基因转录调节系统中噪声和时间延迟诱导的相变行为研究

Noise and Delay Induced Phase Transition in the Gene Transcriptional Regulatory System

用定态概率分布来研究基因转录调节系统中噪声和时间延迟诱导的相变行为.结果表明,延迟时间、噪声间的关联强度、乘性噪声强度的增大均可引起系统发生相变,即系统由双稳态变成单稳态,系统中蛋白质浓度状态可由"开"到"关"或由"关"到"开"转换.但是,噪声间为正关联时,关联强度和延迟时间的增大对系统起相反作用,而噪声间为负关联时,关联强度和延迟时间的增大对系统起相同作用.此外,加性噪声强度的增大不会引起系统的相变行为,但可以改变系统状态的稳定性.

Transitions induced by noise and delay are studied with the stationary probability distribution function(SPDF) in a gene transcriptional regulatory system.The result indicates that the increase in the cross-correlation strength,time delay and the intensity of the multiplicative noise can induce a transition of the system,i.e.,the system becomes monostable from bistable and the protein concentration of the system can switches between 'on' and 'off' state.However,the cross-correlation strength and the delay time play an opposite role on the SPDF when the cross-correlation between noises is positive and the cross-correlation strength and the delay time play the same role on the SPDF in the case of the negative cross-correlation.The increase in the intensity of the additive noise dose not induce a transition,but can change the stability of the state of the system.