Team:Pretoria UP/Description

Project Description

Background to the Problem

Transcriptional switches form an integral part of synthetic biology. In the absence of positive feedback loops these systems are unstable since they require the maintained presence of a regulator. DNA switches based on heritable genetic modifications can allow for a permanent change in gene expression even in the absence of the initial signal. The Cre-Lox recombinase system from the P1 bacteriophage has been successfully used in genetic manipulation to excise targeted DNA fragments. Our aim is to use the Cre-Lox recombinase system to trigger a heritable genetic switch that allows for irreversible ON/OFF programming as an alternative to positive feedback loops. We are testing different approaches relying on the inversion and excision of lox-flanked DNA parts. Our long term goal is to integrate this system with signals from quorum sensing and a logic gate to program conditional chemotaxis in motile E. coli.