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Prof. Markus Affolter about CRISPR/Cas9

Only a few years ago, the gene scissors CRISPR/Cas9 were discovered. It has revolutionized the scientific world, as it has never been so easy to change the genome of organisms. CRISPR has become a widely used tool in basic research. But what about applications outside basic research, how far are we allowed to go and what are the risks? 

What are the advantages of CRISPR/Cas9 compared to the previous gene technologies?
CRISPR combines many advantages. The method is simple, cheap and above all efficient and extremely precise. Furthermore, it can be used anywhere, in plants, animals, bacteria, cell culture and even in human cells.

And how does this method work?
CRISPR is a gene scissors that can be used not only to selectively edit the genome, but also to remove whole genes, insert modified DNA sequences and tag specific locations. All you need is an RNA molecule that specifically recognizes the target sequence in the genome and determines the cleavage site. The Cas9 protein then cuts the DNA at the desired location. CRISPR is sensational for research. Without this method, many experiments would take considerably longer, some would even be impossible.

What is the potential of CRISPR/Cas9?
The application spectrum of CRISPR is extremely broad and goes far beyond research. For example, CRISPR-modified mosquito populations could stop the spread of malaria or dengue fever; genetic defects could be corrected to cure people with hereditary diseases. The potential is also great in the field of plant breeding. Due to climate change, we need robust varieties that better tolerate drought and heat. CRISPR is not only much more efficient but also less risky than classical breeding methods. I personally see an enormous potential for CRISPR in the future.

Are there also any concerns or risks?
In my opinion, the application of CRISPR in basic research is safe, particularly as there are no commercial interests and release experiments. However, in particular for applications outside research, there are many concerns and risks that need to be discussed, both at the scientific and social level. Questions concerning the usefulness of gene therapy in a specific case need to be answered, as CRISPR is not error free.

Is there a debate among scientists about how far we are allowed to go?
The fast pace at which gene editing technologies continues to develop requires a close exchange between researchers, politicians and society. In response to the CRISPR-edited babies, researchers have recently called for a global moratorium and currently prohibit any human germline editing. Editing the germline carries risks, as the modifications are passed on to the offspring. This has serious consequences – not only medical, but also social, ethical and legal ones. Intervention in the human germline is currently an absolute No Go. It is neither ethically justifiable nor wise. In many countries, including Switzerland, it is prohibited by law with good reason.