关键词: 合成生物学, 基因元件, 资源竞争, 模块化, 设计策略

Abstract:

In synthetic biology, gene modules are fundamental components that facilitate the execution of various biological functions. “Modularity” refers to the property where known genetic elements maintain their relatively independent functions after being assembled into specific gene circuits. Unlike traditional engineering systems, which often possess independent and stable characteristics, gene circuits must navigate the complexities of dynamically fluctuating cellular environments. This inherent variability means that the effectiveness of gene circuits in producing functional proteins is highly contingent upon the availability of intracellular resources. When these resources are scarce, it can create significant bottlenecks that impede the overall functionality of the gene circuits. Moreover, gene modules do not typically operate in isolation; rather, they are integrated into complicated network systems that interact with other modules to achieve multifaceted regulatory objectives. This interconnectedness leads to competition among various modules for limited intracellular resources, which disrupts the basic principle of modular design. Restoring the modularity of gene circuits is crucial for constructing universal models of life systems, which can further promote the intelligent development of artificial life systems. Recently, increasing studies have focused on how this resource competition impacts the performance of gene circuits, which have deepened our understanding of the underlying mechanisms and have paved the way for optimizing gene circuit designs to enhance their modularity and functionality. This review aims to comment on the influences of cellular resource competition on gene circuit functions, through exploring various aspects, including the fluctuations in noise levels within gene circuits, the coupling relationships among different gene modules, and the emergent “winner-takes-all” phenomenon. Additionally, we summarize existing strategies for controlling these challenges, such as the orthogonal design of cellular resources, the regulation of single gene modules, and the coordinated control of multiple gene modules. With the rapid development of synthetic biology, artificially designed gene circuits are becoming increasingly complicated in both structures and functions. This trend suggests that future research will no longer be limited to simple resource competition control systems, but instead will need to expand to larger-scale research areas. At the same time, research directions should extend from basic research to practical applications, ultimately aiming to construct precisely controllable artificial life systems.

Key words: synthetic biology, genetic parts, resource competition, modularity, design strategies