Spatiotemporal control of gene expression with pulse-generating networks

Area of Science:

• Synthetic biology
• Bacterial communication
• Genetic circuit engineering

Background:

• Coordinated behavior in cell communities is a key challenge in synthetic biology.
• Artificial networks are needed to achieve multicellular coordination.
• Understanding natural regulatory motifs can inform synthetic system design.

Purpose of the Study:

• To design a synthetic multicellular bacterial system for coordinated behavior.
• To engineer receiver cells exhibiting transient gene expression in response to signals.
• To investigate the role of regulatory motifs in synthetic gene circuits.

Main Methods:

• Engineered sender cells to synthesize acyl-homoserine lactone (AHL) inducer.
• Developed a pulse-generator circuit in receiver cells with a feed-forward motif.
• Utilized simulation models to engineer circuit variants and predict responses.
• Experimentally validated circuit behavior and quantitative responses.

Main Results:

• Receiver cells exhibited transient GFP expression in response to sustained AHL.
• Engineered pulse-generator variants showed varied pulse duration and intensity.
• Pulse amplitude and timing depended on both inducer concentration and its rate of increase.
• The system demonstrated spatiotemporal behavior, distinguishing between nearby and distant sender cells.

Conclusions:

• The synthetic multicellular system effectively achieves coordinated transient gene expression.
• Feed-forward motifs are crucial for precise temporal control in synthetic circuits.
• The pulse generator serves as a model for understanding natural regulatory systems.
• This system offers a novel approach for spatiotemporal control in bacterial communities.