Every winter, we take precautionary measures to fight the flu by getting inoculated with just enough of the virus so our bodies can learn how to build immunity. As it turns out, bacteria inside us have developed a tool to do the same thing when they are under attack by viruses (phages). Now, scientists around the world are using this microscopic immunity mechanism to make incredible breakthroughs in genetic research.
Sylvain Moineau, a researcher at Université Laval, has played a leading role in an international collaboration that has identified the adaptive immunity system known as CRISPR-Cas (Clustered, Regularly Interspaced, Short Palindromic Repeats), found in about half of all bacteria. Moineau’s group demonstrated how bacteria use CRISPR-Cas to defend against incoming phage DNA by creating a precise double-strand break. Here’s how it works: when a phage attacks, a bacteria takes a small portion of the phage’s DNA, recording a memory and developing immunity. The next time the phage attacks, the bacteria has all the information it needs to ward off infection.
Moineau’s groundbreaking studies paved the way for others to develop technologies utilising CRISPR-Cas, which has been called “the holy grail of genome engineering” and has since been adopted by thousands of laboratories around the world. The discoveries made by Moineau and his team are helping scientists tinker with the smallest building blocks of life to find new solutions to some of the world’s most pressing problems. CRISPR-Cas has been used to genetically modify crops to resist droughts and produce higher yields. It has also been used to screen human cells and locate genes underlying biological processes—a crucial step in identifying triggers for larger problems such as cancer and infectious diseases.