Using CRISPRi-Based Feedback Loops to Reduce Resource Competition in Multimodule Systems

The Negatively Competitive Regulatory (NCR) controller significantly increased module coactivation in synthetic gene circuits.

• Cellular resource limitations can cause unintended interactions among gene circuit modules.
• Positive feedback in circuits may lead to Winner-Takes-All (WTA) behavior, where one module dominates at the expense of others.
• The NCR controller was implemented using CRISPR interference to mitigate WTA behavior in two gene circuits.
• By introducing negative feedback, the NCR controller reallocates resources from more active modules to less active ones.
• Experimental results show that the NCR controller effectively regulates resource competition and enhances the modularity of gene circuits.

Simplified