By feeding strings of human-written data into colonies of bacteria, scientists have discovered a way to turn tiny cells into living, squirming hard drives.
A team of Harvard scientists led by geneticists Seth Shipman and Jeff Nivala has just developed a fascinating way to write chunks information into the genetic code of living, growing bacterial cells. It could be the code for a computer program or the lines of a poem.
Ref: Molecular recordings by directed CRISPR spacer acquisition. Science (9 June 2016) | DOI: 10.1126/science.aaf1175
The 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-Cas system of E. 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 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.