Selfish genes fight each other with DNA-destroying CRISPR systems

An illustration of plasmids, small circles of bacterial DNA NANOCLUSTERING/SCIENCE PHOTO LIBRARY
Bacteria host bits of DNA that can replicate spread to other bacteria. Now, researchers have discovered that these “selfish genes” wage war on their rivals using DNA-destroying CRISPR systems.
CRISPR has become famous as a way of editing genes, but in bacteria, CRISPR systems often act as an immune system, targeting dismantling the DNA of invading viruses.
Rafael Pinilla-Redondo at the University of Copenhagen in Denmark his colleagues have shown that some of the self-replicating bits of DNA …