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• Home
• Presentation
  • Overview
  • Potential applications
  • Collaborations
  • The team
  • Acknowledgements →
    • Host laboratory
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• Designs
  • Designs overview & concepts
  • Designs list
• Modeling
  • General overview
  • Modeling results for our designs →
    • The basics
    • Our assumptions
    • T7 polymerase diffusion
    • tRNA diffusion
    • ComK/ComS system
    • Parameters
  • Results of our passive diffusion model
  • Toward assisted diffusion
• Data
• Results
  • Achievements
  • Methodologies →
    • Microscopy
    • Micro-fluidic
    • Integration in B.subtilis
    • Kinetics
  • Parts list
  • Notebook
• Human practice & Safety
  • Human practice
  • Safety
  • Brainstorming
  • Bonus track

Our lab achievements

Preliminary experiments

In the Dubey and Ben-Yehuda paper [1] a set of simple experiments are made to prove the existence of the nanotubes. We tryied to reproduce some of them in order to demonstrate again the existence of these entities as a medium of communication between bacteria, and to be sure we are in the good experimental conditions to produce them and that we can go on with our designs.

We tryied to reproduce the two keystone experiments of the paper: the GFP diffusion, and the antibiotic resistance exchange, with less sucess for the latter.

	The GFP diffusion experiment is the simplest experiment possible. One Bacillus Subtlis strain that produce GFP is mixed with a wild type strain. If some nanotubes are formed, the GFP will diffuse through the tubes and color the non fluorescent strain. We invite you to visit corresponding the page to learn more about what we did and the results we had.
	The antibiotic resistance exchange is a more tricky experiment in which bacteria are shown to exchange resistance enzyme through nanotube and allow the population to survive even though all the cells does not carry the resistence.We invite you to visit corresponding the page to learn more about what we did and the results we had.

New devices

We designed entirely these new devices. They are usually composed of an emitter, a receptor and an amplifier subunit.

	The YFP concentrator This design relies on a TetO-array which allow us to concentrate YFP-TetR fusion proteins.
	T7 RNA polymerase diffusion In this design, we introduce the use of the T7 polymerase both as the transfer molecule and as the auto-amplification system.
	tRNA amber diffusion The tRNA amber is the smallest molecule we are trying to get pass the nanotubes . At the receiving end: T7 polymerase with two modified amber codons coupled with the T7 auto-amplifier and T7-driven GFP expression.

Using bistable switches

During our brainstormings, we noticed several natural or artificial bistable switches that could serve both as a receptor and an auto-amplifier. One molecule carefully chosen could toggle the switch in another position. All we have to do is see if it diffuses through the nanotubes.

	ComS diffusion We took advantage of a switch already existing in B.Subtilis (the ComK/ComS switch) and tried to see if we could toggle it from one state to the other using molecules diffusing through the nanotubes.
	Sin Operon We took advantage of a switch already existing in B.Subtilis (the Sin operon switch regulating sporulation and biofilm formation) and tried to see if we could toggle it from one state to the other using molecules diffusing through the nanotubes.