Study On Gene Switch And Stochastic Resonance In The Gene Transcriptional Regulatory System

The effects of bounded noise and time delay on both gene transcription regulation systems and their stochastic resonance phenomena are studied in this thesis.Firstly,the background and significance of the research on gene transcription regulation model and the research status are introduced.Secondly,the nature of the gene transcription control system under bounded noise and time delay is studied in depth,and a series of research results are obtained.Switch process induced by the sine-Wiener noises in the gene transcriptional reg-ulatory system were investigated by numerical simulations.Results show that(i)Only multiplicative noise(B)which is the fluctuation of degradation reaction rate can induce a switch process(on?off)as the intensity of multiplicative noise increases for the case of uncorrelated noises;(ii)For the case of correlated noises,the switch process can be in-duced not only by intensity of multiplicative noise but also by intensity of additive noise(A)which is the fluctuation of synthesis reaction rate and the cross-correlation intensi-ty between the multiplicative and the additive noise can also induce the switch process;(iii)A successive switch process(on?off?on)occurs accompanied by a noise intensity increase when the correlation intensity takes larger value;(iv)When the value of time delay(?)increases,the switch process(on?off)occurs and in the synergistic effect of the correlation intensity and the linear term time delay,there is a sensitive region which is a fast switching process region.These results suggest that external perturbations and delays can add or inhibit gene transcription processes and provide a theoretical possibility for regulation of gene transcription processesWithin a reasonable range of noise intensities,the presence of an appropriate period-ic signal can excite the occurrence of stochastic resonance phenomena.Results show that(i)The resonance intensity is more sensitive to multiplicative noise than additive noise;(ii)The resonance intensity is positively correlated with the correlation strength(?)and the impact is global;(iii)The time delay has no effect on the resonance intensity;(iv)The resonance intensity and the periodic signal intensity(C)are negatively correlated and the strong influence is global.