Revision as of 12:20, 25 October 2008 by David.bikard (Talk | contribs)



Our project aims at biologically devising a “oscillating FIFO behaviour, synchronized at population level”. Such a setup will trigger periodic events and,therefore, can be considered as a “biological clock”. To completely deserve this appellation, the system has to fulfill the following specifications :

  • Oscillatory system : It will consist in providing a periodic output for the duration of the experiment. To do so, we will use a genetic cascade, initiated by a specific inducer which last step will inhibit the previously mentioned inducer.
  • FIFO System : The period of the oscillation is even more interesting if fit allows the sequential switching on and off of several genes. Our setup involves three genes which will get activated and desactivated successively as a “FIFO : First In, First Out”. This sequence is monitored by a logic structure called Feed-Forward Loop (FFL).
  • Synchronization : Yet, being able to control this sequential activation within a single cell can be seen as a “first step” in biological clock devising. In order to amplify this phenomenon (to observe it in an easier way or even to find future applications), it has to be extended to a whole population of bacteria. Here comes the synchronization issue: we will use methods based on the “quorum sensing” phenomenon.

We will base our project on an already existing structure, partly fulfilling the evoked specifications: the system that leads to the production of E. coli flagella.



First In First Out (FIFO) systems are present everywhere in nature from flux managment or electronics to genetic networks.


Oscillating FIFO

More details [PDF]

The 3 Modules