Biotechnology

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Biotechnology
Dolly and surrogate Mom
Embryonic stem cells and gene therapy
Genetically modified rice.
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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.
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Biotechnology
Well examine
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Animal Cloning
Dolly and her surrogate mother.
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Is Animal Cloning Ethical?
The first cloned horse and her surrogate
mother/genetic twin.
As with many important questions, the answer is
beyond the scope of science.
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The Biotechnology of Reproductive Cloning
Even under the best of circumstances, the current
technology of cloning is very inefficient.
Cloning provides the most direct demonstration
that all cells of an individual share a common
genetic blueprint.
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Saved by Cloning?
Some are firm believers while many view these
approaches to be more of a stunt.
Note the use of a closely related species, a
domestic goat, as egg donor and surrogate mother.
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Carbon Copy the First Cloned Pet
Significantly, Carbon Copy is not a phenotypic
carbon copy of the animal she was cloned from.
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The Next Step?
Highly unlikely.
Attempts at human cloning are viewed very
unfavorably in the scientific community.
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Recombinant DNA, Gene Cloning, and Pharmaceutical
Production
These are mature and widely utilized
biotechnologies.
DNA can be cut at specific sequences using
restriction enzymes.
This creates DNA fragments useful for gene
cloning.
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Restriction Enzymes are Enzymes That Cut DNA Only
at Particular Sequences
Restriction enzyme animation
Different restriction enzymes have different
recognition sequences.
This makes it possible to create a wide variety
of different gene fragments.
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DNAs Cut by a Restriction Enzyme Can be Joined
Together in New Ways
These are recombinant DNAs and they often are
made of DNAs from different organisms.
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Harnessing the Power of Recombinant DNA
Technology Human Insulin Production by Bacteria
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Human Insulin Production by Bacteria
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Human Insulin Production by Bacteria
Screening bacterial cells to learn which contain
the human insulin gene is the hard part.
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Route to the Production by Bacteria of Human
Insulin
This is the step when gene cloning takes place.
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.
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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.
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Route to the Production by Bacteria of Human
Insulin
Overview of gene cloning.
Cloning animation
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DNA, the Law, and Many Other Applications The
Technology of DNA Fingerprinting
A DNA fingerprint used in a murder case.
The defendant stated that the blood on his
clothing was his.
What are we looking at? How was it produced?
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DNA Fingerprinting Basics
Different individuals carry different alleles.
Most alleles useful for DNA fingerprinting differ
on the basis of the number of repetitive DNA
sequences they contain.
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DNA Fingerprinting Basics
If DNA is cut with a restriction enzyme that
recognizes sites on either side of the region
that varies, DNA fragments of different sizes
will be produced.
A DNA fingerprint is made by analyzing the sizes
of DNA fragments produced from a number of
different sites in the genome that vary in
length.
The more common the length variation at a
particular site and the greater the number the
sites analyzed, the more informative the
fingerprint.
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DNA charge

• Phosphate groups
• Found between sugars of DNA structure
• Negatively charged
• Gives DNA an overall negative charge (polar)
• Remember like charges repel
• Opposites attract

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A Site With Three Alleles Useful for DNA
Fingerprinting
DNA fragments of different size will be produced
by a restriction enzyme that cuts at the points
shown by the arrows.
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The DNA Fragments Are Separated on the Basis of
Size
The technique is gel electrophoresis.
The pattern of DNA bands is compared between each
sample loaded on the gel.
Gel electrophoresis animation
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Possible Patterns for a Single Gene With Three
Alleles
In a standard DNA fingerprint, about a dozen
sites are analyzed, with each site having many
possible alleles.
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A DNA Fingerprint
When many genes are analyzed, each with many
different alleles, the chance that two patterns
match by coincidence is vanishingly small.
DNA detective animation
HGP fingerprinting page
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DNA and the Law
Some applications of DNA fingerprinting in the
justice system.
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Genetically Modified Foods
Many of our crops in the US are genetically
modified.
Should they be?
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GM Crops are Here Today
Source Pew Initiative on Food and Biotechnology,
August 2004.
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Methods for Plant Genetic Engineering are
Well-Developed and Similar to Those for Animals
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Golden Rice is Modified to be Provide a Dietary
Source of Vitamin A
Worldwide, 7 of children suffer vitamin A
deficiency, many of them living in regions in
which rice is a staple of the diet.
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Genetically Modified Crops
Genetically Modified Cotton (contains a
bacterial gene for pest resistance)
Standard Cotton
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GMOs, Especially Outside the US, Are a Divisive
Issue
Protesters at the 2000 Montreal World Trade Summit
European sentiment
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Current Concerns by Scientists Focus on
Environmental, Not Health, Effects of GM Crops
The jurys still out on the magnitude of GM
crops ecological impact, but the question is
debated seriously.
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Current Concerns by Scientists Focus on
Environmental, Not Health, Effects of GM Crops