WIKIMEDIA, MATTOSAURUSUtilizing the bacterial CRISPR/Cas adaptive immune system, researchers at Harvard have developed a method for permanently recording molecular events in living cells, according to a report published in Science today (June 9). The system integrates specific synthetic DNA elements into the bacterial genomes in temporally-ordered arrays, which, once sequenced, can provide a readout of the bacteria’s timeline of DNA events.
“The importance of the work is in providing a proof of principle: that a fascinating bacterial immune system may be utilized as a tool harboring an impressive recording capacity,” said microbiologist Udi Qimron of Tel Aviv University who was not involved in the work.
The CRISPR/Cas system works by snipping short DNA elements from the genomes of infecting viruses, integrating those elements into the bacterium’s genome (at the CRISPR locus), and using the RNAs produced from the integrated elements to direct destruction of the corresponding virus. In essence, the bacterium keeps a DNA account of its viral foes, and uses it against them.
Integration of these viral DNA elements—or oligomers—into the CRISPR locus is nonrandom: the most recent viral elements are consistently integrated ahead of ...
