Download Genetically Modified Organisms (GMOs)

Genetically Modified
Organisms (GMOs)
Any microorganism, plant or animal that
has purposely had its genome altered
using genetic engineering technology
Traditional Genetic Modification
• Also called Selective Breeding
• Farmers would always save the best seeds
(bigger, sweeter or more resistant to disease,
etc) from their crops to plant for next year.
• As a result each year the farmer got slightly
better crops. Change was slight but over
many generations the change was
significant.
For example…..
• Balsas teosinte, a wild
grass typically found
in Mexico, was
modified into…
drum roll please……
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Modern Corn
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Transgenic Manipulation
• One or more genes are artificially
inserted into the DNA of the plant’s
chromosomes.
• The gene can come from the same type
of plant or even another type of
organism
Bt Crops
• Plants with the Bt sequence of genes
can produce proteins that protect them
from various insects such as European
corn borer, southwester corn borer,
tobacco budworm and Colorado potato
beetle.
Let’s Engineer…..
• Take toxin from BT DNA and combine with a
vector (What is a vector?)
• Short piece of DNA capable of replicating on
its own when inside a bacterial cell.
• Now another gene which will make the plants
resistant to a herbicide is added.
• The vector, which incorporates the Bt gene, is
now placed into a bacterium cell.
Agrobacterium
• Causes disease in plants.
• Has the ability to transfer a portion of
it DNA into plant cells
• Once inside a plant cell, its DNA will
be incorporated into the DNA of one of
the plant’s chromosomes.
Grow the bacterium
• By adding it to a growth medium
• Each time the bacterium divides, so do
the vectors within
• Before the blink of an eye you have
millions of copies of the bacterium and
of the vector that contains the Bt gene
Now for the plant cells….
• Add small pieces of whatever plant you want
to modify (e.g. tomato, corn) to the
Agrobacteria
• The DNA of the bacteria enters the plant’s
cells and the cells’ nuclei
• The vector’s DNA (which includes the Bt
and herbicide resistant gene) becomes
integrated with the plant cells’ DNA
Grow the plant cells
• By placing the cells into the growth
medium for plants
• In the growth medium, the plant cells
multiply and form stems, roots and
leaves
Here comes the herbicide
• Spray the plants with a herbicide and
ONLY the cells with the herbicide
resistant gene survive
• Plants are transferred to a growth
chamber and the plants are allowed to
mature
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.