Bacteria Can Distinguish Harmful vs. Helpful Viruses

When they are not busy attacking us, germs go after each other. But when viruses invade bacteria, it doesn’t always spell disaster for the infected microbes: Sometimes viruses actually carry helpful genes that a bacterium can harness to, say, expand its diet or better attack its own hosts.

Scientists have assumed the bacterial version of an immune system would robotically destroy anything it recognized as invading viral genes. However, new experiments at Rockefeller Univ. have now revealed that one variety of the bacterial immune system, known as the CRISPR-Cas system, can distinguish viral foe from friend. And, the researchers report in a paper published this week in Nature, it does so by watching for one particular cue.

Fonte: Laboratory Equipment