Imagine a world in which you can create a genetic copy of your deceased pet, grow super-strains of tomatoes that preserve its ripeness long after being picked, grapevines that are resistant to fungal pests. You can even have pets with special mutations that confer viral resistance and selectively engineered pigs that might one day serve as organ donors for humans. Believe it or not, all these seemingly fictitious inventions have already been accomplished with the help of gene editing, and the list can go on and on.
Gene editing is the process to make highly specific changes in the DNA sequence of a living organism, essentially customizing its genetic makeup. The genetic manipulation process has the potential to alter any DNA sequence, whether in a bacterium, plant, animal or human being. Today, this core potential is being harnessed for a wide variety of ambitious applications, including agricultural improvement, the elimination of infectious diseases, generation of animal models and human therapeutics.
Though several approaches to genome editing have been developed, one peculiar approach that has made it easier than ever to edit DNA is CRISPR. This new form of genetic modification is simpler, faster, cheaper, and more accurate than older genome editing methods.
CRISPR-Cas9: Revolutionising the Realm of Gene Editing
CRISPR-Cas9, also known as CRISPR grabbed the headlines in 2009 with its potential to revolutionize the world of gene therapy. The arcane research tool stirred up excitement in genetics labs because it allowed genes to be edited with ease and precision.
Today, scientists can use this CRISPR technology to engineer genomes in ways barely imaginable before. From turning genes on or off to repairing genetic mutations, eliminating pathogenic DNA sequences and inserting therapeutic genes, CRISPR makes it all possible. Moreover, CRISPR works in an impressive way on a wide variety of cell types and organisms—everything from maize to mice to monkeys—allowing scientists to have a flexible, diverse, and broadly applicable engineering toolkit to tackle the biological challenges.
While Scientists are already using this gene-editing tool for modifying plants and animals, much of the excitement around this breakthrough technology is fuelled by its potential to treat or prevent human disease, especially life-threatening disorders caused by a fault in a single gene. There are thousands of serious and debilitating genetic disorders that can be passed on from one generation to the next. CRISPR-Cas9 holds the promise of treating these disorders by rewriting the corrupt DNA in patients’ cells. But it can do far more than just fixing up faulty genes. CRISPR has already been used to mutate people’s immune cells to be resistant to HIV infection or fight cancer. It is also being used to mend defective genes in human embryos to prevent babies from inheriting serious diseases.
In 2016, researchers at the Salk Institute in California applied this technique to partially restore the sight of a rat with a genetic form of blindness. They modified the cells in the rat’s eye and for the first time, the technique had been shown to work in adult mammals. Since then there has been promising advancement towards gene-editing therapies for a wide range of illnesses, from hereditary heart failure to cystic fibrosis, Huntington’s disease or even inherited metabolic problems.
The Era of Designer Baby
How would you like your baby to look like? Do you want your baby to be of moderate height or taller? What colour would you like your baby’s eyes to be? What if you can get to choose all these traits and immunity of your unborn baby? Wouldn’t be amazing to have your own customized or designer baby? This would have sounded strange two-three years back but now this concept is on the brink of becoming reality, through the advent of CRISPR-Cas9.
You strive to give your children the best possible education, clothing, food, and upbringing. So why not give them the best possible genetic code as well? CRISPR-Cas9 gives us the ability to directly manipulate that genetic blueprint and make changes in physical traits of human such as eye colour and disease risk by changing the DNA.
Long before when DNA structure was discovered, it evoked a hope about a future when it will be possible to have a custom-designed baby— equipped with superior genes for good looks, intelligence, and of course free of inherited disease. Now the concept of designer babies seems like turning into a reality.
A Chinese scientist, He Jiankui shocked the world on November 28, 2018, when he claimed that he had created the world’s first babies genetically edited with CRISPR: a set of twin girls, with a third CRISPR baby on the way. He said his goal was to try to include a trait into the babies that will help them resist possible future infection with HIV. While some are calling this a reckless approach, others are considering this as a timely and necessary next chapter in the CRISPR story. Like it or not, we are entering into the era of designer babies and there is no going back.
Where Will the Gene Editing Revolution Take Us?
There are a number of technical advances that we can expect to happen in the realm of gene editing over the coming few years. From finding more efficient ways to deliver CRISPR into cells to the adoption of precision base editing, While all these advancements paint an exciting picture of the future, we need to think carefully about where else gene editing could lead us. Although most gene editing research is focused on healing the sick, there might be people out there who are keen to disrupt the established order of biotechnology by giving healthy people an advantage.
For instance, they may attempt to use it for boosting brain power, building bigger muscles, improving sporting ability, or even creating a genetically ‘perfect’ human. We have already witnessed the risky yet life-affirming act of ex-NASA scientist Josiah Zayner, who injected his left forearm with muscle-enhancing CRISPR components during a live-streamed talk. So, having easy access to tools that alter our genomes raises big questions about its impact in the future. This is not to say that we should stop using CRISPR for treating conditions that positively affect the quality of life.
The technology is, after all, incredibly promising. We should, however, be cautious of our actions, focus on security and not get carried away in our excitement.