1. Biotechnology

2. Breeding
The first biotechnology

3. Selective Breeding
The breeding of organisms to produce certain desired traits in their offspring

4. Used to produce a new breed with a desired trait
Only the ones with the desired trait are selected to reproduce
Persian

5. Inbreeding Crossing organisms that have a similar genotype
Used to maintain a desired set of traits
Can result in problems and undesirable traits (p. 207)
German
Shepherd
Sharpei

6. Outbreeding (hybridization)
The crossing of distantly related organisms
Usually involves two breeds of the same species
Liger
Mule

8. Genetic Engineering
Any technique used to identify or change genes at the molecular level
Involves the building of Recombinant DNA
A molecule made from pieces of DNA from separate organisms

9. All genetic engineering experiments share 4 steps:
Cleaving DNA – a desired gene is cut from DNA
Producing Recombinant DNA – DNA fragment is put into the DNA of another cell

10. Cloning cells – growing a large number of genetically identical cells from a single cell
Screening cells – cells that received the gene of interest are identified and isolated

11. Step 1: Cleaving DNA
Enzymes called restriction enzymes are used to cut a DNA molecule into fragments

12. Restriction enzyme cuts out the desired gene from the DNA molecule at a specific nucleotide sequence

13. The incision is not at the center of the sequence but is staggered to one side
The cut produces fragments with exposed nitrogen bases called “sticky ends”

14. DNA code GAATTC
GAATTC
CTTAAG
G AATTC
CTTAA G
one end: G “sticky
CTTAA end”
other end: AATTC “sticky
G end”

15. Sticky ends can pair with any other DNA fragment that has been cut with the same restriction enzyme

16. Step 2: Producing Recombinant DNA
Restriction enzyme is used to cut open a plasmid

17. A plasmid is a small circular piece of DNA found in a bacterium that is separate from the bacterial chromosome
The plasmid serves as a vector – a carrier of genetic material

18. Open plasmid and isolated gene are combined
Sticky ends join and are sealed by the enzyme DNA ligase
New combined DNA molecule is called Recombinant DNA

19. Step 3: Cloning Cells
The recombinant plasmid is introduced into a bacterial cell
Cells with the new plasmid reproduce making copies of the new gene
This is called Gene Cloning

20. Step 4: Screening Cells
The new bacterial cells are screened to see if they have the new gene
The ones with the gene are isolated

21. Example:
The gene for human insulin can be isolated and inserted into a plasmid
Bacterial cells then produce human insulin

22. This is used by people who are diabetic
Reduces the need for pig insulin which can cause allergic reactions

23. Identifying Sequences in DNA
DNA Fingerprint
DNA is cut into fragments by a restriction enzyme

24. Because of differences in nucleotide sequences, the number of cutting sites for a restriction enzyme varies among the DNA of different individuals producing fragments of different lengths
The lengths are unique to each individual

25. Samples are separated by a process called Gel Electrophoresis
a. DNA fragments are dropped into thin slits in a track of gel

26. The gel tracks have a (+) charge at one end and a (-) charge at the opposite end
DNA has a (-) charge so the fragments move toward the (+) end of the gel

27. The smallest fragments move farthest along the tracks and the larger fragments stay toward the (+) end
e. A unique banding pattern is produced
f. Every person’s DNA has a unique pattern that can be used for identification

28. Gel electrophoresis can also be used to find the base-pair sequence of DNA
Four different chemicals are used to recognize and cut four samples of the same DNA at each of the four bases (A, T, C, G)

29. The samples are then poured into four gel electrophoresis tracks
Computers can read the order of the bases by analyzing the bands in the tracks

30. Human Genome Project
The effort to identify the nitrogenous base sequence of all the DNA in every human chromosome
Officially completed in April 2003

31. Gel electrophoresis can be used to determine if a person carries a genetic disorder
The person’s pattern of DNA bands is compared with the pattern known to be associated with the disease
If the two patterns match, that person may develop the disorder

32. Biotechnology and Medicine

33. Making genetically engineered drugs
The human gene for insulin can be inserted into bacteria so the bacteria produce human insulin
Human insulin is the first commercial product of genetic engineering

34. Other medically important proteins made using genetic engineering techniques:
Anticoagulants – proteins involved in dissolving blood clots are used to treat heart attack patients

35. Genetically engineered Factor VIII is used to treat hemophilia patients
This factor is free of viruses (HIV and Hepatitis B)

36. Making genetically engineered vaccines
Bacteria are genetically engineered to act as antibodies and are safer than using a weakened form of a disease-causing virus

37. Curing Genetic Disorders
Treatment involves changing the genes that cause a genetic disorder

38. Example: Cystic Fibrosis
Secretion of excess mucus in the lungs caused by a malfunctioning gene
This method has already had some success

40. Healthy genes that have recombined with certain viruses or carrier cells can be delivered to lung cells via a nasal spray
The healthy genes can replace the malfunctioning genes, correcting the genetic defect

42. The New Agriculture

43. Making crops resistance to herbicides and insects
The gene that is resistant to herbicides is inserted into plants
The farmer treats the field with an herbicide and everything dies except the plants with the new gene
Makes weed control easier

44. Making crops that need no fertilizer
Genetically engineering crops to fix nitrogen
Crops can be grown without adding fertilizer

45. Improving livestock production
Growth hormone in the diet of dairy cows improves milk production
The source of growth hormone has been extracting it from the brains of dead cows

46. The gene for growth hormone can now be inserted into bacteria so the bacteria produce the hormone
This method is much less expensive and there is less chance of passing on disease (such as prion, ie. Mad Cow Disease) to the dairy cows

47. Bioinformatics

48. The use of computers to manipulate and analyze the growing quantities of genetic information available to the pharmaceutical, biomedicine and biotechnology industries