Team:ETH Zurich/Experiments 6
From 2013.igem.org
The game with the GFP receiver construct
The receiver and sender colonies were plated in the honeycomb hexagonal pattern on LB-Agar for a timelapse experiment to follow the OHHL diffusion from sender cells to receiver cells.
The mine cells/sender cells are represented by green circles, the numbers indicate how many mines surround the non mine colonies . The grey-scale makes it easy to identify 1,2 or 3 surrounding mines. As predicted in our model a gradient is visible in the colony. This gives the player information about the location of the mine. Based on this information , the player can decide about the next move, as in to which colony the substrate needs to be added in order to move past the mines without detonating them , or to flag them.
The game with the hydrolases receiver construct
1. Receiver cells signal no mines in their vicinity. If there is no mine adjacent to a non-mine colony, no OHHL is reached to the receiver cell and so no OOHL is processed. In this case, a constitutive hydrolase is expressed which on addition of the multi-substrate will give a yellow color. This indicates that there are no mines adjacent to this colony.
2.Receiver cells respond to low OHHL levels: If one mine cell is close to a non-mine colony and by OHHL diffusion takes place to reach the non-mine colony. Due to a bandpass filter using the LuxR system in the non-mine colony,low concentrations of OHHL is detected which activates a reporter. Addition of the multi-substrate to this colony produces a salmon color and this indicates one mine is adjacent to the colony just played.
3.Receiver cells respond to high OHHL levels: If there are two or more mine colonies adjacent to a non-mine colony, a higher concentration of diffused OHHL will be processed by the receiver colony. The LuxR system works as a bandpass filter again and induces the expression of another reporter to show that 2 or more mines surround the selected colony. Addition of the multi-substrate to this colony produces a magenta color that indicates more than two mines adjacent to this colony.