The Good, the bad and the ugly of Genetic Engineering

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The Good, the bad and the ugly of Genetic
Engineering
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• Genetic engineering is the human manipulation of
  the DNA code of an organism in order to
• Make transgenic organisms
• Clone an organism
• Perform Gene therapy

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Transgenic Organisms

• Organisms which express a gene from another
  organism
• Insert gene of interest into another organism,
  receiving organism now makes the protein from
  that gene

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Practical applications

• Plants with insecticide genes
• Cows with extra copies of growth hormones
• Insulin making bacteria
• And most importantly (haha)

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Practical applications?

• Cool Glow-in-the-dark Mice!!

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Going back to the insulin made by bacteria

• Diabetes dysfunctional Insulin gene no or low
  amounts of insulin protein made
• we can force bacteria to make insulin for us

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• Bacteria have circular pieces of DNA called
  Plasmids
• They can replicate, transcribe and translate any
  genes on the plasmid

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• In plasmids there are also specific sequences
  called restriction sites

restriction site
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• Restriction enzymes recognize the sites and cut
  the DNA at that site

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• Each restriction enzyme recognizes and cuts a
  different sequence

Examples Rest. Enzyme Rest. Site EcoRI GAATT
C Hind III AAGCTT BamH1 GGATCC
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• Restriction enzymes recognize the sites and cut
  one strand of the DNA at that site

CACCTAGCTAG AATTCGACTAGCGAT
GTGGATCGATCTTAA GCTGATCGCTA
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• How many pieces do you get?

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• Single stranded ends are sticky
• Want to bind to complimentary bases

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• We can take advantage of this and insert any gene
  we want into the breaks
• Example The Insulin gene

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• What enzyme can we use to seal the gaps between
  plasmid DNA and insulin DNA?

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Put plasmid back into bacteria (a process called
transformation) Bacteria will transcribe and
translate our insulin gene even though the
insulin protein doesnt do anything for a
bacterial cell. Then we can take out the insulin
protein and use it to treat diabetics.
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Same basic procedure, many different transgenics!

• Giving cows extra copies of the growth hormone
  gene
• Giving plants the gene that insects have to ward
  off other enemy insects
• Giving mice the gene that jelly fish use to
  fluoresce

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Cloning

• Creating an organism that is genetically
  identical to its parent.

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Cloning

• Mammals usually fuse info from two parents
  (sexual reproduction)
• Cloning takes all the chromosomes from 1 parent.

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Zap to stimulate cell division
Implant embryo into surrogate sheep (sheep 3)
Inject nucleus into Egg
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Wait for Dolly to be born
Which sheep is Dolly identical to??
Why?
Which sheep have to be female?
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Snuppy
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Human Genome project

• What it did do Tell us each an every nucleotide
  of the human genome (all 3.2 billion)
• What it did not do Tell us what it all means!!!

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Human Genome project

• Now we have to break it down and determine
• - which pieces are genes
• - which pieces are junk
• - what info the genes hold.

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DNA finger printing

• Used to compare two peoples DNA
• Used in paternity cases
• Used for crime scene analysis

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DNA finger printing
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DNA finger printing

• Based on the idea that EVERYONEs DNA is unique,
  like a fingerprint
• BUT related individuals will have more
  similarities

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How to do a DNA fingerprint

• Get a sample of DNA and digest it with
  restriction enzymes

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How to do a DNA fingerprint

• If everyones DNA is unique, the enzyme will cut
  each persons DNA differently
• Example
• TCATGAATTCATTGCCGAATTCCGTGAATCCAGAATTCGGACTA
• TCATGAAGTCATTGCCGAATTCCGTGAATCCAGACTTCGGACTA

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How to do a DNA fingerprint

• Run cut up DNA on through electrophoresis
• Click here for animation

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How to do a DNA fingerprint

• Small pieces travel fast and move further down
  the gel slab.
• Large pieces move slower and stay closer to the
  injection point.

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Gene Therapy

• Taking genetic testing one step further
• Gene therapy tries to FIX the genetic problem

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How do we fix a gene?

• Take a virus that naturally infects the type of
  cells that are deffective.

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How do we fix a gene?

• Remove all the viruss DNA.
• Replace it with correct copy of deffective gene

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Possibilities?

1. Cystic fibrosis
2. Hemophilia
3. Cancer