From 2007.igem.org

The Company

Mukund: Chief Mentor, Consultant and The Godfather Sugat Right-hand Man and Manager of Operations Nilesh The Man for all Seasons Vivek Chief Troubleshooter, often his role is confused with one of a Troublemaker Krishna: The Sharpshooter Senthil: The Wikiman, also fondly referred to as the "Bio Info God" Varun: The Voice of Reason and Anti-Reason K12Z1: The Workhorse

The Mission

To investigate multistability and hysteresis in combinatorially constructed synthetic Vibrio quorum sensing circuits

The Target - Vibrio Quorum Sensing System

Quorum sensing is a phenomenon by which bacteria sense a critical cell density before turning on the expression of certain genes. It involves the gradual build-up of a chemical termed the 'autoinducer' in the cell. The autoinducer freely diffuses across the cell membrane and hence, its concentration is population density dependent. When the concentration crosses a threshold, the bacteria switch to a different physiological state such as bioluminescence, virulent gene expression, and bio-film formation.

In Vibrio fischeri, when the population density (and hence the concentration of autoinducer) crosses a certain threshold, the expression of a set of genes that is required for bioluminescence is turned on. The production of the autoinducer is under the control of a gene, the expression of which involves positive feedback. The following figure shows the various components of this system (Ref. 1).