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Genetic Engineering. Chapter 10. What we are hoping to accomplish. Define genetic engineering. Explain the principles of genetic engineering. Explain and use the tools of genetic engineering. Show and describe the practical uses of genetic engineering.
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Genetic Engineering Chapter 10
What we are hoping to accomplish • Define genetic engineering. • Explain the principles of genetic engineering. • Explain and use the tools of genetic engineering. • Show and describe the practical uses of genetic engineering. • Discuss the various steps in PCR and transformation.
Biotechnology-Genetic Engineering • The application of biological and physical principles to alter the genes of organisms to help solve human problems • Improving crops and their yield • Producing insulin in bacteria • Genetically modified vaccines • Improving the freshness of fruits and vegetables
What does genetic engineering mean? • It means to isolate a gene from the DNA of one organism and transfer the gene into the DNA of another. • We can do this because DNA is DNA in all organisms. It is made out of the same 4 nitrogen bases. The only difference is the sequence. • From there, DNA codes for RNA and proteins.
Recombinant DNA • A molecule of DNA made from pieces of DNA from separate organisms.
Restriction Enzyme • An enzyme that is used to “cut” DNA at certain places along BOTH sides of the DNA. • Most commonly used Restriction Enzymes • BamHI- G/GATTC • HindIII- A/AGCTT • HpaII- C/CGG • EcoR1- G/AATTC
Plasmids • Circular piece of DNA found in bacteria. • Replicates separate chromosome DNA • Contains very few genes • Useful because they have antibiotic resistance genes on them. • Typically used as VECTORS to transfer DNA from one organism to another.
Polymerase Chain Reaction (PCR) • A way to make an unlimited number of copies of one gene. • How? DNA Polymerase is used to replicate the same DNA segment over and over. • Why? • Increasing the number (Crime Scenes) • Sequencing (Prenatal diagnosis) • Cloning (Woolly Mammoth)
3 Steps to PCR • Denaturing- Stands of DNA separate by heating • Annealing- Reaction cooled, primers bind • Elongation- Reaction heated again, DNA polymerase replicates the rest of the DNA from primer. • Repeat steps 1-3 about 20-30x
DNA Fingerprinting • DNA is sliced into fragments called RFLPs. • DNA is then separated by sequence length by gel electrophoresis. • The result is for an individual different lengths of DNA that were cut by restriction enzymes that varies among alleles and individuals.
How the Gel Works? • DNA is negative • When DNA is placed next to a negative charge it will want to move towards the positive charge. • The heavier strands will not travel as far as the lighter strands.
Who did it? How Do We Know? Crime Scene Suspect 1 Suspect 2 Suspect 3 Suspect 4
Use in Crime Scenes • 3 different Fingerprints are run • 1/10,000 chance of matching an individual • Two fingerprints will only match 1 out of 10,000 X 10,000 times • Three matching prints would then be 1 in one trillion
The DNA • Magnified using PCR • From blood, bone, flesh, hair follicle, semen, saliva, any source of DNA • Analysis does not compare genes rather the information between genes where a great amount of variation exists • RFLP analysis
Restriction Fragment Length Polymorphism (RFLP) Analysis • Identifies locations and numbers of restriction sites of DNA.
Human Genome Project • Purpose: Sequence the entire human genome. • Why: detect, treat, and prevent genetic diseases. • Completed in 2003 • Some of their findings for human DNA • Approximately 20,000-25,000 genes (23,000) • 3 billion base pairs make up the DNA. • Only 1.5% is actually coding for protein • Still left to do? Figure out how it all fits together.
Typical Transformation Experiment • A target gene is isolated and removed by a restriction enzyme. • Another restriction enzyme will cut the DNA of a vector (plasmids) and insert our target gene. • Transfer the vector to the organism we want to modify. • Transformation- the gene becomes one with its host and replicates producing clone copies. • Screen the cells and select modified organism by identifying our gene of interest.
Why do we care? Genetically Engineered Drugs Genetically Engineered Vaccines • Humulin - Diabetes • HGH - Dwarfism • Factor VIII, Factor IX - Hemophilia • t-PA – Heart attack, clot buster • Lactoferrin – Milk protein • Herpes II • Hepatitis B • Influenza
Why do we care? Cures for Genetic Diseases Forensic Science • Cystic fibrosis • Genetic testing • Therapy • Karyotyping • DNA fingerprints • Crime • Paternity • Predisposed to disease This may involve using stem cells, by taking somatic cells (like skin cells) and dedifferentiating them down to pluripotent stem cells.
Why do we care? Plants Animals • Ti plasmid causes plant tumors • Glyphosate resistant crops (round-up ready) • Pest resistance • Improve taste and nutrition • Vaccines grown in plants • BST • Lactoferrin • Cloning