Team:Cambridge/turingpatterns

Research of the previous Team's work

iGEM Mexico 2007

• Project Failed
• Admitted were underfunded, no results shown

iGEM Mexico 2009

• Apparently 11 out of 12 ligations were successful - they would have been able to test the system had the final ligation occurred.
• The only experimental results were those demonstrating that AHL was initiating it's own transcription via the expression of GFP.
• Seemed to have done quite a lot of good modelling work. So will be difficult to go much further on this aspect of the project

iGEM 2008 Cambridge team - iBrain

• Planned to use similar quorum sensing mechanisms with the lux operon to detect activity. However, the lux operon would not work in a gram positive organism such as Bacillus therefore only E.coli could work.

Own Research

Papers on Turing Patterns

• Original paper from Alan Turing: http://www.dna.caltech.edu/courses/cs191/paperscs191/turing.pdf

Further information

• Different signalling mechanisms have a large amount of cross-talk in bacteria
• The ACL Transcription factor is very specific initially but when bound becomes very non-specific, therefore cannot use two distinct systems in the same bacteria expressing different outputs in the same bacteria, instead 2 different strains would have to be used. This was the reason why a predator-prey model worked in a previous study.
• In the proposed system, there would be an activator and an inhibitor, with different diffusion rates due to the chain length of the molecules. The activator would be a short chain molecule and the inhibitor a long chain molecule so that the inhibitor diffuses slowly.
• One suggestion is that metabolites could be used as the morphogens in this system, for example metabolites that release or free another signalling molecule from the media, e.g. Arabinose - http://en.wikipedia.org/wiki/Arabinose.
• Another suggestion was peptide signalling, which uses an AGR-like system. There are 4 proteins, a pre-peptide, a processing, secreting and supporting peptide, and 2 sensing peptides.

Advantages of the Turing Project

• A new quorum sensing molecular system could be added to the registry which if a proven system could be easily applied to other systems. This would stand alone as an achievement no matter what the other successes or failures.

Conclusion

• Turing patterns have been well described theoretically
• Mexico 2009 modelled the problem extensively
• Our project WILL have to reach the implementation stage to go a step further
• Some Biobricks exist. A lot of the project will have to do with fine tuning of the system
• Combine with one of the other projects? Bioluminescence?