA that is the product of mutation ANSWER BACK TO GAME •How does a vaccine work? – – – – a. it inhibits bacterial reproduction b. it kills cells infected with a virus c. it provides temporary immunity to a pathogen d. it stimulates the immune system ANSWER BACK TO GAME Chapter 12 Chapter 12 ______. $300 Question • Restriction enzymes are obtained from – a. archaea – b. bacteria – c. eukaryotes – d. retroviruses ANSWER BACK TO GAME •What name is given to a region of DNA that is, with the exception of identical twins, unique to each individual? – – – – a. genetic marker b. codon c. genetic probe d. restriction fragment ANSWER BACK TO GAME •Gel electrophoresis separates DNA fragments primarily on the basis of differences in their __________. – – – – a. G:T ratio b. C:T ratio c. A:G ratio d. length ANSWER Cloning in the media Cloning Dogbird Magritte cloning The cloning of Mona Lisa ...
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