Biotechnology

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Biotechnology
Guess the lambs name
DOLLY!--THIS IS A PHOTO OF THE FAMOUS CLONED SHEEP
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Goals of Applied Genetics

1. Help humans create crops that can be frost
   resistant
2. Use transgenic organisms to help medical
   researchers model human physiology for testing
3. Help industry to create bacteria to break down
   pollutants into harmless products
4. Pharmaceutical companies use recombinant DNA to
   cheaply produce human hormones (insulin) and
   other proteins
5. Help solve crimes and determine familial
   relationships

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Selective breeding

• Selecting organisms with the most desirable
  traits
• Requires time and several generations to produce
  offspring with the desired trait
• Ex
• Short vs long haired cats
• Milk production in cattle
• Disease resistant foods
• Bacteria that break down oil

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Genetic Engineering

• Also called, recombinant DNA technology or gene
  cloning
• Uses a bacterial host because of fast
  reproduction and a circular DNA vehicle to hold
  the foreign DNAplasmid
• Organisms containing recombinant DNA or foreign
  DNA are known as transgenic

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Steps involved

1. select the desired gene(s) to be inserted into
   the organism and a bacterial host containing a
   plasmid (vehicle to hold the desired gene)
2. cut specific DNA molecules into fragments with
   special (restriction) enzymes
3. splice (rejoin) the fragments (gene and plasmid)
   together in the desired combination
4. introduce or insert the new DNA into a living
   cell for replication (mitosis)

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Vector to transfer DNA
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Restriction Enzymes

• Used to cut a DNA molecule at a specific
  nucleotide sequence
• Produces one of two types of DNA fragments
• Sticky ends (palindrome)
• Blunt ends

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Sticky Ends (palindrome)
Blunt ends
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Vector to transfer DNA
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Vectors

• Vector in nature, an organism that can transmit
  DNA to another organism, often an infection
• Biotechnology uses this ability to transfer
  desired genetic information to a host cell.

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Gene Libraries

• Store DNA sequences for biotech applications
• May use plasmid or phage
• (Phage virus that infects bacteria and looks
  like a spaceship)
• May contain entire genome or only DNA used in
  gene expression.
• Expressed DNA is called cDNA (complementary DNA)
  and is made from mRNA with the enzyme...

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Reverse Transcriptase!!!!
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Gene Cloning

• Used to produce genetically identical copies of a
  cell, tissue, organ, and/or organism
• Needed to produce multiple copies of the desired
  DNA

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Cloning Applications

• Currently
• Plants are cloned to produce a large number of
  genetically identical plants in a short amount of
  time
• Future?
• Clone productive and healthy animals to increase
  yield for farmers and to grow organs for
  transplants

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How it works.
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Gene Therapy

• The insertion of normal genes into human cells to
  correct genetic disorders like cystic fibrosis.

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DNA Fingerprinting

1. Obtain a small sample of DNA
2. Make millions of copies using PCR (polymerase
   chain reaction) technique
3. Cleave (cut) DNA with restriction enzymes
4. Separate DNA fragments using gel electrophoresis
   and compare
5. Each humans DNA will have some unique pieces
   because each of our DNA is unique

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Restriction Fragment Length Polymorphism (RFLP)

• RFLP Each individual..
• ...has different numbers of restriction sites
• ...different of base pairs between restriction
  sites
• Gel electrophoresis is used to create a DNA
  fingerprint of these unique sizes.
• Small amounts of DNA are loaded into wells in the
  gel.
• An electric current pushes the small pieces of
  DNA farther down the gel than the larger pieces.

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RFLP

• DNA patterns are compared to known patterns.
• Used for forensics, blood samples, and paternity
  tests (children get half their bands from mom and
  half from dad)

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Running a gel
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How DNA moves
Step 1 Pour gel with comb for wells, not
unlike a jello mold.
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Step 2 Pipette DNA into wells. DNA has been
cut with restriction enzymes.
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Step 3 Run an electric current to watch DNA
migrate. Small strands, fewer base pairs,
travel further.
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Step 4 Notice similarities and differences in
banding patterns.
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The Human Genome Project

• There are approximately 80,000 genes on the 46
  human chromosomes
• Human Genome Project- an international effort to
  completely map and sequence human chromosomes
  (April 2003)

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Southern Blotting

• Purpose to use a cloned gene to probe for the
  same gene in another sample.
• Named for Edward M. Southern-
• Western and Northern Blots play on that name
• These have slightly different procedure (Western
  involves protein rather than DNA)

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Southern Blotting

• Unknown DNA is run on a gel.
• DNA bands are blotted onto special paper.
• Paper is flooded with labeled complementary DNA

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Southern Blotting

• Hybridization Single stranded DNA probe binds to
  any complementary DNA on paper, and the rest is
  washed off
• Bands that are hybridized are radioactive and can
  be visualized.
• http//www.accessexcellence.org/RC/VL/GG/ecb/south
  ern_blotting.html

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Uses of Radioactive Probes

• Biochemists use radioactive probes to find things
  such as
• Genes
• Proteins
• Enzymes
• Receptors on membranes
• Antigens (by using radioactive antibodies)

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Bioinformatics

• This area of study uses genetic material (or any
  biological material) to gather information.
• Such as

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Bioinformatics

• Whether a gene is similar to a previously
  sequenced gene.
• Whether a specific gene is correlated with a
  specific disease, such as which genes are
  prevalent in cancer cells.
• Whether a certain drug can benefit or harm a
  patient based on the patients genotype.

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Credits

• This Power Point was provided by Abby Price and
  modified by Andrea Wise, Providence High School,
  2007