Genetically
Engineered Corn and Its Effect Sol Lee
Genetically engineered corn, commonly
referred to as Bt corn, is engineered to target insect
pests such as the European corn borer. In the
The
process in which Bt corn is created, is by inserting a
gene from the bacteria Bacillus thuringiensis into
the corn cell genome. The Bacillus thuringiensis has
two sections of toxins: cytolysins (Cyt) and crystal delta- endotoxins
(Cry). The crystal delta- endotoxins targets the
intended insects and binds onto receptors, on the membranes of epithelials cells of the mid gut, causing rupture of these
cells. Any target pest insect that feeds on a genetically modified Bt corn, would die, as the crystal delta- endotoxins would rupture their gut.
The
concern over this killing process of Bt corn, is the
unintended risks of the gene, on non – target insects. An
The
Royer research team calculated the quantity of Bt
plant parts, pollen, leaves, and cobs, that entered 12 streams near a heavily
farmed
This
wide spread of Bt corn byproducts causes a huge dilemma, as field data
collected by the team show that, caddisflies, and
important food source for other organisms in the food web, are eating the Bt
plant parts. The caddisflies are genetic relatives of
the targeted Bt pests. The research team conducted
laboratory trials, and had one group of caddisfly eat
leaves from Bt corn and had another group of caddisfly eat non- Bt corn. The researchers established
that the caddisflies that ate Bt
corn grew less than half of the caddisflies that ate
non- Bt corn litter. Another strain of caddisfly was
tested, and they had a shorter life span when exposed to the Bt
corn pollen.
The
wide spreading impact zone of the Bt corn byproducts
causes a huge problem for the aquatic ecosystems affected. Caddisfly
are a major food source for superior organisms such as fish and amphibians. If
the Bt corn byproducts were to spread even further and
increase in concentration, caddisflies populations
could shrink, as the laboratory trials indicate. This would cause a domino effect
as the predators relying on the caddisfly would have
less food and then their own population would shrink and so on. This shrink in
populations of fish, could then in turn hurt human populations. The Bt corn could have a serious affect on aquatic, and other
ecosystems, their food chains, webs, and habitat.
Genetically
engineered corn could have a serious risk of harming not only aquatic
ecosystems, but humans as well. This problem must be further researched, and
dealt with. Genetically engineered corn has its fair share of risks and
benefits, but in this case the negatives may outbalance the positives, and
caution must be taken, whether through new experiments, or by founding of new
genetic strains.
The Bt corn
pollen, leaves, cobs, and detritus was found to travel down into streams and
rivers, attacking both target corn borers, and non- target caddisflies.
Bt corn percentages
among corn acres is steadily on the rise, averaging at approximately 40% now in
2008. Adoption of other genetically engineered crops like Ht soybeans, are also
steadily on the rise, in the
References:
1.
2. Siegfried,
B.D. and Rice, M.E and Pilcher, C.D. and Onstad, D.W. and Mason, C.E. and Lewis, L.C. and Landis,
D.A. and Keaster, A.J. and Huang, F. and Higgins,
R.A. and Haas, M.J. and Gray, M.E. and Giles, K.L. and Foster, J.E. and Davis,
P.M. and Calvin, D.D. and Buschman, L.L. and Bolin,
P.C. and Barry, B.D. and Andow, D.A. and Alstad, D.N. “Bt Corn & European Corn Borer.”
3. Hall,
Hardy. “BT CORN: IS IT WORTH THE RISK?.” The Science Creative Quarterly
Issue 3. 08 August 2005 22 February 2008 http://www.scq.ubc.ca/bt-corn-is-it-worth-the-risk/