Team:EPF-Lausanne/Modeling

From 2008.igem.org

Revision as of 17:07, 29 October 2008 by Ndenerva (Talk | contribs)

Contents

Double input model

Here we describe a semi-quantitative model of the Lux band-pass detector and the Rhl high-pass detector. The model describes each proteins and sending molecules involved in the system. At this stage, we test the ability of the system to process a constant input of green or red (ALux or ARhl) and choose an output state, either red or green.

Genscheme.jpg

States

Processor states.jpg

ODEs

Processor model.jpg

Parameters

Processor param.jpg

Simulation

The model nicely shows that for a certain range of AHL concentrations, the system can turn into either green or red. the following figure shows that we can achieve the band-pass filter on the red input and a high pass on the green input. Therefore, we can generate the choosen rule set where only medium level of red (AHL Lux) and low to medium level of green (AHL Rhl) can turn the system into the green state. Processor sim.jpg

Bistable switch model

XCl2.JPG

States

Bistable states.jpg

ODEs

Bistable model.jpg

Parameters

Bistabl param.jpg

Simulation

GFP (left) and RFP (middle) expression for concentration of AHL (Lux or Rhl) pulses. On the right, figure shows the ratio of GFP/RFP. This results shows that a given range of AHL can produce the green state. This is in good agreement with the rule set that we propose, where only medium level of red input (AHL Lux) and low to medium level of green input (AHL Rhl) can generate green.

Bistabl sim.jpg

The following figures show the dynamics of the different states involved in the system for different AHL pulses. On the left, the system is locked into the green state after a pulse of 1.6 uM of Lux AHL and 3 uM of Rhl AHL. On the right, the system is locked into the red state after a pulse of 4 uM of Lux AHL and 4 uM of Rhl AHL. The model nicely shows the dominance of either TetR (purple line) or LacI (light blue line) for the green, respectively red state. It also shows the importance of the twos negative feedback made by the M represssor (dashed line) and CI (black line) to maintain the system in the green state.


Green state 1-6 3.jpg Red state 4 4.jpg