1. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 1 Manipulation of DNA Selective breeding has manipulated DNA f/ eons  Domesticated animals demonstrate the power of it  Some dogs differ dramatically from their wolf ancestors Molecular approaches now possible  Give greater power, precision and speed  We can change one gene & transfer it  Transfer between species

2. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 2 Restriction Enzymes Cut DNA at highly specific points  Four to seven bases  Each enzyme is unique Consistent results

3. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 3 Other Enzymes Ligase  Joins DNA fragments together DNA Polymerase  Makes copies of DNA of interest from a template

4. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 4 Gel Electrophoresis Separation of DNA fragments Based on size

5. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 5 Detection of Sickle-Cell

6. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 6 DNA Hybridization Radioactive DNA probe Binds only to complimentary DNA template

7. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 7 DNA Cloning Makes many identical copies of a gene  Necessary for certain operations:  Sequencing, gene transfer, hybridization DNA is obtained by screening a DNA library (a collection of different DNA pieces)

8. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 8 Screening a DNA Library One DNA is isolated from the many The library is in bacteria which are plated on agar  Form colonies  Each colony has one gene Screen by DNA hybridization  DNA probe for gene of interest  Isolate one colony and amplify it

9. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 9 Polymerase Chain Reaction (PCR) Rapid cloning by polymerase amplification Cycles through 3 temperatures  High – melting  Low – annealing of primers  Medium – polymerase extension

10. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 10 PCR

11. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 11 DNA Fingerprinting Identifies individuals & is used in:  Forensics cases  Paternity cases RFLP analysis PCR amplification

12. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 12 RFLP DNA cut with Restriction Enzyme Gel electrophoresis DNA hybridization Compare bands between suspects D V and see if match crime scene DNA

13. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 13 Genetic Engineering Transferring genes between organisms  Genetically Modified Organism (GMO) Plasmids, viruses, or gene guns Changes the phenotype  Faster growth  Insect, herbicide, disease, or frost resistance  Longer shelf-life

14. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 14 GMO

15. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 15 Human Cloning Therapeutic Cloning  Produces transplant tissues Reproductive cloning  Produces identical offspring (a clone)

16. First Gene Therapy Patient Ashanthi DeSilva 1.Born w/o a properly functioning immune system 2.ADA (adenosine deaminase deficiency)

17. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 17 Gene Therapy

18. Types of Gene therapy 1. Gene therapy currently only genetically engineers somatic cells  The correction is not inherited & has to be performed every few months.  Gene therapy that integrated into DNA did not have to be repeated, but caused cancer 2. Genetic engineering can also be done in germline, which will be inherited

19. Genetic engineering of germline Genetic engineering of people has begun! Parents will be able to make offspring at will!

20. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 20 Ethical Issues Where should the limits be drawn?  Bioengineering of bacteria, plants, dogs, humans?  Pesticide resistance – more pesticide use?  Bovine Growth Hormone – necessary?  Human cloning – therapeutic, reproductive?  Gene therapy – human bioengineering?

21. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 21 Concept Quiz What is an advantage of restriction enzymes? A. They cut DNA into manageable-sized pieces. B. They cut at a specific sequence and, therefore, give consistent results. C. They leave sticky ends which can be used in cloning. D. All of the above

22. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 22 The purpose of a DNA library is to A. Store DNA B. Isolate specific genes C. Access DNA sequence information D. Genetically modify E. coli Concept Quiz

23. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 23 RFLP analysis A. Is one method of DNA fingerprinting. B. Provides 100% accurate positive results. C. Is used in diagnosis of human diseases. D. All of the above. Concept Quiz

24. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 24 Process Animation 15.1 Genetic Testing: Identifying the Sickle-Cell Allele  Macintosh Macintosh  Windows Windows

25. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 25 Process Animation 15.2 Constructing a DNA Library  Macintosh Macintosh  Windows Windows

26. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 26 Process Animation 15.3a Human Cloning: Therapeutic Cloning  Macintosh Macintosh  Windows Windows

27. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 27 Process Animation 15.3b Human Cloning: Reproductive Cloning  Macintosh Macintosh  Windows Windows

28. © 2006 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 3/e 28 Process Animation 15.4 Genetic Engineering  Macintosh Macintosh  Windows Windows