Population-level amplification of gene regulation by programmable gene transfer.

Engineering cells to sense and respond to environmental cues often focuses on maximizing gene regulation at the single-cell level. Inspired by population-level control mechanisms like the immune response, we demonstrate dynamic control and amplification of gene regulation in bacterial populations using programmable plasmid-mediated gene transfer. By regulating plasmid loss rate, transfer rate and fitness effects via Cas9 endonuclease, F conjugation machinery and antibiotic selection, we modulate the fraction of plasmid-carrying cells, serving as an amplification factor for single-cell-level regulation. This approach expands the dynamic range of gene expression and allows orthogonal control across populations. Our platform offers a versatile strategy for dynamically regulating gene expression in engineered microbial communities.