Chapter 15: Genetic Engineering

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Chapter 15 Genetic Engineering

• Section 15-3
• Applications of Genetic Engineering

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Agriculture and Industry

• Genetic engineering used to improve products we
  get from plants and animals
• Could lead to better, less expensive, more
  nutritious food, and safer manufacturing
  processes

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GM Crops

• Genetically modified plants since 1996
• Example adding bacterial genes that produce Bt
  toxin - kills insects
• No pesticides needed
• Higher crop yields
• Resistance to herbicides, viral infections, rot
  and spoilage
• Some being made to produce plastics

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GM Animals

• 30 of milk produced by cows modified with
  hormones that increase milk production
• Pigs that produce leaner meat , high levels of
  omega-3
• Salmon with extra growth hormone to make them
  grow quicker
• Canada goats that produce silk
• Goat milk with antibacterial enzymes

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GM Animals

• Scientists hoping to clone transgenic animals to
  increase food supply and save endangered species
• 2008 govt allowed sale of meat and milk from
  cloned animals
• Avoid complications of traditional breeding,
  duplicate exactly

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Preventing Disease

• Making more nutritious plants
• Producing antibodies to fight disease
• Make proteins we need

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Medical Research

• Transgenic animals used as test subjects
• Study defective genes, disease progression
• Conduct drug tests

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Treating Disease

• Recombinant DNA technology used to make human
  proteins to treat disease human growth hormone,
  insulin, blood-clotting factor, cancer-fighting
  proteins
• Also gene therapy the process of changing a
  gene to treat a medical disease or disorder
• Absent or faulty gene replaced with a normal,
  working gene

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Treating Disease

• Very risky
• Need a more reliable way to insert working genes
• Make sure its not harmful

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Genetic Testing

• Hundreds of diseases/disorders can be tested for
• Some use labeled DNA probes that can detect
  disease-causing alleles
• Some search for changes in cutting sequences
• Some use PCR to detect differences in length
  between normal and abnormal alleles

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Examining Active Genes

• Not every gene is active in ever cell all the
  time
• Understand how cells function by studying active
  genes using DNA microarray technology - measures
  level of activity of genes

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DNA Microarray

• Glass slide or silicon chip to which spots of
  single-stranded DNA are attached each spot with
  a different DNA fragment
• Colored tags label source of DNA

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DNA Microarray

• Red spots more cancer mRNA
• Green spots more normal mRNA
• Yellow spots both

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Personal Identification

• No 2 individuals are genetically identical
  (except identical twins)
• Regions of chromosomes contain repeated sequences
  that do not code for proteins that differ from
  person to person

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Personal Identification

• DNA fingerprinting analyzes sections of DNA that
  have little/no function but that vary widely from
  one individual to another
• Use REs to cut DNA into fragments,
  electrophoresis to separate fragments

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Personal Identification

• DNA probe detects fragments with highly variable
  regions
• If enough probe/enzyme combos are used, resulting
  banding pattern can be used to distinguish a
  person
• DNA from any tissue can be used

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Forensic Science

• Forensics study of crime scene evidence
• Uses DNA fingerprinting to solve crimes, overturn
  convictions
• Wildlife conservation

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Establishing Relationships

• When genes are passed parent to child, the
  markers used in DNA fingerprinting are scrambled
• Y chromosome, however, passed directly from
  father to son with few changes paternity tests
• Pieces of mitochondrial DNA (mtDNA) also passed
  from mother to child directly 2 people with the
  same mtDNA share a common maternal ancestor