GMO | How it works
November 19, 2018 Marie Lödige By Marie Lödige Follow

GMO | How it works

G-M-O. You probably know what it stands for: genetically modified organism. I know there’s been a lot of controversy around it. You might think it’s unnatural, that’s it’s bad for your health. Others say that it’s actually a cool technique to make crop production more efficient. So, is it good or is it bad? Well, GMO has its pros and its cons. Maybe learning how it actually works might help you make up your own mind about it.

You know, we (if you’re human) actually have been modifying our plants and domestic animals since way back, even before the pyramids were built. Darwin called the process our ancestors used “selective breeding”.1 It sounds more complicated than it actually is. Basically:

  1. They saw traits that they liked in their plants and animals (maybe they liked the taste of sweeter strawberries, or maybe they liked dogs with big fluffy tails).
  2. They would put plants that they liked together, and animals (like dogs with big fluffy tails) together, so that their respective ‘babies’ would inherit those chosen traits1
  3. This would also slowly eliminate the least liked traits (like plants that tasted disgustingly bitter).

It’s the same today, except we “selectively breed” in labs. By using genetic engineering technologies, we’ve also opened the doors to a wider selection of traits. 

 

So how does it work?

It’s important to note that GMO does not use traditional breeding techniques (like that of our ancestors). Today, researchers actually try to transfer the DNA of one organism to another. The organisms usually are not even in the same species. Meaning it was not altered in a natural way (e.g. breeding). DNA has been transferred from one organism to another, often not the same species, to give the organism some advantages, like increased resistance to disease. 2

But similar to our ancestors, researchers pick the desirable trait from an organism. They locate the gene that carries that trait. They extract the gene, implanting it in another organism that ‘needs’ the desired trait. 3 Implanting the new DNA to alter the existing one is a small mission in itself.

Currently there are many methods of producing GMO crops. But two are used more often than others.

Method 1: The Gene Gun 3,4

The first one is a ‘gene gun’. Yes, a gene gun. And, yes, the way it’s used is as straightforward as it sounds:

  1. The plant or seed used to be literally shot with DNA through a gun (.22 calibre)7. The ammunition is a metal piece coated with DNA. The newer GMO methods now are done in a vacuum chamber (I mean, I guess that can be cool too.)
  2. First, they shoot at the DNA in plant cells in a petri dish. The DNA is then injected into the plant to see how it further develops.
  3. The plant cells in the petri dish are placed on a medium (e.g.: usually Agarose media), in which only the successful DNA changed cells survive, while terminating any cells that did not develop or mutate to have the wanted trait. This process is based on a lot of trial and error. It might take a few tries to get a successful DNA change.
  4. Once the DNA change is successful, the new DNA in the cell tries to merge with the existing DNA. But, there are still some final hurdles to create a GMO crop. For instance, sometimes two DNA sequences try to merge with the same existing sequence. This is an issue for the modification of GMOs because the cells will identify the merged DNA as “false” and will be silenced.4

Method 2: The Trojan Horse 3,5

The second method uses bacteria that alters a plant’s DNA with its own DNA by invading the plant, nature’s very own “Trojan Horse”:

  1. The bacteria are naturally wired to invade plants as a sort of “parasite”. The plant becomes the perfect host for the bacteria, but sadly, it’s not a guest that leaves. The bacteria cause diseases and stays until the plant dies.
  2. Researchers are using this invasion method by reprogramming the bacteria, attaching them with the gene traits they want, then inserting them into the plant. The bacteria act as a “Trojan Horse”, invading the plant cell and its DNA.3

What’s classified as a GMO?

The European Commission defines GMO as: “GMO means an organism, with the exception of human beings, in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination” 6 

Under these definitions, crops like corn, rapeseed oil, swede-rape, sugar beet, and cotton species are all considered GMO.
 

GMOs might seem to be the new Captain America of plants, but unlike the Super Soldier serum, we actually know what is in the GMO and how it was modified. Transparency is key, and GMO crops are either labeled as such on their packaging, or you can find information in these European Commission registers.

Let us know what you think of GMO in the comments below!

November 19, 2018 Marie Lödige By Marie Lödige Follow
November 19, 2018 Marie Lödige By Marie Lödige Follow

References

  1. From Corgis to Corn: A brief look at the long history of GMO technology Science in the News Accessed September 19, 2018
  2. Frequently asked questions on genetically modified foods Accessed September 19, 2018
  3. How to Genetically Modify a Seed, Step By Step Accessed September 19, 2018
  4. Transformation 2- Transformation Methods Gene Gun Accessed September 19, 2018
  5. Transformation 2- Transformation Methods Agrobacterium tumefaciens Accessed September 19, 2018
  6. Directive 2001/18/EC European Commission Declaration Accessed September 19, 2018
  7. Roger Segelken May 14, 1987 Biologist invent gun for shooting cells with DNA Cornell Chronicle Accessed October 17, 2018