Cancer, Stem Cells, and DNA Technology CHAPTER 12

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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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Restriction Enzymes Cut DNA in Specific Places

• This splicing process can be accomplished using
  restriction enzymes.
• These enzymes cut DNA at specific nucleotide
  sequences.
• These cuts produce pieces of DNA called
  restriction fragments
• That may have sticky ends that are important
  for joining DNA from different sources.

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Recombinant DNA Techniques

• Plasmids are small, circular DNA molecules that
  are separate from the much larger bacterial
  chromosome.

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Genes Can Be Spliced Into Plasmids
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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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Recombinant DNA Technology (Genetic Engineering)
Figure 12.2
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Applications of DNA Technology GM Foods

• Today, DNA technology is quickly replacing
  traditional plant-breeding programs.
• In the United States today, roughly one-half of
  the corn crop and over three-quarters of the
  soybean and cotton crops are genetically modified.

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Applications of DNA Technology GM Foods II

• Golden rice has been genetically modified to
  contain beta-carotene.
• Our bodies use beta-carotene to make vitamin A.

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Applications of DNA Technology Pharm Animals

• While transgenic plants are used today as
  commercial products, transgenic whole animals are
  currently only in the testing phase.
• These transgenic sheep carry a gene for a human
  blood protein.
• This protein may help in the treatment of cystic
  fibrosis.

• While transgenic animals are currently used to
  produce potentially useful proteins, none are yet
  found in our food supply.
• It is possible that DNA technology will
  eventually replace traditional animal breeding.

Transgenic animals raised for the purposes of
producting pharmaceuticals are called pharm
animals
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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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DNA Fingerprinting and Forensic Science

• DNA technology has rapidly revolutionized the
  field of forensics.
• Forensics is the scientific analysis of evidence
  from crime scenes.
• DNA fingerprinting can be used to determine
  whether or not two samples of genetic material
  are from a particular individual.

• It can also show how related two organisms are to
  each other by the similarity of their DNA
  fingerprints

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DNA Fingerprinting Generates Banding Patterns
Unique to Individuals

• Collect cells
• Extract DNA
• Cut the DNA in fragments using the same
  restriction enzyme
• 4. Separate the fragments using gel
  electrophoresis

Figure 12.12
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The Polymerase Chain Reaction (PCR)

• The polymerase chain reaction (PCR) is a
  technique by which any segment of DNA can be
  copied quickly and precisely.
• Through PCR, scientists can obtain enough DNA
  from even minute amounts of blood or other tissue
  to allow DNA fingerprinting.
• A single DNA molecule can be replicated in a test
  tube to make 30 million identical copies in a few
  hours
• Formerly DNA fingerprinting was not possible
  because too little DNA was available at a crime
  scene

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Polymerase Chain Reaction DNA Replication in a
Test Tube
Exponential Increase in the Number of DNA
Molecules each Cycle
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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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The Human Genome Project

• In 1990, an international consortium of
  government-funded researchers began the Human
  Genome Project.
• The goal of the project was to sequence the human
  genome so scientists could have roadmap for
  finding genes

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Safety and Ethical Issues

• Safety
• Moving genes into other organisms could create
  hazardous new pathogens
• Strict laboratory safety procedures have been
  designed to protect researchers from infection by
  engineered microbes

• Concerns of GM Foods
• Crops carrying genes from other species might
  harm the environment.
• GM foods could be hazardous to human health.
• Transgenic plants might pass their genes to close
  relatives in nearby wild areas.

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Ethical Issues About Biotechnology

• Should genetically engineered human growth
  hormone be used to stimulate growth in
  HGH-deficient children? To stimulate growth in
  normal children, making them tall enough to excel
  in basketball or volleyball?
• Should we try to eliminate genetic defects in our
  children?
• Advances in genetic fingerprinting raise privacy
  issues. Who should have access to your genetic
  information?
• Should medical insurance companies know if you
  are genetically likely to develop cancer?

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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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Therapeutic Cloning and Stem Cells

• Stem cells are early-stage cells that can develop
  into any organ or tissue of the body.
• If the right chemical signals can be added to
  stem cells, they can potentially grow into
  replacement organs.
• Stem cells can be taken from a fetus after
  abortion, from umbillical cord blood, or from
  adult stem cells (such as those that form blood
  cells)

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Cloning

• A clone is a genetic duplicate of an existing
  organism
• Many plants are easily cloned by taking a piece
  of the plant and cultivating it

Cloning a carrot
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Reproductive Cloning of Animals

• Nuclear transplantation
• Involves replacing nuclei of egg cells with
  nuclei from differentiated cells.
• Has been used to clone a variety of animals.

• Scottish researchers cloned the first mammal in
  1997.
• Dolly, the sheep, was the product of their work.
• The procedure that produced Dolly is called
  reproductive cloning.

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The Cloning of Dolly the Sheep
Figure 11.13
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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• Genetic Engineering/Gene Splicing
• Achievements and Dangers of Recombinant DNA
  Technology
• DNA Fingerprinting and Gel Electrophoresis
• Polymerase Chain Reaction
• Human Genome Project
• Safety and Ethics
• Stem Cells and Cloning
• Cancer Genes, Prevention, and Risk

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Cancer Genes (Oncogenes) Result From Damaged
Proto-Oncogenes
Unrestricted mitosis resulting in tumors (cancer)
Figure 11.18
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Cancer Risk and Prevention

• Cancer
• Is one of the leading causes of death in the
  United States.
• Breast, lung, colon, skin, and prostate cancers
  most common

• Examples of carcinogens
• UV radiation
• Tobacco
• Alcohol
• Certain chemicals like formaldehyde, radon gas

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Cancer, Stem Cells, and DNA TechnologyCHAPTER 12

• Uses of Recombinant DNA Technology
• Recombinant Techniques
• Restriction Enzymes
• DNA Fingerprinting and Gel Electrophoresis
• Genomics and Proteomics
• Gene Therapy
• Safety and Ethics
• Cancer Genes, Prevention, and Risk
• Stem Cells and Cloning