Name: Sara
Status: Student
Grade: 9-12
Location: N/A
Country: United States
Date: April 2005
Question:
I was wondering how genetically modifying foods are developed?
Replies:
GM foods are produced by artificially introducing new genes (DNA) into the
cells of the organism to be modified. This is often done by a process called
transformation in which "naked" DNA is added to cells and the DNA is
assimilated by the transformed cells and incorporated into their
chromosomes.
Ron Baker, Ph.D.
First the gene in question has to be obtained. For example, Bt corn
contains a gene from a bacteria for a toxin that kills larva of the European
corn borer. So the gene from the bacteria had to be isolated. Then it has to
be inserted into the genome of the corn plant. There is another bacteria
called Agrobacterium that naturally inserts genes into plants. The genes it
inserts are for growths called galls. You can see galls sometimes on tree
leaves that have fallen. They look like big bumps on the leaves. Inside the
galls are the bacteria-it gives them a place to live and to obtain food from
the tree. Anyway-these bacteria naturally inject the genes for making these
galls into the plants. Genetic engineers take out the genes for making
galls, and insert the gene for the toxin from the other bacteria. Then the
Agrobacterium, now with the toxin gene, inserts the gene into the cells of
the corn plant.
Now the corn plant has genes for making toxin. But THEN to
get more plants with toxin genes, the plants have to be bred to get seeds
for plants with toxin genes. They can also do this in the lab by taking
tissue cultures of corn tissue and inserting the genes, then growing the
tissue cultures into corn plants. So, it is a very complicated process that
costs a lot of money to develop. The processes are usually patented and the
gene sequences are a trade secret.
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