This is the most exciting time in genetics since the discovery of DNA in 1953. This is mainly due to scientific breakthroughs including the ability to change DNA through a process known as gene editing.
The potential of this technology is surprising – from treating genetic diseases, modifying food crops to resisting pesticides or changes in our climate, or even bringing the dodo “back to life”, as one company says it hopes to do.
We will only be hearing more about gene editing in the future. So if you want to make sure you understand new updates, first you need to get to grips with what gene editing actually is.
Our DNA is made up of four main molecules called bases (A, T, C and G). Sequences of these four bases are grouped into genes. These genes act as the “code” for the main substances the body should make, such as proteins. Proteins are important molecules, which are essential for maintaining a healthy and functional human being.
Genes can be short, usually made of less than a hundred bases. A good example is ribosomal genes, which code for different ribosomes, molecules that help create new proteins.
Long genes are made up of millions of bases. For example, the DMD gene codes for a protein called dystrophin, which supports the structure and strength of muscle cells. DMD has over 2.2 million coins.
How does gene editing work?
Gene editing is a technology that can change DNA sequences at one or more points in the strand. Scientists can remove or change a single base or insert a new gene entirely. Gene editing can literally rewrite DNA.
There are different ways to edit genes, but the most common technique uses a technology called CRISPR-Cas9, which was first documented in a groundbreaking paper published in 2012. Cas9 is an enzyme that acts like a pair of scissors that can with them to cut DNA.
It is assisted by a strand of RNA (a DNA-like molecule, in this case created by the scientist), which guides the Cas9 enzyme to the part of the DNA the scientist wants to change and binds it to the target gene.
Depending on what the scientist is trying to achieve, they can simply remove a segment of DNA, introduce a single base change (such as changing A to G), or insert a larger sequence (such as with a new gene). When the scientist is finished, the natural DNA repair processes take the cuts together and glue them together.
What could gene editing do?
The benefits of gene editing for humanity could be significant. For example, it could be a future treatment for sickle cell disease, a genetic blood disease, by making a single fundamental change in people’s DNA. People with this disease have only one base that is mutated (from A to T). This makes the gene easier to edit compared to more complex genetic conditions such as heart disease or schizophrenia.
Scientists are also developing new techniques to insert larger portions of bases into the DNA of crops in the hope that they can create drought-resilient crops and help us adapt to climate change.
Why is gene editing controversial?
Gene editing is a controversial topic. If governments don’t work with scientists to control its use, it could become another technology that only benefits the wealthiest.
And it comes with risk.
The first case of illegal implantation of a genetically edited embryo was reported in 2019 in China, and three scientists were jailed as a result. Scientists tried to protect twin fetuses from HIV being passed on by their father.
But when other scientists read excerpts from an unpublished paper written by the DNA experiment lead about the twins, they feared that instead of introducing immunity, the researchers had probably created mutations whose consequences are still unknown.
The risks of developing designer babies are so high that it is unlikely to be legalized anytime soon. A tiny mistake can ruin a child’s health or lead to other diseases throughout their life, such as an increased risk of cancer.
The laws and regulations surrounding this technology are strict. Most countries prohibit the implantation of a genetically modified human embryo in any way. However, as the 2019 example shows, laws can be broken.
Gene editing has its advantages. It has the potential to cure genetic disease and create drought resistant crops. But scientists need to work closely with lawmakers and policy makers to ensure that the technology can be used for the benefit of humanity while minimizing the risks.
The fact that a private company recently announced plans to try to bring back the dodo shows how important it is that international gene editing laws keep up with corporate ambitions.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Gavin Bowen-Metcalf does not work for, consult with, share in or be funded by any company or organization that would benefit from this article, and does not disclosed any relevant connections beyond their academic appointment.