Recommendation of Bt Corn for Billy and Thelma
The loss in profit corn farmers suffer from European corn borers causes a great deal of
concern for farming families who want to stay in the business. We were given the task of
investigating this major issue for farmers today: should they plant Bt corn to combat European
corn borers? This question begs research in different areas. Is Bt corn safe for human
consumption? What impacts does Bt corn have on the environment?
Bt corn is genetically engineered corn, incorporating a gene from the bacterium
Bacillus
thuringiensis.
Genetically engineered plants are also called transgenic plants. Transgenic plants
are plants that contain genetic information of other organisms.
The bacterium
B. thuringiensis
produces insecticidal proteins that form crystals in the bacterial spores. These proteins are toxic
to insects such as the European corn borer. When these crystals are ingested by certain insects,
they are activated by enzymes in the insect gut and bind to specific receptors in the intestinal
tract. This causes the intestinal walls of the insect to break down, and the insect is ultimately
killed.
To make Bt corn, the gene of interest must be isolated. In this case, the gene of interest is
the crystal toxin gene from the organism
B. thuringiensis.
This gene is inserted into a bacterium
such as
Escherichia coli
using a plasmid vector. A plasmid is a circular DNA molecule that has
the ability to replicate independently of the bacterial chromosome. The bacterium with the
foreign DNA in it replicates normally, and its progeny are clones of the original plasmid-
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containing bacterium. The bacteria are then tested to see if they contain the plasmid through
growing them on a selective medium that will kill the bacteria without the plasmid. The plasmids

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- Fall '08
- Stein
- Microbiology, DNA, Bt Corn
-
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