Transcript Genetic engineering

If you could choose what biologists
accomplish in your lifetime,
what would it be?
Ways in which biology is changing
our future…in the present
Traditional genetic engineering
• Selective breeding
•What is it?
•What are the
advantages (pros)
and disadvantages
(cons)?
•What is your
opinion?
Modification of organisms via
selective breeding vs. transgenesis
• Note the vector of
choice is a plasmid
Cell transformation and
Transgenic organisms
• Review all pros and cons
Example: Genetically
Modified Foods
(“Frankenfoods”?)
“Currently, up to 45 percent of U.S. corn is
genetically engineered as is 85 percent of
soybeans. It has been estimated that 70-75
percent of processed foods on supermarket
shelves--from soda to soup, crackers to
condiments--contain genetically engineered
ingredients” (?)
What are the concerns to health? To environment?
How a flounder gene ends up in strawberries
1. The flounder’s
antifreeze gene is
copied and
inserted into a
small ring of DNA
taken from a
bacteria cell.
This diagram shows how one type of
GM food, a strawberry that resists
frost damage is made.
The flounder is a fish that live in icy
seas. It has a gene that stops it from
freezing to death.Strawberries are
soft fruits that can easily be
damaged by frost.
2. The DNA ring
containing the
flounder gene is put
into a second
bacterium.
3. This second bacterium is used
to infect the strawberry cell. The
flounder’s antifreeze gene enters
the strawberry’s DNA.
4. The new GM
strawberry cell is
grown into a GM
strawberry plant
which can be bred
many times.
Strawberry cell
with Antifreeze
gene
Thanks to the new gene, GM strawberries make a
protein which helps them resist frost. They don’t
contain any other fish genes and, and do not taste or
smell of fish.
RoundUp Ready corn –
before and after RoundUp herbicide spraying
Ex.: Vaccines in Fruit
Hepatitis B vaccine has been
inserted into tomatoes and
bananas.
Why is this so important?
Ex: Mice with GFP, just because we can
How GFP got into
the mouse
Jellyfish cell
1.
Virus
Virus inserting
their DNA into
a cell
2.
3.
Mouse cell
4.
5.
The jellyfish has a gene that makes a
glowing protein. This makes the jellyfish
glow in some types of light.
The glowing gene is taken from a
jellyfish cell and spliced (inserted) into
an empty virus cell (with no bad virus in
it)
The genetically engineered virus
attaches itself to the fertilized mouse
egg cell.
The virus delivers the glowing gene into
the egg cell nucleus, where it joins the
mouse DNA.
The genetically engineered mouse egg
grows into an adult mouse which will
make the glowing protein. The glow is
too faint to see under normal lights but
can be detected using a special camera.
More GM organisms
Using the jellyfish
protein to make a
naturally glowing
Christmas tree!
Adding a gene from
insect killing bacteria to
cotton so that insects
who eat cotton will be
poisoned!
Genetically engineered
moths that pass on
deadly disease genes to
their relatives so they die
and won’t be able to
destroy crops!
A gene from a spider has
been inserted into some
goats. Their milk now
contains tiny strands of
spider silk which can be
made into a strong,
stretchy rope.
RNAi therapy
• A.k.a. RNA interference
– (see NOVA Science Now video)
Cloning
Click here to clone a mouse yourself:
http://learn.genetics.utah.edu/
• The small cat is a clone of the large one
– What does this tell us?
– You can clone your cat for $40,000
Stem cell therapy
• embryonic stem cells that
are isolated from the inner
cell mass of blastocysts
• adult stem cells are found
in various tissues and
naturally heal the body
• Specialized cells
(Unipotent) vs.
– Multipotent
– Pluripotent
– Totipotent
http://learn.genetics.utah.edu/conte
nt/tech/stemcells/scintro/
Custom-built organs
Gene therapy
• Mechanism:
Gene therapy using an Adenovirus vector. A new gene is
inserted into an adenovirus vector, which is used to introduce the modified DNA
into a human cell. If the treatment is successful, the new gene will make a
functional protein.
Gene therapy and gene doping
• What are the ethical objections to improper
gene “therapy”
Will We Be Able To Cure Cancer
With Gene Therapy?
Cancer happens when body cells grow out of control.
Scientists have found a gene called p-53 which normally
keeps cells under control. They think that in some people
with cancer, the disease begins because the p-53 gene
doesn’t work properly – perhaps because of a mistake in
the gene code. Experts are now looking for a way to cure
cancer by modifying faulty DNA to make the p-53 gene
work.
Lung cancer cells (530x). These cells are from
a tumor located in the alveolus (air sac) of a
lung.
Custom-built babies
• Gender choice
• Germ line therapy
• Designer offspring?
(watch 2 clips including GATTACA) http://www.pbs.org/wgbh/nova/genome/program_t.html
Click here to learn more:
http://www.bionetonline.org/English/Content/db_cont5.htm
Epigenetics, and why DNA is NOT your
destiny
Learn more at these links:
Interactive instruction from the University of Utah
http://learn.genetics.utah.edu/content/epigenetics/
Article in Time magazine
http://www.time.com/time/health/article/0,8599,1951968,0
0.html
For more information on all of the
aforementioned
http://learn.genetics.utah.edu/