What is gene editing and how does it work?

Gene editing enables scientists to alter the sequence of genes by adding, replacing, or removing certain DNA segments.

Let’s start by talking about genes. As we previously see when describing the central dogma of molecular biology, genes are sections of the long DNA molecules called up inside each cell of every living thing, from microorganisms and insects to plants and animals, including humans. 

The whole DNA makes up the genome, which can be seen as the instructions manual for an organism. These instructions can occasionally contain errors, called mutations, which can lead to issues. Faulty genes can cause serious diseases and pass them down through descendants (hereditary diseases). In this post, we will see how these errors can be corrected.

Gene or genome editing

Humanity has a long history of figuring out ways of modifying genes. We have been crossbreeding plants to make them better to eat for thousands of years. But with gene editing, we’ve made a great leap forward. Compared to earlier techniques, this new technology's application is faster, simpler, and more affordable while yet offering enormous benefits. In a nutshell, it works by identifying and then cutting pieces of DNA. 

Between the early 2000s and mid-2010s, Zinc-finger nucleases (ZFNs) and transcription-activator–like effector nucleases (TALENs) - two artificial genome-manipulating enzymes - had attracted a lot of interest in the genome editing community. Starting in 2012, the CRISPR/Cas system turned into a revolutionary molecular tool for DNA and RNA “tailoring”. 

The CRISPR/Cas technology involves using a component known as CRISPR to pinpoint the precise DNA sequence within the gene to be changed. Then an enzyme called Cas9 snips through the DNA changing it or allowing it to be replaced by another structure of DNA that is introduced at the same time. This can either replace a faulty gene with a healthy one or change a gene to make it behave differently. The methods are like a finder replacement for the genetic instructions manual. Gene editing has the power to significantly modify our existence by making these minute alterations to our DNA. You can find extended information on DNA editing with this technology here.

Gene editing implications

Gene editing is already transforming genetic research. But it's critical that we balance the potential advantages with any potential drawbacks at this early stage of such a potent technology. Let's start with the positive. 

Human health can be dramatically improved through gene editing. For instance, in 2015, leukemia in a baby girl was cured by scientists using genome editing techniques. In the future, we could be able to correct the gene mutations that make some people more susceptible to developing cancer, provide new HIV medicines, or modify the genes that lead to genetic disorders. In the plant world, it can make crops more nutritious, disease-resistant, and able to grow in challenging environments. By editing animals’ genes, we could help them to resist diseases. To prevent mosquitos from carrying and transmitting malaria, researchers are actively working to modify their genomes. 

Therefore, genome editing holds enormous promise for good. However, what about the drawbacks? Early human embryos could be genetically modified to change traits like eye color that have no impact on health. This increases the possibility of designer babies. A change in an embryo's DNA would have an impact on both the child and their offspring. These same techniques can be used to create designer pets, and to develop more virulent microbial diseases. So alongside the many benefits of genome editing, there are some ethical and societal issues to take into account. The moment has come to discuss how to use technology, regulate it, prevent inappropriate applications, and realize its potential to offer game-changing solutions to some of the largest problems facing the globe.

By Miriam Martínez

Miriam is a Human Biologist expert in neuropharmacology. After a master’s degree in Pharmaceutical and Biotech Industry, she obtained her PhD in Biomedicine from Pompeu Fabra University (Barcelona). During her doctorate, she focused her research on the behavioral analysis of animal models for neurophenotypical characterization. Since then, she has been working in the healthcare marketing and publicity sector, where she has contributed to developing marketing campaigns for several pharmaceutical brands. In 2021, she joined ZeClinics with a branding and marketing strategy focus.