A CRISPR World

Every once in a while, scientists make a phenomenal discovery that truly transforms their field.  For biomedical research (and therefore for the world, as I like to think), no recent discovery has spread as fast and as widely as the CRISPR/Cas9 method of gene editing (making precise changes to specific regions of DNA). This technique is currently so popular that it has scientists and non-scientists alike genuinely interested in its prospects in terms of improving research and healthcare. Being the resident family biologist, I often get asked what all this “crispy” talk is about (note to my dear brother: the joke is only funny once!). Here is my standard introduction to this future Nobel prize-winning technology:

For several decades, scientists have studied the function of specific regions of DNA by causing damage to those regions and examining the effects of the damage on individual cells, organs or the whole organism. While methods used for these kinds of experiments have been improving steadily, the discovery of the CRISPR/Cas9 system is a huge leap forward. The CRISPR/Cas9 system was first identified as a natural method by which some bacteria protect themselves from other microorganism, such as viruses, which attack by injecting their DNA into the bacteria. Without getting too technical, there are two parts to this system: the CRISPR (clustered, regularly interspaced short palindromic repeats) complex, which can recognize a specific sequence in the foreign DNA and bind to it, and Cas9 (CRISPR-associated protein 9), a protein which destroys the foreign DNA by cutting it up, keeping the bacteria safe.

In the lab, scientists can modify this system to target and cut specific regions of DNA in any organism. When a cell’s own DNA is cut, though, its natural response is to try to fix the damage. However, the ways by which these cuts are fixed are not perfect, and mistakes are often made where bits of DNA are added or left out of the fix.  This disrupts the function of the targeted region of DNA, and researchers can then observe the result of these mistakes to learn more about the function of the affected region.

Why all the fuss about CRISPR, you ask? From first-hand experience, CRISPR is significantly more accurate and efficient than previous techniques. To illustrate, the difference between some existing methods and CRISPR is like the difference between asking a six-year-old to find and correct a single spelling mistake in an encyclopedia, and giving the same task to an English professor. Another significant advantage of this system is its adaptability. CRISPR success stories have been reported for organisms ranging from fungi to fish, which is why scientists are universally excited about it. Moreover, the components of the system are cheap, easy to get, and easy to use, making it a viable option for almost any lab. Being able to disrupt a region of DNA is great, but the system has further been modified  so that researchers can also increase, decrease or even change a gene’s function almost at will, and herein lies the immense power of the CRISPR/Cas9 system.

CRISPR/Cas9 technology is so enticing, however, that this sometimes sends scientists down its path when other methods may actually be better for a specific experiment. Sadly, if journal and grant reviewers want to see CRISPR, then CRISPR you must use. Also, the CRISPR system is not flawless, and there are concerns about damage being caused to other sections of DNA that were not targeted.  Moreover, as everyone jumps onto the CRISPR bandwagon, overenthusiasm to publish findings whether for or against the use of CRISPR technology makes room for some sloppy science.

If you’re not in biomedical research, you’ve probably still heard about how scientists are going to use CRISPR to make designer babies and genetically modified foods that will either save or kill us all. How true are these claims? Well, CRISPR does make gene editing much easier, meaning that some things that were not feasible before are now possible. For example, some success has already been reported in using CRISPR technology together with IVF (in vitro fertilization) to fix a heritable disease in human embryos. This application of CRISPR technology is still in its preliminary stages, and we cannot expect that it will bring about an end to all genetic diseases as CRISPR is most useful under specific circumstances. However, for potential parents who are carriers of, or even affected by a heritable genetic disease, this technology  brings to them the hope of having a healthy biological child. How do we define “disease”, though, and when does something go from being a disease to just an undesirable trait? Where do we draw the line, and who draws that line? Does a government or regulatory body have the right to decide for everyone? I don’t know if anyone has the right answers to these questions or any others that will come up as this technology further improves. However, as with all other major advances in science, we must expect and trust scientists to thoughtfully weigh the ethical questions behind their work, and to act in the best interest of humanity.

Big advances in science are always exciting, and from all indications the CRISPR/ Cas9 technology still has numerous uses which we haven’t even begun to study. Thus, until the next big discovery rolls along and takes the world by storm, everything’s getting a little CRISPR.