MIT biological engineers have devised a way to record complex histories in the DNA of human cells, allowing them to retrieve “memories” of past events, such as inflammation, by sequencing the DNA. This analog memory storage system — the first that can record the duration and/or intensity of events in human cells — could also help scientists study how cells differentiate into various tissues during embryonic development, how cells experience environmental conditions, and how they undergo genetic changes that lead to disease. The new MIT approach is based on the genome-editing system known as CRISPR, which consists of a DNA-cutting enzyme called Cas9 and a short RNA strand that guides the enzyme to a specific area of the genome, directing Cas9 where to make its cut. CRISPR is widely used for gene editing, but the MIT team decided to adapt it for memory storage. In bacteria, where CRISPR originally evolved, the system records past viral infections so that cells can recognize and fight off invading viruses. http://healthsciencemag.org/2016/08/18/recording-analog-memories-in-human-cells/
