Team:UNAM-Genomics Mexico/fr/Project
From 2010.igem.org
Contents |
La Vision Générale
L'Idée
La Biologie Synthétique ouvre des nouvelles possibilités dans les domaines biologiques, telle la communication cellulaire. Dés son commencement et jusqu'à nous jours, celle-ci reposait sur le principe de la communication avec des messagers exclusivement chimiques. Ces messagers chimiques ont alors une portée limitée: même des messagers de portée assez longue comme les hormones, sont limités dans le système chimique qu'est le corps humain. Mais ce paradigme sera bientôt renversé.
Notre objectif dans ce projet s'agit de rendre la barrière chimique obsolète avec l'utilisation d'un messager non-chimique, c'est-à-dire des photons. Ceux-ci vont transporter l'information à communiquer entre des cellules spécialement modifiées équipées de deux habilitées: la perception et l'émission de la lumière. On va donc créer un nouvel système de photo-communication inter-cellulaire.
Nos messagers seront crées par des réactions de Bioluminescence, et ils seront assez capables de traverses des divers milieux. Logiquement, cela permet la propagation de l'information au-delà des restrictions chimiques, biologiques, et même spatiales. Du fait d'avoir un messager découplé du strate chimique, notre projet rend la communication assez facile entre des systèmes organiques, et des systèmes au silicium, tels les ordinateurs.
Le Nom
Vous avez sans doute reconnu le jeux de mots à l'origine du nom du projet. Le Wi-Fi est un standard de communication basé sur IEEE 802.11 très connu au monde. Non-officiellement, on pense Wi-Fi est né du Wireless Fidelity. Donc, parce que notre système permet la communication sans l'utilisation des fils, il est alors wireless. En ce qui concerne la fiabilité, on verra...
Or, avant de faire l'incursion au domaine du copyright, il faut clarifier deux aspects:
- Notre nom es WiFi, et non pas le Wi-Fi du [http://www.wi-fi.org/ Wi-Fi Alliance] (notez le trait d'union).
- D'autre part, une enquête rapide du [http://tess2.uspto.gov/ Système Électronique des Marques de Commerce], du Bureau des Patentes et des Marques de Commerce des États Unis a révèle que le mot WiFi était une marque de commerce en 2006, mais elle est listée comme "Morte" actuellement. C'est pour cela qu'on n'enfreint personne en utilisant WiFi.
Les Détails du Projet
On définit le phénomène de communication comme le transfert d'information par un moyen spécifique d'une entité émettrice à une entité réceptrice. Les entités biologiques
The process of transferring information from a sender entity to a receiver one through a determined channel is called communication. Biological entities have relied since time immemorial on chemical messengers to relay information; this holds true for multicellular organisms as well as for populations of unicellular organisms. Being chemical based, these messengers are constrained to a chemical system regardless of the scope of said system, eg: even far reaching messengers such as hormones are bound within the chemical system that is the human body.
In this project, our goal is to render the chemical barrier deprecated by enabling chemical-free communication. This has been translated to the implementation of a non-chemical messenger, in this case, photons. Our channel is thus light based; packages of photons, or energy quanta, will transport information from senders to receivers, effectively bypassing most chemical barriers in-between. Consequently, our communicating system is no longer contained within a chemical system, but within a physical one, ie: there must remain a physical channel where photons can be transported. This physical channel may range from something as sophisticated as a microcontroler-based electronic relay system, to something as simple as vacuum (or void). However, this physical layer proves very well to be impervious to most chemical signaling. Ergo, the chemical system's signaling would remain unaffected by the physical channel, and vice versa. In consequence, the exchange of information through physical means is sufficiently independent from the information encoded in the system's endogenous chemical pathways. In other words, it is extraordinarily uninvasive. As an added bonus, our receiver entities are easily transformed into emitter entities. Thus, by using our cells as information processing chassis, we can expand the communications layer. We can effectively render our system one where information is:
- Encoded and sent by an emitter
- Recieved and decoded by a receiver
- Plus processed, transformed, and relayed forth
Our ambicious implementation is based on well known systems, mainly bioluminescent proteins from Photinus pyralis and Vibrio fischeri, as well as photoactive receptors like Cyanobacteria cyanobacteriochromes and Light-Oxygen-Voltage domain quimeric proteins. We thus exploit the fact that cells already display primitive photo-communication, both within multicellular organisms as well as within populations of unicellular ones. Moreover, in our system the photonic information is transformed to and from chemical information within the chemical system that is an individual cell. Thus, the chemical barrier that is the membrane has ceased being a barrier to communication and is now a noise isolator. By decoupling the messenger from the chemical layer, we enable a brand new host of applications that were previously unavailable, ranging in domains from neurobiology, to cybernetic coupling, and even to biological telecommunications.
Reception
We plan on using a cyanobacteria phytochrome-like domain coupled to an EnvZ kinase to sense incoming red light and translate it into a signal detectable by the cell, in this case phosphorilated OmpR. This brilliant system was a construction known as [http://partsregistry.org/Coliroid Coliroid] for the 2004 iGEM by the University of Texas at Austin and UCSF iGEM team. This system acts as an <IF ! LIGHT> logic gate. We are contemplating the use of distinct assemblies to obtain a direct <IF LIGHT> logic gate.
Our second sensing device is based on another BioBrick Part: [http://partsregistry.org/Part:BBa_K191003 LOVtap]. This TF dimerizes when struck by blue light, thus activating the transcription of a determined promoter's coding sequence.
Our final input device is based on a newfound OmpR-like system of Synechocystis. This system uses a sensing protein (CcaS) than shows kinase activity when struck by green light. It then proceeds to phosphorilate a regulatroy TF (CcaR). This TF then starts transcription of its associated promoter's coding sequence.
Emission
We plan on using a mutated version of Photinus pyralis luciferase to generate red light. In addition, we will be using a newfound enzyme called Luciferin Regenerating Enzyme to recycle said substrate.
For the blue and green emissions, we will be using the Lux Operon from Vibrio fischeri. We plan on taking advantage of the lumazine BioBrick part to generate a blue-shifted light (around 450nm), as well as the LuxY of strain Y-1 to generate a red-shifted light (around 550nm).
Application
While glowing bacteria are nothing new, photo-communicating bacteria are something quite rare. We plan on using this advantage on several applications as a proof-of-principle. This may include an oscillator, a bio-cable, cell-phone-using bacteria, among others...
Results
(None yet... but check back soon!)