Download Genetic Engineering

Genetic Engineering
Biotechnology and Recombinant DNA
Biotechnology
The use of microorganisms, cells, or cell
components to make a product:
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Foods
Vaccines
Antibiotics
Vitamins
Biodegradation
Genetic Engineering
• Manipulating an organism’s
genome to:
• alter microbes, plants, and animals
for our benefit
• correct genetic defects in humans
Ex: Golden Rice
• Created to provide
people with Vitamin A
• Developed to help the
very poor
Ex: Flavr Savr Tomato
• Created to prevent the
softening of the tomato
• Made more resistant to
rotting
• Could be “vine-ripened”
Ex: Glofish
• Inserted fluorescent
gene from a jellyfish
into zebrafish
• Sold as a pet
Ex: Roundup Ready Soybeans
• Soybeans that are
resistant to Roundup
herbicide
• Created to reduce the
application of harmful
herbicides
Bioethics Warm-Up
Which human traits do you think are
acceptable to genetically modify?
Which human traits aren’t acceptable
to genetically modify?
Bioethics Warm-Up
Would you want to know if you
were genetically predisposed to a
certain disorder (like heart
disease or diabetes)?
What if it was for a disorder that
has no known treatment?
Glowing Animals
Other Uses of Genetic Technology
• Used to identify individuals:
– Suspects in a crime (“DNA fingerprinting”)
Other Uses of Genetic Technology
• Used to identify
individuals:
– Relation between
individuals:
• Ex: paternity tests
Other Uses of Genetic Technology
• Used to identify
individuals:
– Relation between
individuals:
• Ex: University of
Arizona Shoah Project
to identify and reunite
the families of
Holocaust victims
DNA
• DNA is universal – the genetic information
from one species will work in another
species
• “DNA is DNA”
DNA 101 – Quick Refresher
• DNA formed from units called
nucleotides
• Each nucleotide is made of:
– 5 carbon sugar (deoxyribose)
– Phosphate group
– Nitrogenous base
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Adenine
Guanine
Cytosine
Thymine
DNA 101 – Quick Refresher
• In all DNA:
– A pairs with T
– C pairs with G
• Weak hydrogen
bonds form between
complimentary base
pairs
Bioethical Question
• Should a company be allowed to patent
(and own the exclusive rights of) a
genetically modified organism?
Useful Properties of DNA
• Restriction Endonuclease – enzymes used
to cut apart DNA strands
Useful Properties of DNA
• Restriction enzymes
can cut DNA at specific
sites, leaving “sticky
ends” for insertion of
new DNA
• Ligase – enzyme used
to “glue” strands
together
DNA Manipulation
Restriction Endonucleases
• Also called restriction enzymes
• 1962: “molecular scissors” discovered
in in bacteria
• E. coli bacteria have an enzymatic
immune system that recognizes and
destroys foreign DNA
• 3,000 enzymes have been identified,
many are purified and available
commercially
Restriction Endonucleases
• Named for bacterial genus, species,
strain, and type
Example: EcoR1
Genus: Escherichia
Species: coli
Strain: R
Order discovered: 1
“Sticky Ends” vs. “Blunt Ends”
Restriction Endonuclease
• Restriction enzymes recognize specific
palindromic sequences and cut them
– Palindromes: words that are the same
forwards and backwards
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Ex: Stanley Yelnats
Ex: Go hang a salami, I’m a lasagna hog
Ex: Anna
Ex: A man, a plan, a canal, Panama!
Ex: Wet sanitary rat in a stew.
Bioethical Issues
• Should we be able to
insert non-human
DNA into human
DNA?
• Would this change
what it means to be
“human”?
• Should humans be
able to alter our
intelligence via
genetic engineering?
Warm-Up
• If there aren’t any risks associated with
GM foods, should companies be required
to label foods made with GMOs?
Recombinant DNA
• Recombinant DNA:
DNA from two or
more species that
has been joined
together
• Transgenic:
organisms altered by
genetic engineering
Warm-Up
• Genetic pollution: undesired and uncontrolled
gene flow from GMOs into wild populations
• What are the implications of “genetic pollution”?
• Should we try to prevent “genetic pollution”?
Other Uses