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DNA TECHNOLOGY
O.J. Simpson capital murder case,1/95-9/95
Odds of blood in Ford Bronco not being R. Goldman’s:
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6.5 billion to 1
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Odds of blood on socks in bedroom not being N. Brown-Simpson’s:
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8.5 billion to 1
Odds of blood on glove not being from R. Goldman, N. Brown-Simpson, and O.J.
Simpson:
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21.5 billion to 1
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Number of people on planet earth:
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6.1 billion
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Odds of being struck by lightning in the U.S.:
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2.8 million to 1
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Odds of winning the Georgia’s Big Game lottery:
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76 million to 1
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Odds of getting killed driving to the gas station to buy a lottery ticket
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4.5 million to 1
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Odds of seeing 3 albino deer at the same time:
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85 million to 1
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Odds of having quintuplets:
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85 million to 1
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Odds of being struck by a meteorite:
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10 trillion to 1
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Biotechnology
Biotechnology, defined broadly, is the engineering of organisms for useful
purposes.
Often, biotechnology involves the creation of hybrid genes and their introduction
into organisms in which some or all of the gene is not normally present.
Recombinant DNA is DNA in which genes from 2 different sources are linked.
Fourteen month-old genetically engineered (“biotech”) salmon (left) and
standard salmon (right).
Manipulating Genes
DNA Technology can be used to:
*cure diseases
*to treat genetic disorders
*to improve food crops
*and to improve the lives of humans
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Biotechnology Tools
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Restriction Enzymes- used to isolate a specific
gene
Cloning Vectors- a carrier that is used to clone a
gene and transfer it from one organism to
another. Example: Plasmid
Plasmids are Used to Replicate a Recombinant DNA
*Plasmids are small circles of DNA found in bacteria.
*Plasmids replicate independently of the bacterial chromosome.
*Pieces of foreign DNA can be added within a plasmid to create a recombinant
plasmid.
*Replication often produces 50-100 copies of a recombinant plasmid in
each cell.
Restriction Enzymes are Enzymes That Cut DNA Only at
Specific Sequences
Restriction
enzyme
animation
The enzyme EcoRI cutting DNA at its recognition sequence
Different restriction enzymes have different recognition sequences.
This makes it possible to create a wide variety of different gene fragments.
Forming Recombinant DNA using Restriction Enzymes:
Harnessing the Power of Recombinant DNA Technology –
Human Insulin Production by Bacteria
Human Insulin Production by Bacteria
and cut with a restriction enzyme
6) join the plasmid and human fragment
Human Insulin Production by Bacteria
Mix the recombinant plasmid
with bacteria.
Route to the Production by Bacteria of Human Insulin
One cell with the
recombinant plasmid
This is the step when gene cloning takes place.
A fermentor used to grow
recombinant bacteria.
The single recombinant plasmid replicates within a cell.
Then the single cell with many recombinant plasmids produces trillions
of like cells with recombinant plasmid – and the human insulin gene.
Route to the Production by Bacteria of Human Insulin
The final steps are to collect the bacteria, break open the cells, and purify
the insulin protein expressed from the recombinant human insulin gene.
Bacterial plasmids in gene cloning
DNA Technology Tools….
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Polymerase Chain Reaction (DNA copying)
Gel Electrophoresis
DNA Fingerprinting
Cloning
Copying DNA
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Polymerase Chain Reaction
Also called PCR
A method of making many copies of a piece of
DNA
Steps in Copying DNA
•
•
A DNA molecule is placed in a small
test tube
DNA polymerase that can work at
high temps is added
Steps in Copying DNA
The DNA is heated to
separate the two
strands
 Primers, short pieces of
DNA complementary to
the ends of the
molecule to be copied,
are added
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Copying DNA
•
The tube is cooled, and DNA
polymerase adds new bases to the
separated strands
PCR
Large amounts of DNA can be made
from a small starting sample
Electrophoresis
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DNA can be separated
based on size and charge
The phosphate groups are
negatively charged
DNA is placed in a gel and
electricity is run through
Electrophoresis
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Negative DNA moves toward
the positive end
Smaller fragments move
farther and faster
Electrophoresis
DNA Fingerprinting
DNA is now a powerful tool in identification.
Based on the fact that the amount of "junk DNA" differs uniquely
between individuals.
Structural genes are often separated by large regions of repeating
basepairs.
The number of these repeats is unique to an individual.
Therefore when DNA from a person is cut with a restriction enzyme,
the length of the fragments will be unique to an individual.
DNA Fingerprinting Continued…
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This will therefore
produce a unique
banding pattern
following a gel
electrophoresis.
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This test is highly
accurate, and the
probability of
another individual
possessing an
identical banding
pattern is
estimated as
around
1:14,000,000,000.
DNA Fingerprinting
DNA Fingerprint
EV shows the DNA at a crime scene. Samples 1-5
were taken and analyzed from suspects. Based
on this evidence, which suspect is guilty?
Cloning
 Cloning is the process of making a
genetically identical organism through
nonsexual means. It has been used for
many years to produce plants (even
growing a plant from a cutting is a
type of cloning). Animal cloning has
been the subject of scientific
experiments for years, but garnered
little attention until the birth of the
first cloned mammal in 1997, a sheep
named Dolly. Since Dolly, several
scientists have cloned other animals,
including cows and mice. The recent
success in cloning animals has sparked
fierce debates among scientists,
politicians and the general public
about the use and morality of cloning
plants, animals and possibly humans
Dolly, the first mammal clone
This shows how a common type of
reproductive cloning works:
Dolly the Sheep
Dolly died in 2003. This
was due to lung disease
and crippling arthritis.
Most sheep can live 1112 years. Dolly was 6.5
years old.
Human Genome Project
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Started in 1990-finished in 2003
Research effort to sequence all of
our DNA (46 chromosomes)
Over 3.3 billion nucleotides in
roughly 26,000 genes
Mapping every gene location (loci)
Conducted by scientists around the
world
HGP Insights…what they learned
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Only 2% of human genome codes
for proteins (exons)
Other 98% (introns) are noncoding
Only about 26,000 genes
(expected 100,000)
Proteome – organism’s complete
set of proteins
About 8 million single nucleotide
polymorphisms (SNP) – places
where humans differ by a single
nucleotide
Benefits of Human Genome
Project
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Improvements in medical prevention of
disease, gene therapies, diagnosis
techniques …
Production of useful protein products for
use in medicine, agriculture, bioremediation
and pharmaceutical industries.
Improved bioinformatics – using computers
to help in DNA sequencing …
Gene Therapy
Gene therapy can be used to treat some genetic
disorders. It is utilized when a a defective “unhealthy”
gene is replaced with normal “healthy” gene. Here are
some diseases that gene therapy may help with more
research:
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Cystic fibrosis
Hemophilia
Lung Cancer
AIDS
Ovarian Cancer
Brain tumors
Example of gene therapy
1. Insert DNA version
of normal allele
into virus.
Insert a gene into an inactivated or
nonvirulent virus and use the virus's
infective capabilities to carry the
desired gene into the patient's cells.
2. Let virus infect bone marrow cells
that have been removed from the
patient and cultured.
3. Viral DNA
carrying the
normal
allele
inserted into
chromosome.
What factors have kept gene therapy from becoming an
effective treatment for genetic disease?
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Immune response
Problems with viral vectors
Multigene disorders
Biotechnology
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The use of gene science to create new
products from plants and animals
Biotechnology Provides:
Improved food products
Medical advances
Biotechnology Breakthroughs….
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Insulin (1982)
 First commercial biotech product
 Reliable, inexpensive source of insulin
Rice
 Enriched with beta-carotene and iron
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Bananas
 Containing edible hepatitis vaccine
Potatoes with higher solid content
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Garlic that lowers cholesterol
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Fruits and vegetables that reduce risks of cancer
and heart disease
Herbicide Resistant Crops
+ CP4 EPSPS = Roundup
gene
Ready
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Soybeans:
Corn:
Cotton:
Canola:
Roundup Ready
Roundup Ready, Liberty Link
BXN, Roundup Ready
Liberty Link, Roundup Ready