IGEM:IMPERIAL/2006/project/Oscillator/project browser/Prey Construct/Design

 Specifications Design Modelling Implementation Testing/Validation  

Registry

 * The prey part: J37015 @ MIT Parts Registry



Design Choices

 * Design must fulfil the specifications for the prey construct.
 * Part design will be based on Quorum-sensing/quenching and the availability of BioBricks.
 * Research into the registry directed us to use AHL as our prey molecule.


 * Design allows for an exponential increase of AHL (to fulfil the Lotka-Volterra model) via a positive feedback loop.
 * The prey part can be decoupled into a prey sensing part and a prey producing part.
 * Initiation of positive feedback loop depends on leaky expression of the tetR promoter which is a constitutive promoter.
 * This leaky expression produces LuxR which can form a dimer with AHL already withing the cell.
 * LuxR, AHL and promoter control the expression of LuxI which produces AHL.
 * Design allows for assesment of status of positive feedback loop via:
 * GFP Production - Linked to LuxI expression
 * AHL Production - Can be indirectly assessed according to J37015 protocol.

Open Issues

 * We need to consider methods of controlling the positive feedback loop while cells are growing to ensure AHL concentration stays at zero. Possible suggestions are:
 * Periodic dilution of culture to allow degradation of LuxI
 * Riboswitch
 * Pops blocker

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