CRISPR’s capabilities have been expanded once again, this time to be used to increase the amount of healthy fats in soybeans.
Let’s skip right into the details for once without any backstory.
To The Research!
Researchers at the Institute for Basic Science (IBS) in South Korea have been working on their own variant of CRISPR that doesn’t utilize the Cas9 system. Instead, they have introduced the Cpf1 system that works quite a bit differently.
It was first obtained from the Prevoltella genus of gut bacteria and the Francisella genus known primarily for causing severe tularemia infections. And the way it acts is far off from its Cas9 cousin system in Streptococcus pyrogene.
This system has been designed to recognize and cut specific parts of a genome that were pre-designed into it. So far, so much the same. Cpf1 proteins and targeted CRISPR RNA were introduced into the cellular systems of soybeans and tobacco plants, as a control.
Protoplast cells were used, which have no cell wall, to ensure access by the CRISPR components. The experiment wasn’t a test of its ability to get into cells, after all, and they wanted to confirm that it worked properly once inside.
An Organic Chemistry Lesson
The CRISPR guide RNAs used were designed to not match any of the sequences in the soybean genome, with at least 3 mismatches of difference, so as not to cause a conflict with the activating proteins.
Once inside, the CRISPR-Cpf1 complex was used to cut both strands of both genes for FAD2. The purpose of these genes is simple, oil conversion. It takes oleic acid, the healthier one (maybe) that is the primary component of olive oil, and “unsaturates” it by adding a double bond to the carbon structure. This converts it into linoleic acid.
And while the latter is still an essential fatty acid, oleic acid is preferred for soybean output in regards to health benefits. So, while the health benefits of each are still heavily debated and there is an argument on which is better for you, soybeans are wanted as a source for oleic acid, while other crops are used for linoleic acid consumption.
Anyways, back to how Cpf1 does this. Unlike Cas9 that’s used to remove and insert genes into the genome, Cpf1 takes a different tactic. It causes mutations at the cutting site. These mutations are most commonly point deletions, where one nucleotide is removed. This causes the overall gene to stop functioning while not interfering with the rest of the genome.
This was confirmed by the scientists when looking into the effects of its use and found that no off-site mutations or changes occurred.
The most important component of this new CRISPR tool is that it doesn’t require any direct DNA changes. It is “DNA-free” as the researchers put it and is a method that is only genetic modification in the loosest sense.
It has the same effect as any number of mutagenic chemicals used in other breeding methods, but it has the exact precision that is expected from biotechnology. This means it has a incredibly low likelihood of causing negative unknown outcomes like non-biotech options.
Add It To The Toolbelt
Another important use is that Cpf1 is smaller than the Cas9 system by about 60 nucleotides, meaning it is able to be used in more situations than its predecessor can. But, as noted, it does have the limitation of not being able to actually add or take out genes wholesale.
This means that CRISPR-Cpf1 will find its niche exclusively in turning off gene function in organisms. Though this is still an incredibly significant role regardless.
With both Cas9 and Cpf1, along with other new versions of CRISPR being worked on, the abilities of biotechnology continue to grow day after day.
Photo CCs: Soybean Oil, Meal and Beans from Wikimedia Commons