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Q:
I just saw your TED talk on GMOs and have a question: If you developed a hybrid plant by the "normal" vertical exchange of genes - say a hybrid tomato - would some of the negative effects of GMOs such as rogue proteins and horizontal gene transfer to bacteria be evident for these hybrids? Thank You.
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A:Expert Answer

There are a great many myths about GMOs on the web.  Two of the latest myths are the alleged threats of “rogue proteins and of horizontal gene transfer.” The "term rogue protein" invokes all manners of unease, but there is virtually zero evidence of such damaging proteins in the commercial GM crops.  There are several reasons for this.  First, when any eukaryotic cell has a misshaped, or “rogue,” protein, there is a system called ubiquination that tags the dysfunctional protein.  Then systems within all eukaryotic cells recognize the tagged faulty protein and destroy it.  In this way, misshaped or truncated proteins that will not function properly are removed from the cytoplasm before they can cause harm to the cell.

 

The notion that rogue proteins are made in GM crops is tested for.  Southern blots (which detect number of inserted gene constructs), northern blots (which detect number and size of inserted gene RNA transcripts) and western blots (which detect number and size of engineered protein products) all measure the extent of engineered DNA, RNA and protein in all GE crops as part of the regular evaluation process before commercialization is permitted.  Along with the following testing:

 

  • Principles of Risk Assessment (4 subcategories)
  • Molecular Characterization (2 subcategories)
  • Comparative Assessment (5 subcategories)
  • Toxicological Assessment (5 subcategories)
  • Allergenicity Assessment (3 subcategories)
  • Nutritional Assessment (2 subcategories)

 

You can read about the extent of GE crop/food testing done by internationally agreed protocols here:

 

 

You can read a review of animal feeding trial evaluation of GE crops here:

Safety and nutritional assessment of GM plants and derived food and feed: The role of animal feeding trials.

 

Together, these tests, which represent 10 to 50 times the testing done on crops from other breeding methods, and the safety evaluation of all GE crops are considered adequate by world food safety and toxicology experts. 

 

The idea that only GE crops contribute to the movement of genes is another of the widely held myths.  In fact, the more we look, the more science finds examples of gene movement between species.  It is clear that horizontal gene transfer (HGT, also called lateral gene transfer) is widely found in nature and is not a unique risk for GE crops and food.  Therefore, to answer your question, yes, HGT happens with non-GM crops, such as hybrid plants, as well.

 

The safety of GE crops and food is best stated by the American Association for the Advancement of Science 2012 statement: “Moreover, the AAAS Board said, the World Health Organization, the American Medical Association, the U.S. National Academy of Sciences, the British Royal Society and every other respected organization that has examined the evidence has come to the same conclusion: consuming foods containing ingredients derived from GM crops is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques.” 

Topic: Safety, Health, and Nutrition  3 Comments | Add Comment