Abstract

Natural oscillators exhibit remarkable precision in their period while being robust to environmental changes. While many synthetic gene circuits have already been engineered to achieve various functions, many exhibit unreliable and unpredicted behaviors. In this project, we aim to engineer precise genetic oscillators and to characterize the relationship between period and precision. Using mutagenesis, we have generated large libraries of different circuit variants with the key regulatory regions of the circuit mutated to observe a wide range of dynamics. We focus on two different circuit architectures, the repressilator and the dual feedback oscillator. Modelling of both circuits has shown that there are distinct trends in circuit parameters that are necessary to achieve the highest precision. In order to accurately characterize these circuit dynamics at the single-cell level, we employ a microfluidic device called the mother machine. We show these trade-offs are present in the circuit libraries, specifically between the period length and precision for both the repressilator and dual-feedback oscillator circuits. We also employ a mutagenesis method to generate novel oscillators with increased precision. By building such circuit libraries and characterizing the different dynamics we aim to gain a deeper understanding of the design principles of natural oscillators, while providing a tool with potential biotechnology applications.