振荡周期不受温度影响的生物调控网络的数值研究

Numerical Analysis of Oscillatory Regulatory Networks with Temperature-Independent Oscillation Period

生物学中普遍存在的生物钟的基本特性之一是其振荡周期不随环境温度变化而变化,即具有温度补偿特性,其机制是近年来研究的热点.本文对具有振荡周期不随温度变化的基因调控网络做了数值分析.温度补偿振荡是一种系统水平的性质,跟网络的拓扑结构具有密切联系.对多节点的仅有抑制性调控关系的随机网络的计算表明,温度补偿的振荡行为可以仅仅通过采用适当的拓扑结构实现,而不需要细调的动力学参数.对所有3个节点网络的穷举发现,温度补偿振荡网络结构上是两种性质互补的振荡网络模体的组合,即延迟的负反馈网络)、抑制子振子和激活抑制振子、底物耗尽振子的组合.对网络振荡周期随参数的敏感性分析表明,温度补偿振荡可以通过熔断机制来实现,振荡周期仅敏感依赖于极少数的反应速率常数,而这些常数的活化能很小因为阻断了温度对振荡周期的影响.

Oscillatory gene interaction networks whose oscillation period is independent of temperature weretheoretically investigated with multiple-node-networks having up to twenty nodes and with few-node-networkswith only three nodes. Analyses revealed that the temperature independent oscillation period can be achievedthrough proper re-linkages between the nodes. W th only inhibitory interactions in the networks , and withoutfine-tuning parameter values , most of multiple-node networks can evolve into proper topologies and oscillate witha period not affected by temperature fluctuations. The analysis revealed that temperature-compensatedoscillations occur at the system levd and depend strongly on the topological structure of the networks.