Team:UCSF/Project/Circuit/Design

Building upon our CRISPR conjugation project, we began to think about what types of alterations we could confer to cells using the CRISPRi system. One alteration we had in mind was a decision making ability that can be achieved with a circuit design. Many synthetic circuits have been created using multiple repressors as their switch. In our circuit design we plan utilize guideRNAs (gRNAs) in lieu of repressors which will allow for a highly scalable design.

Our synthetic circuit has been engineered to give cells a decision making ability between differential outputs and will utilize CRISPRi as a switching mechanism between these outputs. Depending on a high or low amount of chemical signal, our cells can produce either RFP or GFP. If there was a low amount of chemical signal, GFP and a gRNA to RFP will be produced. The gRNA will then combine with dCas9, which has been incorporated on a separate plasmid. The dCas9 will then repress the RFP. The inverse follows the same principle; if suddenly the chemical signal increases, RFP and gRNA to GFP will be produced. The gRNA will combine with dCas9 and repress GFP expression.