Genetic Engineering

13
-
4: Genetic Engineering

GMOs

Genetically Modified Organisms

Take a gene from a
sea anemone that
makes them glow in
the dark and insert it
into the DNA of a
puppy and
BAM
!
…

Not for sale
in the U.S
.

With the increasing ability of
humans to manipulate genes, we
are now able to use
genetic

engineering

technology for man’s
benefit.




This field of industry is called
biotechnology
, and it is changing
the way humans interact with the
natural world.

Because all organisms are made up of the universal genetic
code (DNA), it is possible to construct organisms that are
transgenic
, meaning they contain the genes of other
organisms.

Transgenic microorganisms have revolutionized medicine,
because we can transform
bacteria

cultures

to produce
human proteins.

•

Example: People with insulin
-
dependent diabetes are now
treated with pure human insulin
produced by human genes
inserted into bacteria.

•
Steps:

•
1. Use restriction enzyme to cut
out insulin gene from human DNA

•
2. Insert human DNA into bacteria

•
3. Extract insulin from bacteria



Old school Genetic Modification

Genetically
-
Modified Organisms

•
Mammals
–

transgenic mice

–
Genes knocked out to test
tissue
-
specific disease

–
How could this be helpful?

•
EnviroPig

–

produce enzyme

–
Less costly to feed

–
Reduced phosphorous waste

–
Potential for reduced

“dead zone” in coastal waters?

•
Algal bloom in Gulf of
Mexico, emptying
from Mississippi.

•
This type of area is
considered a ‘dead
zone’ because the
massive amount of
algae deplete the
area of oxygen
leaving it completely
devoid of marine life.

Dead Zone

•
Why do you think this is occurring
here?

•
How could this be related to
EnviroPig
?

Transgenic Maize

•
Bt Corn is a variety of
corn that has been
genetically altered to
express a
Bacillus
thuringiensis

(Bt) toxin

•
This bacteria produces
a protein that can be
used as a pesticide

Transgenic Maize

•
The effects of Bt corn on non
-
target species
has been studied. Why?

•
Studies on monarch caterpillars show that
they have not suffered due to Bt corn.

•
In the US, farmers must plant non
-
Bt corn
near Bt corn. Why would this be law?

•
Pests could eventually develop resistance to Bt

•
Safety issues
–

liver, kidney, and heart toxicity
in rats tested with GM maize

Arguments against GMOs

•
GMOs spreading into non
-
GMO
food supplies

–
Wind
-
borne seeds

–
Cross
-
pollination

•
GMO
-
targeted pests developing
resistance

•
Health / nutrition of GM foods

•
Environmental impact of GM
monocultures



Arguments for GMOs

•
Reduce need for pesticides,
herbicides, fungicides, etc.

•
Reduce irrigation needs

•
Reduce temperature, pH,
climate demands

•
Increase crop yields

•
Quick results in countries that
are struggling

A
clone

is an individual or cell that is genetically identical to
it’s parental cell(s). This process was once considered
impossible, but in 1997 Scottish scientist Ian
Wilmut

successfully cloned a sheep named Dolly.

The ability to clone animals holds great promise for
medicine in the areas of stem
-
cells research and disease
control/cure. However it is also highly controversial with
regard to the possibility of human cloning.