细胞信号网络功能鲁棒的简并性拓扑特征

细胞信号网络对于外界环境的干扰表现出优良的鲁棒性,但是其维持功能鲁棒的内在机制尚未明确,本文研究了细胞信号网络功能鲁棒性的拓扑特征。选择布尔网络模型模拟细胞网络的动态行为,利用网络节点状态的扰动模拟外界环境干扰。基于演化策略探寻不同网络拓扑的功能并分析其在干扰环境下的鲁棒性,采用埃德尔曼提出的基于信息论的计算方法评估网络拓扑的简并度、冗余度和复杂度等拓扑属性,对比分析它们与功能鲁棒度的相关性及作用机理。结果显示,在网络模型的演化过程中,其拓扑简并度与功能鲁棒度显著正相关,相关性水平高于拓扑冗余度与鲁棒度的相关性。并且,随着鲁棒度的提升,网络的节点数和复杂度也随之升高,同样简并度与网络的节点数和复杂度的相关性高于拓扑冗余度与网络的节点数和复杂度的相关性。这说明增加的网络节点以简并的方式同时提高了网络拓扑的鲁棒度和复杂度。因此,细胞网络功能鲁棒性的拓扑特征是简并而不是冗余,简并为解决生物系统的复杂问题提供了有效手段,为人工系统的可靠性设计提供有益的借鉴。

Degenerate topology analysis of robustness in cellular signaling network

Cellular signaling network shows good robustness during interference, but the intrinsic mechanism about it is still not clear. This study aims to analyze the topological structure properties of the cellular signaling network. Boolean network was used to simulate the dynamic cellular signaling network, and the disturbance of network nodes was used to simulate the interference of external environment. The function of different topological networks was explored by using evolutionary strategy to analyze their robustness under various interference environments. By adopting the quantitative definitions proposed by Edelman et al, we measured the topological characteristics of degeneracy, redundancy and complexity in the evolved Boolean networks, and compared their mechanism and contributions to the robustness. As is shown in the results, in the progress of evolution of the network, the degeneracy is positivly correlatlive with the robustness significantly, and the correlation coefficient between the degeneracy and the robustness is better than that between the redundancy and the robustness. And network nodes and complexity increase with the robustness. They also have a better correlation with degeneracy than that with redundancy,which demonstrates that the increased nodes improve the robustness and complexity in a degenerate way. Therefore, the topology characteristic of cellular signaling network is the degeneracy rather than the redundancy. The degeneracy provides an efficient method for solving the complex problems of biology system and offers references for the reliability design of manual system.