CRISPR is so popular even viruses may use it

The celebrated gene-editing tool CRISPR started out as a bacterial defense against invading viruses. But it turns out the intended targets have stolen CRISPR for their own arsenals. A new study reveals that thousands of the bacteria-attacking viruses known as bacteriophages (phages, for short) contain the CRISPR system’s genetic sequences, suggesting they may deploy them against rival phages. The finding is a testament to the molecular weapon’s power—and may make CRISPR even more valuable as a laboratory gene editor. The discovery “opens doors for possible new applications of CRISPR systems,” says genomicist Mazhar Adli of Northwestern University’s Feinberg School of Medicine, who wasn't connected to the research. Like other viruses, phages cannot reproduce on their own. Instead, they hijack bacteria’s molecular machinery, often killing their hosts in the process. The CRISPR system enables bacteria to fight back. It includes repetitive stretches of DNA that match sequences of previously encountered phages. If these same phages attack a bacterium again, it uses this repetitive DNA to encode strands of RNA that can steer a partner enzyme, which acts like a pair of genetic scissors, to cut the phage’s genome at specific places. For about the past decade, scientists have been working to turn this immune defense into a gene-editing technique for myriad uses, including improving crop defenses, detecting pathogens, and fighting diseases such as cance...
Source: ScienceNOW - Category: Science Source Type: news