Team:DTU-Denmark

The aim of this project is to engineer a genetic bi-stable switch that produces two different, mutually exclusive outputs when given two different inputs. The switch is based on the repressor-anti-repressor system of the salmonella phages Gifsy1 and Gifsy2 and the λ-phage anti-termination system. The latest induced output will remain stable through generations, even once the input ceases, due to the phage regulatory systems.

We present the framework for this development and characterize the regulatory mechanisms by using fluorescent proteins as outputs. The dynamics of the system will be modeled and we will also attempt to characterize and submit the promoters, repressors and anti-repressors from the salmonella phages, as well as the two anti-terminator proteins from the lambda phage, as BioBricks.

There are multiple potential applications for biological "switches" such as this one in the world of biotechnology i.e. within the medical and environmental field.

Basic Concept

Figure 1: The basic concept of our project is illustrated:
Inducer 1 will activate Promoter 1 thereby start up the production of Repressor 1, switching off the other part of our switch by repressing Promoter 2. This will essentially make the cells change from red to green! This means that when the cells are exposed to Inducer 2, the cell culture will turn from green to red.