Intercellular CRISPRi for Distributed Genetic Circuits

Microbial communities and multicellular organisms employ diverse strategies for allocation of available resources, achieved through task distribution among specialized cells. Drawing inspiration from nature, several synthetic multicellular circuits have been recently constructed where a larger circuit is distributed into several cells in order to reduce the burden on individual cells. Here, we describe the implementation of multicellular logic-gate circuits in bacterial co-cultures that combine DNA messaging with CRISPRi regulation. Leveraging the easily programmable and information-dense DNA molecules, our system is composed of sender bacteria that transmit DNA messages encoding guide RNAs and receiver bacteria that receive them and express the guide RNAs to regulate transcription by CRISPR interference. We demonstrate several functional multicellular circuits representing digital logic gates that operate on timescales comparable to small molecule signaling: NOT, YES, AND, and AND-AND-NOT. The receiver cells process the inputs received to perform computations and generate a logical output.