A phage that resists all forms of the antiviral defense known as CRISPR has an unusual means of survival.

Joseph Bondy-Denomy knew he could find viruses that would be hard to kill. But he wasn’t expecting to discover one that was quite so invincible.

The viruses that Bondy-Denomy studies at the University of California at San Francisco don’t bother humans. Known as phages, they infect and kill bacteria instead. Bacteria can defend themselves against these assaults. They can recognize the genes of the phages that threaten them, and deploy scissorlike enzymes to slice up those genes and disable the viruses. This defense system is known as CRISPR. Billions of years before humans discovered it and used it as a tool for editing DNA, bacteria were using CRISPR to fight off phages.


Adenosine [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], from Wikimedia Commons

Read more…