Tokyo/Requirements
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<!--==”共存安定”をなすために必要なこと==--> | <!--==”共存安定”をなすために必要なこと==--> | ||
| - | == What is necessary for " | + | == What is necessary for "Balanced differentiation"? == |
| - | The most important and underlying point of our model is that the system is stable against environmental changes when two types of individuals coexist, called " | + | The most important and underlying point of our model is that the system is stable against environmental changes when two types of differentiated individuals coexist, called "Balanced differentiation." Our project have aimed at this "Balanced differentiation" but not dynamic equilibrium such as chemical ones. |
<!--共存安定をなりたたせるために必要な要素は以下の３つである | <!--共存安定をなりたたせるために必要な要素は以下の３つである | ||
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２．Cell－Cellコミュニケーション | ２．Cell－Cellコミュニケーション | ||
３．２つの機能が１つの細胞から実現されること--> | ３．２つの機能が１つの細胞から実現されること--> | ||
| - | <br>To achieve this | + | <br>To achieve this “Balanced differentiation", our model requires |
<br>1. bistability at two distinct states in a single cell | <br>1. bistability at two distinct states in a single cell | ||
<br>2. cell-cell communication by quarum sensing | <br>2. cell-cell communication by quarum sensing | ||
| - | [[Image:Bistability.JPG|thumb|250px| '''Fig.1: Bistablity''' <br>Cells with the same gene take either of two states, A (worker, red) or B (idler, green) stably | + | [[Image:Bistability.JPG|thumb|250px| '''Fig.1: Bistablity''' <br>Cells with the same gene take either of two states, A (worker, red) or B (idler, green) stably.]] |
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'''~ at an individual level ~''' | '''~ at an individual level ~''' | ||
| - | For " | + | For "balanced differentiation" in our model, two types of cells should coexist stably. Therefore, cells with '''THE SAME GENE SET''' need to take either of '''TWO DIFFERENTIATED STATES''', A (Worker) or B (Idler) in our project as shown in Fig. 1. '''In order to distinguish from dynamic stability, "balanced differentiation" must be achieved by two distinct states inconvertible each other.''' |
<!--[[Image:collective.jpg|thumb|350px| '''Fig.2: Coexistence]]--> | <!--[[Image:collective.jpg|thumb|350px| '''Fig.2: Coexistence]]--> | ||
<!--<br>'''1-2. At a collective level''' | <!--<br>'''1-2. At a collective level''' | ||
<br> | <br> | ||
| - | To achieve " | + | To achieve "balanced differentiation", each cell needs to recognize cell types - the ratio of A and B - around itself. |
As is often the case in natural bacteria, our modified cells here sense the types of coexisting cells by cell-cell communication called quorum sensing. Under the coexistence of A and B at a specific ratio, the whole system (or group) is collectively stable. Fig. 2 simply shows this scheme. --> | As is often the case in natural bacteria, our modified cells here sense the types of coexisting cells by cell-cell communication called quorum sensing. Under the coexistence of A and B at a specific ratio, the whole system (or group) is collectively stable. Fig. 2 simply shows this scheme. --> | ||
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====2. Cell-cell communication ==== | ====2. Cell-cell communication ==== | ||
| - | When this | + | When this balanced differentiation is disrupted, by removing all the A type for example, these individual cells sense the change. Their states A or B become unstable as if cells became upset - '''INDIVIDUAL STATES ARE UNSTABLE ⇒ They are COLLECTIVELY UNSTABLE'''. Then some of them changed their states while the others do not. As a result, at a certain ratio of A and B again, the whole system comes back to a stable states. Here the cells are '''COLLECTIVELY STABLE ⇒ INDIVIDUALS ARE STABLE''' under this balanced differentiation. |
| - | [[Image:cellcell.jpg|thumb|450px| '''Fig.2: Cell-cell communication'''<br>Intercellular interaction is done by communication molecule AHL. When enough AHL is produced by the workers, the idlers are stable; however, if it is not ~ communication being interrupted, ~ they | + | [[Image:cellcell.jpg|thumb|450px| '''Fig.2: Cell-cell communication'''<br>Intercellular interaction is done by communication molecule AHL. When enough AHL is produced by the workers, the idlers are stable; however, if it is not ~ communication being interrupted, ~ they dedifferentiate. Thus, cells can sense the surrounding cell types. ]] |
Revision as of 19:20, 26 October 2007
Abstract Concept & Model Requirements Genetic_circuit Works About_our_team
What is necessary for "Balanced differentiation"?
The most important and underlying point of our model is that the system is stable against environmental changes when two types of differentiated individuals coexist, called "Balanced differentiation." Our project have aimed at this "Balanced differentiation" but not dynamic equilibrium such as chemical ones.
To achieve this “Balanced differentiation", our model requires
1. bistability at two distinct states in a single cell
2. cell-cell communication by quarum sensing
Cells with the same gene take either of two states, A (worker, red) or B (idler, green) stably.
1. Bistability
~ at an individual level ~
For "balanced differentiation" in our model, two types of cells should coexist stably. Therefore, cells with THE SAME GENE SET need to take either of TWO DIFFERENTIATED STATES, A (Worker) or B (Idler) in our project as shown in Fig. 1. In order to distinguish from dynamic stability, "balanced differentiation" must be achieved by two distinct states inconvertible each other.
2. Cell-cell communication
When this balanced differentiation is disrupted, by removing all the A type for example, these individual cells sense the change. Their states A or B become unstable as if cells became upset - INDIVIDUAL STATES ARE UNSTABLE ⇒ They are COLLECTIVELY UNSTABLE. Then some of them changed their states while the others do not. As a result, at a certain ratio of A and B again, the whole system comes back to a stable states. Here the cells are COLLECTIVELY STABLE ⇒ INDIVIDUALS ARE STABLE under this balanced differentiation.
Intercellular interaction is done by communication molecule AHL. When enough AHL is produced by the workers, the idlers are stable; however, if it is not ~ communication being interrupted, ~ they dedifferentiate. Thus, cells can sense the surrounding cell types.
