分支链路对基因调控网络路径稳定性的影响分析

Analysis of the Effect of Branch Position on the Trajectory Stability of Gene Regulatory Networks

摘要: 揭示基因调控网络的动力学特征与网络结构的关系是系统生物学的研究热点，本文针对典型的动力学特征——路径稳定性，以调控网络的主干结构ITC模型为基础，分析了在ITC模型的不同位置接入分支链路后，网络路径稳定性的变化情况。从理论上证明了在ITC模型的不同位置接入分支链路对路径稳定性具有不同的影响。一方面，在ITC模型的起点中加入分支链路或者在ITC模型之外加入独立分支链路，路径稳定性降低；另一方面，在ITC模型的末端加入分支链路会提高路径稳定性。此外，实验模拟的结果表明，在ITC模型的中间节点加入分支链路，网络的路径稳定性会受到上述两种作用的综合影响。本研究结果不仅能够帮助揭示调控网络中路径稳定性的形成机制，也能够在合成生物学中指导设计稳定的人工生物网络，具有理论和实践两方面的意义。

Abstract: Revealing the relationship between the dynamics and structure of gene regulatory networks is a challenging issue in system biology. This study focuses on the trajectory stability which is a typical dynamic characteristic of regulatory networks. Based on the ITC network model which forms the main structure in a regulatory network, we analyzed how the positions of branches affect the tra-jectory stability of the network. In theoretical analysis, it has been proven that the branch’s position will affect the trajectory stability in two ways. On one side, if inserting an independent branch or a branch at the first node of the ITC model, the trajectory stability of the network will decrease slightly; on the other side, if inserting a branch at the end node of the ITC model, the trajectory stability will considerably increase. In simulation, it has also been shown that if inserting a branch at middle position, the trajectory stability will be affected by a combination of these two effects. These findings can not only help to reveal the topological origin of trajectory stability in regulatory networks, but to provide guidance in designing robust artificial network in synthetic biology.