| Gene regulation participates in most life activities,affecting cell growth,mutation and apoptosis,and has dominated research in the field of life science.Previous investigations have demonstrated that gene regulation process has stochastic nature and time delay.Impacts of Gaussian white noise and time delay in gene transcription regulation process have been investigated.As the actual noises are Gaussian noise and non-Gaussian noise,the thesis theoretically interprets impacts of nonGaussian noise,Gaussian colored noise and time delay in gene regulation mechanism by the model of TF-A and the model of Myc/E2F/Mi R-17-92 network for gene transcription regulation.The primary contents and originalities in this thesis can be epitomize as follows:First,time delay and Gaussian noise are coupled to the model of transcription factors resulting in gene regulation.And the corresponding FPK equation is obtained by small time delay approximation method.Stationary probability distribution and mean first passage time are calculated.It is found that time delay can be considered as a control parameter of gene switch,and not only weaken the stability of the ”off” state,but also enhance the stability of the ”off” state.Second,stationary probability distribution and mean first passage time of the Myc/E2F/Mi R-17-92 model with non-Gaussian noise and Gaussian colored noise are highlighted.It is clarified that the role of noise parameters in the stationary probability distribution and mean first passage time.Research results illustrate that: 1.These parameters can not only affect the efficiency of gene transcription,but also control gene switch.2.Appropriate noise parameters can enhance the stability of ”on” state.At last,the conclusions of the two models are analysed in this thesis.It is found that multiplicative noise,whether non-Gaussian noise or Gaussian color noise,has the same effects on gene switch mechanism.Diverse additive noises have different effects on the gene switch mechanism. |
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