Blurring Lines of Genetic Modification

One comment I’ve heard frequently in discussions about transgenic plants is how the description “genetically modified” is a misnomer given how much we’ve modified the genetics through traditional breeding. Some proposed changes to how the EPA may regulate the use of this technology serve as a good example of how the distinction between old and new methods of modification may not be that important.

These proposed changes would relax the restrictions on some classes of crops that have been modified. One group called “cisgenic” modification would involve the transfer of gene between plants that can naturally interbreed. The example that introduced this concept was the American chestnut which is sensitive to a blight, while the related Chinese chestnut has developed resistance. It may be possible to cross these two plants to provide resistance in the American plants, but this would involve all the messiness of trying to get the right chromosomes into the new plants and hoping other undesirable traits don’t come along for the ride. On the other hand if we knew exactly which genes are responsible we could isolate them and transfer the genes, without having to worry about other genes interacting in unwanted or unexpected ways. According to the article, Charles Maynard and his group at the State University of New York is possibly close to identifying the genes responsible, getting us closer to being able to use the technology in such a way.

Alternatively, intragenic (inside the gene) modifications can be done that remove parts of DNA to change expression of traits, but wouldn’t need to have any new DNA being inserted.

However modifying the DNA in a lab instead of the field by crosses would mean these crops would have to go through the additional regulatory processes as transgenic organisms that have foreign DNA inserted into the genome. The proposed changes would allow cisgenic and possibly intragenic modification to bypass some of the requirements that transgenic crops have to go through. Not too surprisingly this has met resistance from those who think these kinds of plants should be more regulated rather than less. But it has also been opposed by people in support transgenic crops who think the change would create an artificial distinction based on the source of a gene, which really says very little about any actual effects of the changes that have been made. That this is an issue is a good demonstration of how the current regulatory system seems more focused on technology being used rather than actual properties of these plants.


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