Dynamics of dual feedback Goodwin-Griffith oscillators coupled through OR gate.

<p><b>A1-2</b>. Trajectories of protein-products of TF genes A and B which are two independent GG oscillators coupled through A-OR-B type logic as given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0104328#pone-0104328-g002" target="_blank"><b>Figure 2B</b></a><b>2</b>. Simulation settings are , , and which required a critical Hill coefficient of <i>_Cn_a</i> = 8. Total simulation time is 200 (number of lifetimes of the protein product of TF gene A) and integration step is . For each promoter A/B the parameter will be split into where corresponds to self-regulation and corresponds to cross regulation. Under identical values of all the parameters the system generates synchronized oscillations with a period of . Upon introduction of perturbation in from scaled time 0 to 100 (where ), the amplitude of TF gene A is reduced with a phase shift and the period of entire system that includes both TF genes A and B remains the same. A2 is a magnification of certain range of A1. <b>A3-4</b>. Effect of perturbation in only one of the split parameters associated with TF gens A/B. Here is perturbed to . The system seems to be unstable and generates beats. A4 is a magnification of certain range of A3. <b>A5-6</b>. Here is perturbed to . Period of beats seems to increase as the disproportion among the split parameters increases. A6 is a magnification of certain range of A5. <b>B1-2</b>. Effect of perturbation in the parameter which is raised to from the default value in the interval from 0 to 100. Increase in reduces the amplitude of both the TF genes A and B with a phase shift and the period of oscillations of the entire system remains the same as in A1-2. B2 is a magnification of certain range of B1. <b>C1-2</b>. Effect of perturbations in the parameter which is raised to from the default value in the time interval from 0 to 100. Increase in reduces the amplitude of both the TF genes A and B without a phase shift and the period of oscillations of the entire system remains the same as in A1-2. C2 is a magnification of certain range of C1.