Last time, we covered how three different processes (artificial selection, cross-breeding, and random mutagenesis) have determined the genetics of our food for thousands of years. In the past couple decades, however, the emergence of new technology has given us the ability to genetically engineer our foods. Today, I’ll go over what exactly GMOs are, how they’re made, and how this new technology compares to the ones we’ve been using for millenia.
A GMO, or a genetically modified organism, is any organism (usually plants, animals, or bacteria) in which the genetic instructions (carried by the DNA) has been artificially modified. Most often, this includes using technology such as CRISPR (a gene editing technique) to add or remove genes. Random mutagenesis is usually not considered gene modification because it replicates a process that could occur naturally; CRISPR gene modification, however, can only take place in a laboratory. It’s not like you see genes getting modified in the wild. :) Through genetic modification, scientists can manipulate the individual genes of organisms. This allows us to introduce new genes to a species without the negative consequences associated with the earlier processes.
While artificial selection only allows us to amplify existing traits, gene modification allows us to introduce new traits to a species. Although new traits from similar species can be introduced through cross-breeding, gene modification technology doesn’t have this, so the sky's the limit! It also eliminates the potential negative effects of combining two incompatible genomes (sets of genes). Finally, gene modification improves on random mutagenesis by allowing scientists to choose exactly which genes they want to change. Because of this, the unintended and potentially harmful “off-target” mutations that occur in random mutagenesis are avoided. Accuracy, effectiveness, and efficiency is the name of the game!
Let’s return to the blue peach example from last time. All three previous methods (artificial selection, cross-breeding, and random mutagenesis) our farmer considered turned out to be ineffective for producing his blue peaches. :( In summary, artificial selection failed because there are no peaches that are even slightly blue, cross-breeding failed because the blue-color trait was not available in any similar species, and random mutagenesis would take too long and require too much work to isolate a blue peach. Gene modification, however, lets our farmer solve all these problems at once. Plenty of plants (and other organisms) produce blue colors. Using gene modification, our farmer could take the blue-color gene from a blueberry plant and add it to the peach genome. The resulting peaches would then exhibit the blue-color trait the farmer was looking for without changing any of their other features!
In this way, gene modification allows us to do more with our food sources than ever before. But how are GMOs used today? Next time, we’ll look into the various effects of GMOs, both on your body, and on the world as a whole.
Traditional breeding methods have the potential to introduce unwanted genes from the DNA donor to the new variety. Gene modification technology avoids this risk by copying over only the desired gene.
Post By: A Contributor
Cover photo credits: USDA, https://www.ams.usda.gov/rules-regulations/be/symbols
Article photo credit: Michael J Ermarth, commons.wikimedia.org/wiki/File:Methods_of_Plant_ Breeding_(8737954801).jpg
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