Research On The Dynamics Of Rb-E2F-miR And P53-Mdm2-Wip1 Gene Regulatory Networks Influenced By Time Delay And Noise

Studies have shown that P53 and E2 F undergo significant changes in a large number of cancer cells,affecting the fate of cells.P53 and E2 F cooperate to regulate the expression of target genes and thus control cell process.Due to the existence of time delay in various systems,we study the performance of the system by analyzing the influence of time delay.In addition,due to the low copy number of molecules and the fluctuation of the environment,we also consider the effect of noise on the system.Therefore,this paper focuses on the dynamics of Rb-E2F-mi R and P53-Mdm2-Wip1 gene regulatory networks under the influence of time delay and noise.First of all,in the first chapter,the prerequisite knowledge,the regulation mechanism of transcription factors E2 F and P53,the research status and the main work are introduced in this paper.Second,the bifurcation analysis of the three regulatory pathways mediated by mi R-17-92 was conducted in the second chapter,and the results show that there is no significant difference in the regulation of E2 F between the three pathways regulated by mi R-17-92.Then,by using the Hopf bifurcation theory and numerical simulation,the dynamic characteristics of delay differential equations are studied.It is found that time delay is not only an important condition for the generation of Hopf bifurcation,but also affects the period and amplitude of the Hopf bifurcation.In addition,the effects of time delay and important parameter combinations on the stability of the system are also studied,and we found that changing the parameter values appropriately can not only cause the system to oscillate but also change the state of the system.Finally,the dynamic behavior of the E2 F system under the influence of time delay and noise is studied.It is found that the noise can also cause the oscillation of the system without time delay,while the noise can also promote the oscillation with time delay.In addition,the dynamic characteristics of the P53 gene regulation model under the influence of time delay and noise are studied in chapter three.The existence and properties of the Hopf bifurcation of the P53 model at the equilibrium point are studied by using a method similar to that in the second chapter.Some important parameters are analyzed by bifurcation and the effects of time delay and parameters and the combination of time delay and noise on the system are studied through numerical simulation.The results show that changing the parameter values appropriately can not only cause system oscillation but also change the state of the system.The noise can cause system oscillation without time delay.However,the noise can not only promote the oscillation but also attenuate the oscillation under the action of time delay,and it is also found that the system has good robustness under the action of time delay.The above studies contribute to our further understanding of the regulatory mechanisms of E2 F and P53 in the cell cycle.Finally,the fourth chapter summarizes the research work,innovation points and future research prospects of this article.