QI am an agricultural economist writing a book chapter on GMOs. I tried to explain how genetic modification takes place with the statement, "A GMO is an organism where the genes from another organism (usually a bacteria) are deliberately inserted into the

I am an agricultural economist writing a book chapter on GMOs. I tried to explain how genetic modification takes place with the statement, "A GMO is an organism where the genes from another organism (usually a bacteria) are deliberately inserted into the organism in hopes that it will exhibit certain desirable traits, like creating its own pesticide or being resistance to a certain herbicide." When I asked a scientist to review this statement he replied, "This is incorrect. A GM organism is one whose development involved the in vitro manipulation of DNA. This is not a petty little point. RNA can be used, no new genes may be present, and we can now make mutants that have specifically mutated genes in them but no new added DNA. Science has moved on so far that most legal definitions of GM are no longer adequate." I'm hoping you can help me understand his statement. How can a new gene enter a DNA sequence (through human manipulation) if it was not taking from some other organism's DNA sequence?

AExpert Answer

Thank you for your important question. The definition of a “GMO” or a transgenic organism refers to an organism containing a gene inserted by man. This is quite evident when one reviews the criteria for release of these organisms as defined by the Joint Food Standards Program of the Food and Agriculture Organization of the United Nations and the World Health Organization, as well as Codex Alimentarius Commission (reviewed in Steiner, H-Y, Halpin C., Jez J., Kough J., Parrott W and , Hannah, LC. 2013 Evaluating the Potential for Adverse Interactions within Genetically Engineered Breeding Stacks. Plant Physiol, 161: 1587-1594.)

The gene need not be from another organism or from a bacterium. For example, our lab modifies corn genes and puts them back into corn and this is still considered genetically modified. Part of the “approval” process involves a determination of the position of the new insertion and some assurance that this new insertion site is not in a gene important for the plant or for food safety. Also, we use sequences from a bacterium for the insertion process that do not normally occur in maize (although they are now found in other approved maize transgenic events).

The point that the distinction between transgenic and non-transgenic is murky (and in some cases nonsensical) is quite valid. For example, the bacterial sequences that insert the genes into plants to make transgenics mentioned above do this naturally in nature and yet this is not regulated when it occurs in nature. Also, there exists much genetic variation in nature. Two corn inbred chosen at random are more distantly related than man is to the chimpanzee, yet we are not really concerned about how this “natural” variation affects food safety.

I look forward to the day when this issue of classification and approval is based more on science than it is on politics and fear mongering.

Posted on July 21, 2017
GMOs aren't really added directly to the meat, beef.  However, beef cattle may consume feed that comes from a genetically modified plant. All beef cattle begin their lives on a farm or ranch, grazing pasture or grass - none of which is considered a GMO. For many cows this will be their sole source of feed for their lifetime. Some cattle receive rations of grain, which may contain corn or soybeans, both of which have genetically modified hybrids and varieties. ... Read More
Posted on March 28, 2017
Thanks for the question, which I will address in two ways here.   1. What are three ways that organisms are modified by scientists? Here I will focus only on plants.   a. Agrobacterium: Agrobacterium tumefaciens (Agro) is a naturally occurring soil organism that causes a disease in plants called crown gall disease. In the late 1970s, Mary-Dell Chilton discovered that Agro actually transfers genes (DNA) from the Agro to the plant cell, where it becomes integrated into the plant... Read More
Posted on March 2, 2017
First of all, to clarify – hybridization is part of conventional breeding and conventional breeding uses hybridization to create new combinations of genes from parent varieties. For example, a disease-resistant wheat variety may be hybridized to a variety that makes flour better suited for making whole wheat bread. This is a common goal of most conventional breeding programs. It typically involves taking pollen from one parent and using it to fertilize another parent. The... Read More