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Simulation Of Drosophila Circadian Oscillations, Mutations, And Light Responses By A Model With Vri, Pdp-1, And Clk, Paul Smolen, Paul E. Hardin, Brian S. Lo, Douglas A. Baxter, John H. Byrne

Journal Articles

A model of Drosophila circadian rhythm generation was developed to represent feedback loops based on transcriptional regulation of per, Clk (dclock), Pdp-1, and vri (vrille). The model postulates that histone acetylation kinetics make transcriptional activation a nonlinear function of [CLK]. Such a nonlinearity is essential to simulate robust circadian oscillations of transcription in our model and in previous models. Simulations suggest that two positive feedback loops involving Clk are not essential for oscillations, because oscillations of [PER] were preserved when Clk, vri, or Pdp-1 expression was fixed. However, eliminating positive feedback by fixing vri expression altered the oscillation period. Eliminating …