You may have recently seen the word “embryo” in the news more often than usual. Headlines such as “Scientist makes case to edit embryos” and “British Scientists Want Permission to Genetically Edit Viable Human Embryos” are increasingly common. And if you’ve been following the latest stories about CRISPR, a promising and (relatively) new genetic engineering tool, you likely knew something like this was coming. If not, you may be wondering what on earth is going on and whether or not you’ve stepped into the real-life version of a sci-fi movie (Gattaca, I’m looking at you).
CRISPR (also known as CRISPR-Cas9) is a naturally-occurring bacterial immune system that can precisely and effectively remove pieces of DNA. It evolved to help bacteria fight off viral infections, but in 2012 it was also used to effectively edit the DNA of human cells for the first time. You can think of CRISPR as a genetic cut-and-paste tool that can replace unwanted pieces of DNA with whatever pieces you want to insert.
So why do scientists want to use it on embryos? Well, CRISPR is easier to use and more effective than traditional genetic engineering tools. It can help us learn a lot about the roles of certain genes and how they affect our development. After all, though we know that humans have approximately 21,000 genes, the function of many of those genes remains unknown. Imagine if we could easily inactivate a particular gene and study the effects of its absence to learn more about its function. That’s exactly what Dr. Kathy Niakan, the British scientist mentioned in the above articles, wants to do. She wants to try removing certain genes in human embryos (which will not be implanted into any womb) to find out what their role is in human development.
While the power of CRISPR is well-known and praised within the science community, some fear that its power could be used unethically. The term “designer babies” may spring to mind. After Chinese scientists published research on the use of CRISPR in human embryos in April 2015, the use of CRISPR in this type of cell was briefly halted until, legal, science, and ethics experts convened in Washington DC later in the year to discuss its ethical implications. The consensus? Let’s plan to use it clinically, but let’s do it slowly and responsibly. While we are far off from CRISPR being used to cure genetic diseases such as cystic fibrosis, such a reality is closer now than it ever has been. While this is incredibly exciting, it also forces us to seriously contemplate the regulation of CRISPR in humans.
Overall, the headlines point to something that is likely inevitable but (in my opinion) okay. The knowledge we will gain from CRISPR experiments will help us to learn more about ourselves as a species and more about the relatively mysterious process of our development. If you want to learn more about CRISPR, Jennifer Doudna, one of the scientists that led to its discovery, gives a simple, concise overview of the technology and its ethical issues in this 2015 TED Talk.