DNA Technologies

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DNA Technologies
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Cloning

• Researchers clone animals by nuclear
  transplantation
• A nucleus of an egg cell is replaced with the
  nucleus of a somatic cell from an adult organism
• Thus far, attempts at human cloning have not
  succeeded in producing an embryo of more than 6
  cells
• Embryonic development depends on the control of
  gene expression

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Early Cloning

• Early experiments in animal nuclear
  transplantation were performed on frogs
• The cloning of tadpoles showed that the nuclei of
  differentiated animal cells retain their full
  genetic potential

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Dolly the Sheep (5 July 1996 14 February
2003) first mammal cloned
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Cloning Implications

• Reproductive cloning of non-human mammals has
  applications in basic research, agriculture, and
  medicine
• Scientists clone farm animals with specific sets
  of desirable traits
• Piglet clones might someday provide a source of
  organs for human transplant

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Genetically Modified Foods

• Inserts beneficial genes into the
  plant/organisms coding sequence
• A crop is grown up having this gene
• All organisms in this crop will have the
  specified resistance/benefit
• Ethical and biological concerns

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Gel Electrophoresis

• Restriction fragment analysis is a powerful
  method that detects differences in DNA sequences
• Scientists can compare DNA sequences of different
  individuals based on the size of the fragments
• Gel Electrophoresis relies on fragments traveling
  after a charge is applied to the gel, causing
  larger bands to remain at the top while shorter
  bands migrate farther and faster.

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DNA Fingerprinting

• Uses the products of Gel Electrophoresis in order
  to identify individuals.
• No two people (besides identical twins) will have
  the same DNA Fingerprint, so DNA analysis can be
  used to help solve crimes.

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Polymerase Chain Reaction

• Sometimes the DNA samples arent large enough to
  run tests on, so scientists must amplify the
  sample they have.
• Polymerase Chain Reaction
• quickly clone a small sample of DNA in a test
  tube
• requires raising and lowering the temperature
  inside the test tube (using a thermal cycler) to
  allow different enzymes to act.

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Gene Therapy

• Gene therapy may someday help treat a variety of
  diseases
• Techniques for manipulating DNA have potential
  for treating disease by altering an afflicted
  individuals genes
• Progress is slow, however
• There are also ethical questions related to gene
  therapy

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The Human Genome Project

• The Human Genome Project involves
• genetic and physical mapping of chromosomes
• DNA sequencing
• comparison of human genes with those of other
  species