1. Biotechnology
Chapter 10

2. 10.1 Impacts/Issues Golden Rice or Frankenfood?
Genes from one species may be inserted into an individual of another species – or a gene may be modified and reinserted into an individual of the same species

3. Golden Rice
Rice plants with added genes make and store beta carotene

4. Video: Golden rice or Frankenfood?

5. GMOs and Transgenic Organisms
An organism that has been genetically modified with genes from a different species
Genetically modified organisms (GMOs)
Organism whose genome has been modified by genetic engineering

6. 10.2 Finding Needles in Haystacks
Gene research was limited until enzymes produced by bacteria to cut viral DNA were discovered
Restriction enzyme
Enzyme that cuts DNA at specific base sequences
Used in DNA cloning to cut DNA into pieces that are inserted into cloning vectors

7. DNA Cloning DNA cloning mass-produces DNA fragments for research
Set of procedures that uses living cells to make many identical copies of a DNA fragment
Clone
A genetically identical copy of DNA, a cell, or an organism

8. Cloning Vectors Cloning vector Plasmid
A DNA molecule that can accept foreign DNA, resulting in a hybrid molecule that can be transferred to a host cell, and get replicated in it
Plasmid
A small, circular DNA molecule in bacteria, replicated independently of the chromosomes
A cloning vector

9. Recombinant DNA
Recombinant DNA molecules are introduced into host cells such as bacteria, which copy the DNA as they divide
Recombinant DNA
Contains genetic material from more than one organism

10. Making Recombinant DNA
1. A restriction enzyme recognizes specific base sequences in DNA from two different sources
2. Restriction enzymes cut DNA into fragments with single-stranded tails (“sticky ends”)
3. DNA fragments from different sources are mixed together; matching sticky ends base-pair
4. DNA ligase joins fragments, forming recombinant DNA

11. Making Recombinant DNA

12. restriction enzyme (cut)
1 A restriction enzyme recognizes a specific base sequence in DNA (green boxes) from two sources.
restriction enzyme (cut)
2 The enzyme cuts DNA from both sources into fragments that have sticky ends.
3 The DNA fragments from the two sources are mixed together.
The matching sticky ends base-pair with each other.
mix
DNA ligase (paste)
4 DNA ligase joins
the fragments of DNA where they overlap. Molecules of recombinant DNA
are the result.
Figure 10.2
Making recombinant DNA.
Stepped Art
Fig. 10-2, p. 181

13. Commercial Plasmid Cloning Vector

14. pDrive Cloning Vector 3.85 kb
Kpn l
Sph l
Pst l P
Bam Hl
lac
Eco RI
Kanamycin
lacZ
Sal l
pDrive Cloning Vector 3.85 kb
Acc l
Xho l
Figure 10.3
A commercial plasmid cloning vector. Restriction enzyme recognition sequences are indicated on the right by the name of the enzyme that cuts them. Researchers insert foreign DNA into the vector at these sites. Bacterial genes (green) help researchers identify host cells that take up a vector with inserted DNA.
Xba l
Bst XI
Ampicillin
Sac l
Not l
Fig. 10-3, p. 181

15. cDNA Cloning
RNA cannot be cloned directly; reverse transcriptase is used to copy single-stranded RNA into cDNA for cloning
Reverse transcriptase
Viral enzyme that uses mRNA as a template to make a strand of DNA
cDNA
DNA synthesized from an RNA template by the enzyme reverse transcriptase

16. Making cDNA

17. A The enzyme reverse transcriptase transcribes mRNA into DNA.
cDNA
B DNA polymerase replicates the DNA strand.
cDNA
Figure 10.4
Making cDNA. mRNA must be transcribed into cDNA for cloning.
cDNA
Eco RI recognition site
C The result is a double-stranded molecule of DNA that can be cut and pasted into a cloning vector.
Fig. 10-4, p. 182

18. A The enzyme reverse transcriptase transcribes mRNA into DNA.
cDNA
B DNA polymerase replicates the DNA strand.
cDNA
Eco RI recognition site
Figure 10.4
Making cDNA. mRNA must be transcribed into cDNA for cloning.
C The result is a double-stranded molecule of DNA that can be cut and pasted into a cloning vector.
Stepped Art
Fig. 10-4, p. 182

19. Libraries
A library is a collection of cells that host different fragments of DNA, often representing an organism’s entire genome
Researchers make DNA libraries to isolate one gene from the many other genes in a genome
Genome
An organism’s complete set of genetic material

20. Nucleic Acid Hybridization
Probes are used to identify one clone that hosts a DNA fragment of interest among many other clones in a DNA library
Probe
Short fragment of DNA labeled with a tracer
Hybridizes with a specific nucleotide sequence
Nucleic acid hybridization
Base-pairing between DNA or RNA from different sources

21. PCR
PCR quickly mass-produces copies of a particular DNA fragment for study
Polymerase chain reaction (PCR)
Uses primers and heat-resistant DNA polymerase to rapidly generate many copies of a DNA fragment
Primer
Short, single-strand of DNA designed to hybridize with a DNA fragment

22. Steps in PCR
1. Starting material is mixed with DNA polymerase, nucleotides and primers
2. Mixture is heated and cooled in cycles
At high temperature, DNA unwinds
At low temperature, primers base-pair with template DNA
3. Taq polymerase synthesizes complementary DNA strands on templates

23. Two Rounds of PCR

24. base-pair with the template DNA.
1 DNA template (blue) is mixed with primers (red), nucleotides, and heat-tolerant Taq DNA polymerase.
2 When the mixture is heated, the double-stranded DNA separates into single strands. zhen it is cooled, some of the primers
base-pair with the template DNA.
3 Taq polymerase begins DNA synthesis at the primers, and complementary strands of DNA form on the single-stranded templates.
Figure 10.5: Animated!
Two rounds of PCR. Each cycle of this reaction can double the number of target DNA molecules. Thirty cycles can amplify a template DNA a billionfold.
4 The mixture is heated again,
and the double-stranded DNA separates into single strands. When it is cooled, some of the primers base-pair with the template DNA.
5 Taq polymerase begins DNA synthesis at the primers, and complementary strands of DNA form on the single-stranded templates.
Fig. 10-5, p. 183

25. 4 The mixture is heated again,
1 DNA template (blue) is mixed with primers (red), nucleotides, and heat-tolerant Taq DNA polymerase.
3 Taq polymerase begins DNA synthesis at the primers, and complementary strands of DNA form on the single-stranded templates.
2 When the mixture is heated, the double-stranded DNA separates into single strands. When it is cooled, some of the primers base-pair with the template DNA.
2 When the mixture is heated, the double-stranded DNA separates into single strands. When it is cooled, some of the primers base-pair with the template DNA.
5 Taq polymerase begins DNA synthesis at the primers, and complementary strands of DNA form on the single-stranded templates.
4 The mixture is heated again,
and the double-stranded DNA separates into single strands. When it is cooled, some of the primers base-pair with the template DNA.
4 The mixture is heated again,
and the double-stranded DNA separates into single strands. When it is cooled, some of the primers base-pair with the template DNA.
Figure 10.5: Animated!
Two rounds of PCR. Each cycle of this reaction can double the number of target DNA molecules. Thirty cycles can amplify a template DNA a billionfold.
Stepped Art
Fig. 10-5, p. 183

26. Animation: Polymerase chain reaction (PCR)

27. Animation: Formation of recombinant DNA

28. Animation: Use of a radioactive probe

29. Animation: Base-pairing of DNA fragments

30. Animation: How to make cDNA

31. Animation: Restriction enzymes

32. Animation: F2 ratios interaction

33. 10.3 Studying DNA
Short tandem repeats are multiple copies of a short DNA sequence that follow one another along a chromosome
The number and distribution of short tandem repeats, unique in each individual, is revealed by electrophoresis as a DNA fingerprint

34. DNA Fingerprinting
DNA fingerprinting is used in forensics, court evidence, and other applications
DNA fingerprint
An individual’s unique array of short tandem repeats
Electrophoresis
Used to separate DNA fragments by size
tandem repeats 重複序列

35. DNA Fingerprinting: A Forensic Case

36. Evidence from Crime Scene
Size Reference
Size Reference
Size Reference
Control DNA
Size Reference
Control DNA
Control DNA
Suspect 1
Suspect 2
Female Cells
Boyfriend
Victim
Semen
Figure 10.6
DNA fingerprinting in an actual investigation of sexual assault. A short tandem repeat region was amplified from evidence at the crime scene: the perpetrator’s semen and the victim’s cells. The two samples were compared with the same tandem repeat region amplified from DNA of the victim, her boyfriend, and two suspects (1 and 2). Note the three samples of control DNA (to confirm that the PCR was working correctly), and the four size reference samples. The photo shows an x-ray film image of an electrophoresis gel from a forensics laboratory. The bands represent DNA fragments labeled with a radioactive tracer.
Figure It Out: Which of the two suspects was found to be guilty?
Answer: Suspect 1.
Fig. 10-6, p. 184

37. The Human Genome Project
Automated DNA sequencing and PCR enabled scientists to sequence the more than 3 billion bases of the human genome
Sequencing
Method of determining the order of nucleotides in DNA

38. Sequencing a Fragment of DNA
The order of colors is the order of DNA bases (A, T, G, C)

39. Genomics
Analysis of the human genome sequence is yielding new information about human genes and how they work
Genomics
The study of genomes (structural genomics, comparative genomics)

40. Some Sequenced Genomes

41. Animation: Automated DNA sequencing

42. Animation: DNA fingerprinting

43. Video: ABC News: DNA mystery: Human chimeras

44. Video: ABC News: Family ties: Paternity testing

45. 3D Animation: Gene sequencing

46. 10.4 Genetic Engineering
Recombinant DNA technology and genome analysis are the basis of genetic engineering
Genetic engineering is the directed alteration of an individual’s genome, resulting in a genetically modified organism (GMO)
Genetic engineering
Process by which deliberate changes are introduced into an individual’s genome

47. Genetically Modified Microorganisms
A transgenic organism carries a gene from a different species
Transgenic organisms are used in research, medicine, and industry
Transgenic bacteria and yeast produce medically valuable proteins

48. Designer Plants
Transgenic crop plants help farmers produce food more efficiently
Plants with modified or foreign genes are now common in farm crops

49. Using the Ti plasmid to Make a Transgenic Plant

50. 1 An A. tumefaciens bacterium has been engineered to contain a
Ti plasmid. The plasmid carries a foreign gene.
2 The bacterium infects a plant cell and transfers the Ti plasmid into it. The plasmid DNA becomes integrated into one of the cell’s chromosomes.
3 The plant cell divides, and its descendants form an embryo.
The embryo develops into
a transgenic plant.
Figure 10.8: Animated!
Using the Ti plasmid to make a transgenic plant.
5 The transgenic plant expresses the foreign gene. This tobacco plant is expressing a gene
from a firefly.
Fig. 10-8, p. 187

51. Animation: Gene transfer using a Ti plasmid

52. Genetically Modified Crops
Bt gene confers insect resistance to corn

53. Biotech Barnyards Transgenic animals produce human proteins
Animals that would be impossible to produce by traditional breeding methods are being created by genetic engineering
Transgenic animals are used in research, medicine, and industry

54. Transgenic Animals

55. Knockout Cells and Organ Factories
Transgenic animals may one day provide a source of organs and tissues for transplantation into humans
Xenotransplantation
Transplant of an organ from one species to another
異種生物器官移植(Xenotransplantation)

56. Animation: Transferring genes into plants

57. Video: ABC News: Cloned pooch

58. Video: ABC News: Mule clones
騾 Don't be a young mule(年紀輕輕, 別那麼固執)

59. Video: ABC News: Glow-in-the-dark pigs

60. Video: ABC News: Cloned food approved

61. 10.5 Genetically Modified Humans
Genes can be transferred into a person’s cells to correct a genetic defect or treat a disease
However, the outcome of altering a person’s genome remains unpredictable
Gene therapy
Transfer of a normal or modified gene into an individual with the goal of treating a genetic defect or disorder

62. Unpredictable Outcomes
There are more than 15,000 serious genetic disorders – gene therapy is the only real cure
In some cases, gene therapy works – in other cases it leads to death
Inserting a virus-injected gene into a chromosome can disrupt normal function and cause cancer
Severe allergic reaction to the viral vector can cause death

63. One Successful Case of Gene Therapy
Rhys Evans, born with a severe immune disorder (SCID-X1) received a normal gene and no longer lives in isolation

64. Getting Perfect Eugenics
Idea of deliberately improving the genetic qualities of the human race
The potential benefits of genetically modifying humans must be weighed against the potential risks, including social implications

65. 10.6 Impacts/Issues Revisited
Golden rice with beta carotene was ready for distribution in 2005 but is still not available for human consumption – the biosafety experiments required are too expensive for the public humanitarian agency that developed it

66. Digging Into Data: Enhanced Spatial Learning in Mice With Autism Mutation

67. Figure 10.11
Enhanced spatial learning ability in mice with a mutation in neuroligin 3 (R451C), compared with unmodified (wild-type) mice. (A) The mice were tested in a water maze, in which a platform is submerged a few millimeters below the surface of a deep pool of warm water. The platform is not visible to swimming mice. Mice do not particularly enjoy swimming, so they locate a hidden platform as fast as they can. When tested again, they can remember its location by checking visual cues around the edge of the pool. (B) How quickly they remember the platform’s location is a measure of spatial learning ability. The platform was moved and the experiment was repeated for the second test.
Fig a, p. 193

68. Figure 10.11
Enhanced spatial learning ability in mice with a mutation in neuroligin 3 (R451C), compared with unmodified (wild-type) mice. (A) The mice were tested in a water maze, in which a platform is submerged a few millimeters below the surface of a deep pool of warm water. The platform is not visible to swimming mice. Mice do not particularly enjoy swimming, so they locate a hidden platform as fast as they can. When tested again, they can remember its location by checking visual cues around the edge of the pool. (B) How quickly they remember the platform’s location is a measure of spatial learning ability. The platform was moved and the experiment was repeated for the second test.
Fig b, p. 193