Tuesday, September 13, 2011

SBML and Antimony as modules

The modular framework in TinkerCell is designed to support practically any format that can be loaded into TinkerCell. As a consequence, Antimony and SBML files can be used as modules. In the schreenshot below, a TinkerCell oscillator module is modeled using an Antimony script. The modular framework maps variables in the Antimony script to variables in the conceptual model.

Friday, September 2, 2011

Same network, different behaviors

Since TinkerCell decouples the notion of a "biological network", or system, from the actual mathematical model, it is possible to generate multiple models of the same system. The screenshot below is of an enzyme with two states, enz1 and enz2. Both states are auto-catalytic. Because of this dual positive feedback, one would guess that the system would become bistable. However, this system is bistable only for certain model implementations. If steady state assumptions are used in the model, then the system is bistable. If mass-action kinetics is used, we see that the intermediate states of the enzyme catalysis process are not really in steady state, and in such models, the bistability also disappears. 

New video of ring oscillator model

Coupled oscillator modules

TinkerCell's modular framework allows users to perform experiments such as the one shown below. Here, two oscillators are connected to each other. Each oscillator *can* take multiple models. This is the benefit of using modular design -- the internal details can be swapped without affecting the conceptual overall design, i.e. two coupled oscillators. One of the TinkerCell Python plugins allows users to test all possible oscillator combinations. Currently, only two oscillator designs are available (you can add more and submit to the repository if you want!). So, the total number of combinations are 4, which are the 4 graphs shown below. Notice that in one of the designs (top left), one oscillator somewhat controls the frequency of the other. By tuning parameters further, this design can actually be used to create an oscillator where the frequency is also oscillating.