Software Tutorial: Ensuring a mathematically controlled simulation for comparing simple regulation to negative autoregulation

Note: We are currently in the process of updating this tutorial to the latest version of MCell, CellBlender, and Blender. This tutorial works with MCell3, CellBlender 3.5.1, and Blender 2.79. Please see a previous tutorial for a link to download these versions.

In this tutorial, we will use CellBlender to adapt our simulation from the tutorial on negative autoregulation into a mathematically controlled simulation.

First, open the file NAR_comparison.blend from the negative autoregulation tutorial and save a copy of the file as NAR_comparison_equal.blend. You may also download the completed tutorial files here.

Now go to CellBlender > Reactions to scale up the simple regulation reaction in the negative autoregulation simulation as follows: for the reaction X2’ -> X2’ + Y2’, change the forward rate from 4e2 to 4e3.

Next go to CellBlender > Run Simulation and ensure that the following options are selected:

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  1. Set the number of iterations to 20000.
  2. Ensure the time step is set as 1e-6.
  3. Click Export & Run.

Click CellBlender > Reload Visualization Data. You have the option of watching the animation within the Blender window by clicking the play button at the bottom of the screen.

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Now go back to CellBlender > Plot Output Settings and scroll to the bottom to click Plot; this should produce a plot. How does your plot

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Save your file before returning to the main text, where we will interpret the plot produced to see if we were able to obtain a mathematically controlled simulation and then interpret the result of this simulation from an evolutionary perspective.

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