Breaking Down the Science of Bt Eggplants and GMOs by Garrick Bercero


Our guest writer for this article is Garrick Bercero, currently an Education Consultant for The Mind Museum and a Multimedia Producer for the Filipino Freethinkers.

    The Supreme Court has effectively stopped all field testing of genetically modified organisms. With its decision on a case regarding research on Bt eggplant, they cited the precautionary principle, stating, "lack of scientific certainty is no reason for inaction at the risk of potentially serious or irreversible harm to the environment. 

     While some may find this an environmentalist victory, there is much needed clarity on this matter by way of basic molecular biology. The technology behind Bt eggplant is much less "Frankenstein"and a lot more like "highly accurate surgery on the molecular level."

[Photo credit: Arif Hossain, from Cornell Alliance for Science website]

     The "Bt" part of Bt eggplant, or Bt corn, or any other pairing refers to Bacillus thuringiensis. This is a bacterial species that produces a particular protein (called Cry, for its crystalline structure) that kills pests such as insect larvae. These larvae eat through the crops and largely invisible until it's too late, as they eat the insides of the plants. They can even eradicate entire fields. 

     Despite the Supreme Court's doubts about Bt technology, the scientific community does not share this lack of confidence. This protein has no effect on human metabolism, making it ideal as a method of only targeting pests without risking human health, unlike standard pesticides. It has been in use for the past forty years with no adverse human reactions due to the Cry protein.

     Humans have long been genetically modifying organisms. Most of the food we eat today would not exist without the old-fashioned form of GMOs: breeding. By breeding plants and animals, humans pick traits that they desire from one generation and try to produce more of it. Farmers pick the largest and tastiest fruits and the healthiest and fattest livestock. They make sure they reproduce and pass on their genes. 

British cow breeds displayed in an animal breeding
contest in France in 1855. 

     When normal reproduction happens, it is more like a shotgun method of trying to create copies of desirable genes. For example, if we want a cow that produces more milk, what we are really looking for are the specific genes that regulate milk production. We want the versions of the genes that make more milk!

     So how do we find these gene versions? In traditional breeding, we find the cows that produce the most milk, breed them with bulls, and hope that the offspring will carry the gene. This also risks that we get a calf that has traits that we don't like, since we are getting a random sampling of the genes of the parents. But, with modern genetic techniques, we can hunt the gene directly and insert that into a cow embryo. 

     More than that, modern genetic modification techniques allow us to get genes from one species and place it in another. Perhaps the most critical GMO created by a laboratory are insulin-producing microorganisms. 

[Photo credit: U.S. National Library of Medicine website]

     Before, pig pancreases needed to be harvested at massive quantities to produce an inferior non-human insulin. But, with the advent of new genetic techniques, scientists were able to transfer human genes into bacteria and yeast to make insulin. This technology has saved the lives of diabetics the world over, and Bt plants are simply another facet of this blossoming field of research. 

     Yes, it is always important to make sure that our food is safe. Perhaps the forty year history of Bt technology would attest to its safety. But, it does not help in learning more about the safety of Bt eggplants to ban field testing outright. 



No comments:

Post a Comment