Manipulating the Genome

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Manipulating the Genome
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• Nowadays we can take out a gene from one organism
  and put it into another organism
• Uses
• Modify crops
• Research diseases
• Produce insulin for diabetics

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Tools of Genetic Engineering

• Two tools are used to cut out a gene from one
  organism and insert it into another
• Plasmids small circular pieces of DNA that can
  exit and enter bacterial cells
• Restriction enzymes like chemical scissors that
  can cut DNA at specific sequences of bases.

Example EcoR1 restriction enzyme always cuts at
GAATTC and leaves sticky ends
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• Recombinant DNA is a fragment of DNA made up of
  nucleotide sequences from at least two different
  sources.
• Recombinant DNA will use a plasmid cut with the
  same restriction enzyme as the inserted DNA so
  they match up at the sticky ends and produce a
  continuous circle again.

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Gene Therapy

• New technique where scientists try to overcome
  the negative effects of a defective gene by
  adding a normal gene.
• The cells in which the gene needs to be replaced
  are called the target cells.
• You need something to carry the specialized DNA
  sequence that is fixed which is called the
  vector.
• We use plasmids for vectors, but they dont work
  in mammalian cells, so we use viruses instead.

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How it works

• 1. Scientists alter viral DNA so it cannot harm
  human cells.
• 2. Copies of the DNA that include the normal
  human gene are placed inside each virus and
  incorporated into the viral DNA
• 3. Large numbers of these viruses are used to
  infect the target cells in attempt to insert the
  normal human DNA into the cells genome.

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Not widely used

• Gene therapy is still in the testing phases.
• There have been some successes and failures, but
  we it is still a work in progress