Genetic Engineering

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Genetic Engineering

• Genetic Engineering is the process of making
  changes in the DNA code of living organisms.
• Genetic Engineering and DNA Technology can be
  used to
• Cure diseases
• Treat genetic disorders
• Improve food crops
• Produce vaccines and
• other useful drugs

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Genetic Engineering Includes

• Selective Breeding Crossbreeding
• Recombinant DNA
• Transgenic Organisms
• PCR
• DNA Fingerprinting
• Gel Electrophoresis
• Cloning

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Selective Breeding

• Breed only those plants or animals with desirable
  traits
• People have been using selective breeding for
  1000s of years with farm crops and domesticated
  animals.

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Hybridization (Crossbreeding)

• Producing new organisms by the mating individuals
  of different breeds, varieties, or species
• Male Donkey Female Horse Mule

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Recombinant DNA

• rDNA has been artificially created
• DNA from two or more sources is recombined into a
  single molecule
• To create rDNA, scientists use restriction
  enzymes to cut DNA in precise locations

• Restriction enzymes create sticky ends that
  allow the DNA to bind to another piece of DNA
  with the same sticky ends

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Recombinant Bacteria

• Remove a Plasmid
• A plasmid is a small circular piece of DNA found
  in bacteria
• Cut the Bacterial DNA with restriction enzymes
• Cut the desired gene from another organisms DNA
  with restriction enzymes
• Combine the cut pieces of DNA together and insert
  them into bacteria.
• Reproduce the recombinant bacteria.
• The foreign genes will be expressed in the
  bacteria.

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Recombinant Bacteria
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Benefits of Recombinant Bacteria

• Bacteria can make human insulin or human growth
  hormone.
• Bacteria can be engineered to eat oil spills.

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Transgenic Organisms

• The genetic code is universal, therefore it is
  possible to make organisms that are transgenic
• Transgenic organisms contain genes from other
  species
• They are also called GMOs Genetically Modified
  Organisms

This tobacco plant glows in the dark because
scientists gave it the gene that causes fireflies
to glow
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Transgenic Plants

• Disease-resistant and insect-resistant crops
• Hardier fruit
• 70-75 of food in supermarket is genetically
  modified.

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Transgenic Animals

• Mice used to study human immune system
• Chickens more resistant to infections
• Cows increase milk supply and leaner meat
• Goats, sheep and pigs produce human proteins in
  their milk

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Polymerase Chain ReactionPCR

• PCR is a fast and inexpensive technique used to
  amplify (copy) small amounts of DNA
• Heat the DNA so it unzips.
• 2. Add the complementary nitrogenous bases.
• 3. Allow DNA to cool so the complementary
  strands can zip together.

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DNA Fingerprinting

• A technique used by scientists to distinguish
  between individuals of the same species using
  only samples of their DNA
• Unless they are identical twins, individual
  organisms all have unique DNA.

• The chemical structure of the DNA may be the same
  (A, T, C G), but the order of the base pairs is
  different

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DNA Fingerprinting Process

• First, DNA must be obained from blood, bodily
  fluids, hair roots, skin, or elsewhere
• After the DNA is isolated, it is amplified using
  PCR
• Then the DNA is treated with restriction enzymes
• Cut the DNA at specific sequences
• This results in different sized fragments
• These fragments are separated, based on size,
  using a process called Gel Electrophoresis

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Gel Electrophoresis

• DNA fragments are separated as they migrate
  through an agarose gel matrix
• This size-based separation occurs when an
  electric current is applied to the gel

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Gel Electrophoresis

• DNA is a negatively charged molecule, so it will
  move toward the positive end of the chamber

• The smaller fragments will move faster and
  farther than the larger fragments

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Gel Electrophoresis Steps

• 1. Cut DNA sample with restriction enzymes.
• 2. Run the DNA fragments through a gel.
• 3. Bands will form in the gel.
• 4. Everyones DNA bands are unique and can be
  used to identify a person.

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DNA Fingerprinting

• DNA fingerprinting can show which individuals are
  the parents of specific children
• A childs DNA fragments must be inherited from
  his or her biological parents

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DNA Fingerprinting

• DNA fingerprinting can also be used to help solve
  crimes

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Cloning

• Cloning is the creation of an organism that is an
  exact genetic copy of another
• Their DNA is identical
• Produced by asexual reproduction
• Mitosis

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Cloning

• Dolly the sheep was the first animal to be
  successfully cloned in 1997
• There were 277 failures before this nuclear
  transfer technique succeeded