Manipulating DNA

1. Manipulating DNA The Techniques Involved in Genetic Engineering

2. Before we begin… In addition to the information in this presentation, you should also be familiar with the corresponding information found on pages 319-325 in your textbook

3. Genetic Engineering • Genetic engineering • Altering the genetic code of a living organism in other words… • Changing the DNA of a living thing on purpose

4. The Changes… • Selective Breeding • Inbreeding • Hybridization • Molecular manipulation • Inducing mutations • DNA splicing

5. Selective Breeding • Inbreeding • The continued breeding of individuals with similar characteristics While inbreeding does maintain the characteristics of the breed, it also makes genetic defects more common

6. Selective Breeding • Hybridization • The process of mating two organisms from different species to create a hybrid

7. Selective Breeding • Hybridization • In plants

8. Selective Breeding • Hybridization • In animals

9. Selective Breeding • Hybridization • In animals

10. Selective Breeding • Hybridization • In animals

11. Molecular Manipulation • Inducing mutation • Using artificial means (for example: radiation or drugs) to cause specific mutations in living organisms

12. Molecular Manipulation • Inducing mutation • Certain mutation causes extra chromosomes leading to bigger and stronger fruiting plants

13. Molecular Manipulation • Inducing mutation • Certain mutation causes oil-eating bacteria • Used to clean up oil spills!

14. Molecular Manipulation • DNA splicing • Taking a segment of DNA from one organism and putting it into the DNA of another organism • Let’s go through the process…

15. Molecular Manipulation • DNA splicing • Extracting the DNA • Getting the DNA out of the cell and separating it from the other cell parts

16. Molecular Manipulation • DNA splicing • Cutting the DNA • Whole DNA molecules are too large to be analyzed • Scientists cut them into smaller pieces using restriction enzymes

17. More on Restriction Enzymes • A restriction enzyme is a specialized enzyme that cuts the DNA molecule at a very specific sequence • There are hundreds of restriction enzymes, each one cutting the DNA at a specific sequence • Think of restriction enzymes like a lock and key: a restriction enzyme will cut a DNA sequence only it matches precisely

18. More on Restriction Enzymes EcoR I SmaI • Cuts the DNA at the sequence CTTAAG, between the A and G • Cuts the DNA at the sequence CCCGGG, between the C and G T C T T A A G C C T C C C G G G T C C A G A A T T C G G A G G G C C C A G G T C T T A A G C C T C C C G G G T C C A G A A T T C G G A G G G C C C A G G T C C C T C T T A A A G G G G G G T C C A G G C C C C C G A G A A T T C G G

19. Molecular Manipulation • DNA splicing • Pasting the DNA • Using and enzyme called DNA ligase to attach segments of DNA

20. Molecular Manipulation • Real world application:

21. Analyzing DNA • Gel Electrophoresis • DNA that has been cut with restriction enzymes is placed in wells at one end of a porous gel • An electric voltage is applied to the gel, and the DNA which has a (-) charge moves away from the (-) charge and toward the (+) charge • The smaller the DNA particle, the farther it is able to move through the porous gel • This allows scientists to compare the DNA sequences from different individuals, or determine the relative sizes or particular genes

22. Analyzing DNA Gel Electrophoresis