Why Make Memories?

cellular data recorders offer the capacity to measure biologically relevant signals15,16,17,18,19 in places that are otherwise difficult to access, such as inside the body20,21, and over time22

It is challenging to study how pneumococci control virulence factor expression, because cues of natural environments and the presence of an immune system are difficult to simulate in vitro

With this approach, neurons that show E-SARE–driven expression in response to stimuli are permanently labeled by the fluorescent protein during the time window specified by the drug

Expression of a drug-inducible Cre recombinase downstream of E-SARE enabled imaging of neuronal populations that respond to monocular visual stimulation and tracking of their long-distance thalamocortical projections in living mice

The feedback loop permits sustained induction of recombinant proteins without massive quantities of inducer.

recording past events, to study localization of single-cell transcriptional events within the gut

a high-fidelity memory device might allow researchers to identify cell populations responsive to specific events and track their progression through the cellular response