Since they were first discovered in the 1980s, retrons have puzzled researchers who simply wanted to know what these bacterial DNA sequences actually did. Now, EMBL scientists have identified that some retrons encode toxin proteins, which they keep inactive with the help of a small DNA fragment. When a bacterial virus (phage) attacks bacteria, the small DNA can sense the attack and unleash the toxin.
Click here for original story, Researchers identify what flips the switch to activate a retron’s toxins to prevent a viral spread
Source: Phys.org