Shipman, SethNivala, JeffreyMacklis, JeffreyChurch, George2017-09-132016Shipman, S. L., J. Nivala, J. D. Macklis, and G. M. Church. 2016. “Molecular Recordings by Directed CRISPR Spacer Acquisition.” Science 353 (6298) (June 9): aaf1175–aaf1175. doi:10.1126/science.aaf1175.0036-8075http://nrs.harvard.edu/urn-3:HUL.InstRepos:33894957The ability to write a stable record of identified molecular events into a specific genomic locus would enable the examination of long cellular histories and have many applications, ranging from developmental biology to synthetic devices. We show that the type I-E CRISPR (clustered regularly interspaced short palindromic repeats)-Cas system of Escherichia coli can mediate acquisition of defined pieces of synthetic DNA. We harnessed this feature to generate records of specific DNA sequences into a population of bacterial genomes. We then applied directed evolution so as to alter the recognition of a protospacer adjacent motif by the Cas1-Cas2 complex, which enabled recording in two modes simultaneously. We used this system to reveal aspects of spacer acquisition, fundamental to the CRISPR-Cas adaptation process. These results lay the foundations of a multimodal intracellular recording device.en-USJournal Article2017-06-2920162017-09-1310.1126/science.aaf1175