CRISPR gene scissors, a revolution in life sciences and an ethical challenge: How do we respond?

CRISPR gene scissor technology is revolutionizing life sciences by enabling the elimination of inherited diseases and the manipulation of specific genes, but it is also raising controversy surrounding the dignity of life and ethical issues. We hope that technological advances and ethical concerns will be harmonized and utilized for the benefit of society.

 

People who are born with a predetermined appearance and intelligence, eliminating genetic diseases before birth. This is the world depicted in the movie Gattaca, in which advanced biotechnology allows couples to modify the genetic information of their fertilized eggs to create customized children. When the movie was released in 1997, many people thought such a world was only possible in the distant future, but now it’s likely to become a reality very soon. That’s thanks to CRISPR gene-snipping technology.
CRISPR is a term that originally referred to repetitive sequences characteristic of bacteria. Many scientists wondered why bacteria had these specific sequences. It wasn’t until 2005 that it was realized that the reason bacteria have crispers is to prevent foreign viruses from invading. Whenever a virus invades, the bacteria replicate and store a portion of that virus’s sequence. This stored sequence is useful for recognizing and attacking the virus when it invades again. The genes of this virus stored by the bacteria are what the crisper is.
So how does a crisper get rid of a virus? Actually, it’s not just the crispers that get rid of viruses, but an enzyme called ‘Cas9’. Cas9 is an enzyme whose function is to cut bases. When a virus reenters a bacterium, the bacterium uses its stored crispers to bind to complementary base pairs in the virus’s genes. Cas9 then visits the crispers, and the crispers cut the virus’s genes where they are attached. With its genes cut, the virus loses its strength and disintegrates, leaving the bacteria safe.
Crisper genetic scissors are an adaptation of this process. For example, if you want to remove a gene from a tomato that makes the tomato blunt, you create a “guide RNA” by cloning a sequence that is complementary to the sequence before and after the gene. The Cas9 enzyme is then attached to the guide RNA and inserted into the nucleus where the tomato’s genes are clustered. The guide RNA binds before and after the tomato’s ripening gene, like a bacterial crisper, and the Cas9 enzyme cuts it. This process removes the tomato’s blight gene, and the tomato will not blight over time.
Previous genetic scissors, such as Zinc finger nucleases (ZFNs) and TALENs, were modeled after restriction enzymes found in animals or plants, making them complex and expensive to produce. But because CRISPR uses RNA from bacteria, it is much simpler and cheaper to produce. And because RNA can bind complementarily to many more base pairs than restriction enzymes, CRISPR can do more delicate work than ever before. This has made it possible to produce GMO foods and treat genetically incurable diseases, among other things.
But along with technological advances, there are important ethical issues. Gene technology has been highly controversial because of its potential to touch the dignity of life, and now that genetic technology has advanced by leaps and bounds with the advent of the CRISPR scissors, we need to take a step back and look at both technology and ethics in a balanced way. Science is a double-edged sword, and we hope that by balancing technological advances with ethical considerations, the CRISPR scissors will make a beneficial contribution to society.