Genetic Engineering Biotechnology

1. Genetic EngineeringBiotechnology

2. History of Genetic Engineering • Before technology, humans were using the process of selective breeding to produce the type of organism they want. • Creating new breeds of animals & new crops to improve our food.

3. Example: Dog Breeding Labradoodle Bullmastiff + = Labrador Poodle + = Bulldog Mastiff

4. Animal breeding

5. Breeding food plants • “Cabbage family” descendants of the wild mustard Evolution of modern corn

6. Selective Breeding • Choosing individuals with the desired traits to serve as parents for the next generation.

7. Graph: Plant Height Now, suppose only the tallest plants were used to breed • What is the result? • The frequency of desired alleles increases in the population

8. Test Cross A? A special cross use to determine an unknown genotypeof a dominant phenotype Cross the unknown individual with a homozygous recessiveindividual

9. Let’s work this out! Outcome: If the individual is homozygous dominant  100% dominant phenotype If the individual is heterozygous dominant  50% dominant phenotype  50% recessive phenotype

10. A Brave New World

11. Genetic Engineering • Scientists can now use their knowledge of the structure of DNA and its chemical properties to study and change DNA molecules.

12. Remember the code is universal • Since all living organisms… • use the same DNA • use the same code book • read their genes the same way

13. Can we mix genes from one organism to another? YES! Transgenic organisms contain recombinant DNA

14. Genetic Engineering!

15. Recombinant DNA- made by connecting fragments of DNA from a different source. Transgenic Organisms- Organisms that contain DNA from a different source.

16. How do we do mix genes? • Genetic engineering • Isolate gene from donor DNA • cut DNA in both organisms • paste gene from one organism into other organism’s DNA • transferrecombined DNA into host organism • organism copies new gene as if it were its own • organism produces NEW protein coded for by the foreign DNA Remember: we all use the same genetic code!

17. Cutting DNA • RESTRICTION ENZYMESare proteins that act as “molecular scissors”

18. Restriction Enzymes • Restriction enzymesare proteins that cut DNA • Each restriction enzyme only cuts a specific nucleotide sequence in the DNA called the recognition sequence

19. Restriction Enzymes • Recognition sequences are usually palindromes • Same backwards and forwards • Ex. Eco R1 enzyme recognizes:

20. Restriction Enzymes • Cuts usually leave little single stranded fragments called STICKY ENDS

21. Restriction Enzymes • If the enzyme cuts right down the middle, the ends are BLUNT

22. The recognition sequence for the restriction enzyme named EcoRI is CTTAAG Each time EcoRI recognizes the sequence CTTAAG, it cuts between the G & A and then through the middle of the strands This results in DNA fragments that have single-stranded tails called sticky ends

23. Restriction Enzymes • Pieces can be glued back together using LIGASE

24. http://www.youtube.com/watch?v=8rXizmLjegI

25. Gene Transfer • During GENE TRANSFER, a gene from one organism is placed into the DNA of another organism • New DNA that is created is called RECOMBINANTDNA. • Example: Human insulin Insulin Bacterial Recombinant DNA

26. Bacterial Plasmids • Bacteria have small, circular DNA segments called PLASMIDS. • Usually carry “extra info” on them • Plasmids can be used as a VECTOR- object that carries foreign DNA into a host cell

27. There’s more… • Plasmids • small extra circles of DNA • carry extra genes that bacteria can use • can be swapped between bacteria

28. transformedbacteria gene fromother organism recombinantplasmid cut DNA vector plasmid How can plasmids help us? • A way to get genes into bacteria easily • insert new gene into plasmid • insert plasmid into bacteria = vector • bacteria now expresses new gene • bacteria make new protein + glue DNA

29. Bacteria • Bacteria are great! • one-celled organisms • reproduce by mitosis • easy to grow, fast to grow • generation every ~20 minutes

30. Creation of Recombinant DNA 1. In a lab, plasmid is extracted from bacteria 2. Insulin also extracted from human DNA • **Both gene for insulin and plasmid are cut with same restriction enzyme. Insulin gene (cut from chromosome) Bacterial Plasmid

31. Transformation 4. The gene is inserted into the plasmid by connecting sticky ends with ligase. 5. Plasmid taken up by bacteria through TRANSFORMATION. 6. Bacteria grows in Petri dish and replicates recombinant DNA insulin human insulin

32. Creation of Insulin 7. As the bacteria grow and replicate, more and more bacteria are created with the human insulin gene 8. The bacteria read the gene and create insulin for us to use

33. Transforming plant & animal cells • Bacterial plasmids can also be put into plant and animal cells • The plasmid incorporates into the plant or animal cell’s chromosome Transformed bacteria introduce plasmids into plant/animal cells

34. Transgenic Organisms • Because the bacteria now has DNA from two species in it, it is known as a TRANSGENIC ORGANISM. • A.K.A. GENETICALLY MODIFIED ORGANISM

35. Transforming Bacteria Gene for human growth hormone Recombinant DNA Gene for human growth hormone DNA recombination Sticky ends Human Cell Bacterial chromosome DNA insertion Bacteria cell Bacteria cell containing gene for human growth hormone Plasmid

36. gene fromother organism recombinantplasmid + TRANSFORMATION vector plasmid CLONE growbacteria harvest (purify)protein Grow bacteria…make more transformedbacteria

37. REAL OR FAKE!!!!!

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48. Cloning

49. CLONE – organism with the same genetic make-up (DNA) as another An exact copy Cloning

50. Cloning – Step 1A