More unresolved GMO issues

Most of the debate about GMOs has focused on transgenic crops in which a gene from one species is inserted into the DNA of another species. With herbicide-tolerant crops, a gene from a plant that is resistant to the desired herbicide is inserted into the genome of a crop like corn or cotton that normally is killed when sprayed with the given herbicide. Similarly, scientists have inserted a gene that induces the production of the toxin produced by the bacterium Bacillus thuringiensis into a corn plant. The corn plant then produces the toxin and kills European corn borer caterpillars, reducing the need for spraying the plant with an insecticide that would be used to kill the caterpillars, saving the farmer a field pass and the cost of the insecticide. In recent years, as scientists have increased their knowledge of the function of various genes in a given species, they have developed the technology (CRISPR) needed to edit a gene to express a desired trait. In this case a “foreign” gene is not inserted into the organism’s genome, rather the organism’s own genome is slightly modified. At present transgenic organisms are subject to government regulation while gene-editing using CRISPR technologies is not, because the organism does not contain any “foreign” DNA. For a more thorough summary of the technologies and their risks, readers can download “Genetically Engineered Crops: Experiences and Prospects” by the National Academies Press (http://tinyurl.com/j5kvhg7). In the current debate, some have argued that these technologies are little different from conventional breeding which uses a less precise means of selecting for preferred genetic traits in all domesticated crops.