Project

The design for the cell 1: The genetic circuit can be divided into three different functional sections.
The first one in the graph is the detecting Section. By using this section you can detect the cell density according to the intensity of the red fluorescence. The detecting section is especially useful when you incubate two different kinds of E.coli in a coculture.

The second one is the Helper section. We call it helper section because the LuxR protein is the prerequisite for the activation of PLux. Here we used a constitutive promoter to regulate the expression of the LuxR protein.

The core section is the convertible switch. Convertible switch is a genetic device that can switch between two convertible states, which, here, represents a different survival strategy for the cells each.

When adding Arabinose/AHL different genes will get expressed behind the two mutually-repressive promoters. That means when added into the culture, AHL will diffuse into the cell bind the LuxR protein and form a complex which can activate the LuxPr promoter and then the genes of rhII capR and araC will express. Then the AraC protein will bind to the PBad/araC promoter and repress the expression of the aiiA and another capR gene. However, you can turn the switch to the other side by adding Arobinose. When adding Arobinose into the culture, the repression functional molecular AraC protein will get released from the PBad/AraC promoter. With the expression of the aiiA gene the signal molecular will get digested and therefore decrease to a proper level which is not high enough to activate the LuxPr promoter.
The most important thing in this section is the capacity of the two different promoters luxPr and PBad/araC are quite different. When the luxRr promoter is activated, its higher capacity will express more chloromycetin resistant protein and another important thing is by sensing the AHL which is sent out by cell 2 it can produce another kind of signal molecular BHL.
Cell 2 is similarly designed as Cell 1