When I started writing for HerCampus, I told myself that I wanted to write articles about science for the non-science-y. As a science student, I’ve always loved explaining ideas and concepts to my friends in other fields and watch their faces light up when they understand. To me, science is so remarkable, and unfortunately, I found that the more I dive deeper into this world of research and innovation, the more it becomes an elitist club of people who use jargon. Today I am here to explain to you a concept that many of us may have heard of but never really understood. In fact, it was what got me hooked on science in the first place: gene editing.
Genes: What is that really?
You think you know genes, right? I bet your answer is something along the lines of “It’s your DNA and it’s what gives you certain traits” which is true, but there’s so much more.
You are right, genes are made up of DNA. A gene is essentially a set of instructions that makes proteins. However, not all genes code for proteins. In fact, only about 1% of human DNA actually codes for proteins. These non-coding genes are made up of noncoding DNA, and they’re useful for regulating gene activity (like if a gene is turned on or off) by serving as a spot of DNA where certain proteins called transcription factors will stick to that area and dictate if the gene is turned on (if the DNA instructions will be read to make proteins) or if it will be off (the instructions will not be read and no protein will be made). An example of a gene that isn’t expressed (turned on) is the gene that codes for a protein that breaks down lactose, it’s what makes people lactose intolerant. Humans have between 20,000 to 25,000 genes that can be either really small stretches or long stretches of DNA.
Every person has two copies of each gene; one from your mom, and the other from your dad. Most genes are the same between everyone, but they contain small differences in the bases that makes up your DNA. It’s because of these small base differences that give us different traits.
But what are proteins?
A lot of scientists struggle with this question, not because it’s hard or controversial but simply because the question is so vague. Essentially, a protein is a molecule made up of thousands of these tiny structures called amino acids. You’ve probably heard of amino acids, people talk about them being in your food and your skincare. There are 20 amino acids, and they stick together in various orders and sequences to make long chains. The sequence of these amino acid chains determines a protein’s 3D structure and the protein’s function in your body. Some typical protein functions in your body include transporters, which transport other molecules throughout your body (like blood cells), messengers, which relay bodily signals to other parts of your body (like hormones), or enzymes, which perform chemical reactions in your body (like the protein that breaks down lactose that I was talking about earlier).
So to recap: DNA is made up of bases and stretches of DNA make genes. Genes are instructions that code for proteins. But how does it code for proteins, you might ask? Well, when reading this set of instructions, every 3 bases dictate what amino acid will be added to the chain. Once the chain is complete, it folds in a 3D form and gets to work right away.
As I’ve said, the order of these amino acids in the chain dictates the protein’s function, and if this order changes, it’s possible that the protein’s function changes. If there is a change in the amino acid produced, this creates mutations in your protein.
What is gene editing?
Now that you’ve learned more than the average person on genes, you’re ready for the big stuff. Gene editing is exactly what the name entails, it’s a series of techniques that allow scientists to make changes to the genetic code. DNA can be altered to allow changes to your DNA which can do everything from cure diseases to deciding what eye colour your baby will have.
How does it work?
One of the ways scientists do this is through a tool called CRISPR Cas (I’m not gonna bother explaining the acronym it’s just a bunch of jargon anyway, and most scientists don’t even know what it stands for off the top of their head). As simply as I can put it, scientists make a short DNA sequence in the lab (which is called a guide DNA) that binds to a specific DNA sequence in a given organism. This guide DNA stuck to your regular DNA flags over a Cas9 protein to come over and cut that specific region of your regular DNA. Cells have a DNA repair system in place if ever the DNA is cut or damaged and so scientists utilize this system. They can also insert specific DNA sequences and the cell’s DNA repair system inserts that specific sequence where the DNA was broken.
So why aren’t doctors using this to cure diseases?
Scientists are kind of still in this phase of assessing if this is safe and effective for humans. And even if it is safe and effective, policies need to be put in place to determine just how and when this can be used. Currently, researchers are exploring its ability on just about every genetic disease imaginable.
There’s a lot of ethical concerns surrounding this. Sure, there’s a possibility of curing diseases but there’s a greater possibility with this. If these changes are performed on germ cells (sperm or egg cells) or embryo genes, the changes made to the DNA can be passed down into the next generations. This presents a problem for people who believe that it may not be okay to play with traits like athletic ability or musical talent (which yes, there are studies that prove there may be a genetic link). If you’re interested, the internet is full of debates on this.
What is in store for the future?
Right now, scientists are fascinated with finding the next better and more accurate versions of CRISPR. The big problem CRISPR has right now is that scientists can’t really be sure of what change will happen. Scientists are currently looking at base-editing methods, which are just ways that an enzyme can just come to a specific problem base in the DNA and chemically change it to something that would give the desired outcome.
So there you have it, you know all about how scientists plan to revolutionize the world now. In fact, you just received a cheap and free version of a 3rd and 4th year uOttawa science course in one article. Hopefully, you expanded your scientific knowledge just a little bit more and feel ready to impress every average joe (or even a scientist) that you come across.