So, I think we’ve all seen this type of image from anti-GMO activists:
The irony is that this is so completely divorced from what one actually does to modify a tomato, or indeed any plant, that it only serves to polarize. Also, it allows people who study genetics to immediately identify someone with absolutely no knowledge in the area of genetics, or genetic engineering.
So how is it really done?
Well, there are many ways. One of the most common, and classic, is using Agrobacterium tumefaciens. This bacteria has the special ability to take a certain part of its DNA (TI plasmid) and insert it into plants, and have this same DNA gain access to the nucleus. It doesn’t work on every species or family, but it works on quite a few, including Solanum (which includes potatoes and tomatoes). When used, it is applied primarily to female reproductive cells, allowing the plants to pass it onto the next generation.
The most famous way is probably using a “gene gun,” which also leads to a random incorporation of the added DNA. Remember that prior to ever being reproduced, all GM crops are analysed on a genetic level to figure out not only how many copies of the added gene are there (they only take clones that have a single copy), but also to determine in which clones there was no interruption of normal genes.
Similar to when using the gene gun, we can also otherwise modify “baby” cells and then encourage them to turn into plants that we can breed. We don’t need to use a gene gun to do this, we can actually do this using electroporation. This is where we use an electrical pulse to allow the desired DNA to enter the cell, this is most famously used with bacteria but it also works on plant and even animal cells.
The initial gene insertion pretty much always carries a selection or screening marker, to help scientists know which of the resulting colonies they want to investigate and multiply. This can take the form of antibiotic resistance or of an enzyme allowing a specific visible metabolic reaction. Without this, scientists wouldn’t know which plant/animal cells to continue working on: it verifies the existence of the inserted material.
The next step is an obligatory step in modern GE: removing the selection marker from the transgenic organism, leaving simply the desired inserted sequence at a position that doesn’t interrupt another gene. Scientists enable this by including restriction sites around the selection marker, which allows this alone to be removed through a Cre/lox or FLP-FRT type system.
Now, after the insert has been verified, the selection marker removed, and the presence of the desired gene has been verified again (using PCR), they are ready to start breeding the clones and testing for health and environmental impact. Unlike the crops resulting from random mutations used in both conventional and organic, the mutations and health consequences of a GM crop have to be very thoroughly defined and tested.
On average, it costs over $130,000,000 and 13 years to bring a GM crop to market, which is over a hundred million more dollars and 8 years longer than it takes to introduce a new organic or conventional crop created from blasting the seeds with radiation.
Since GM does not work with completely random mutations, where do their genetic changes come from? Well, there are actually a LOT of ways to modify proteins, but the general process looks something like this:
The fact is that if you thought that GMOs were untested, and created using “hormones” and needles whatsoever, you have been duped. There is a conspiracy relating to GMOs, but it isn’t about poisoning you or even “owning” the food supply (literally all crops can be patented, including non-GM), but it has to do with distracting consumers from understanding where the different seeds come from.