Sorting Bacteria

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=Intro=
=Intro=
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Two populations of bacteria with different clustering behavior and colors.
Two populations of bacteria with different clustering behavior and colors.
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=The Aggregation approach=
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=The "Aggregation" approach=
==Basic Idea==
==Basic Idea==
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The idea would be to have two types of E. coli :  
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The idea would be to have two types of E. coli : Type G would express GFP (they look green), other type R would express RFP (they look red)
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One type would express GFP (they look green)
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The starting material is an homogeneous mixture of red and green, i.e. of G- and R-type bacteria.
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The other type would express RFP (they look red)  
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The G-type bacteria would start, under induction, to express an aggregation factor, e.g. Antigen 43 (Ag43) working on stable media culture. Thus, the G-type bacteria would start to gather forming green dots on the plate.
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The R-type bacteria express their own aggregation factor (Ag43), but with a certain delay and thus leaving time to the G-type bacteria to sufficiently cluster first.
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The starting material is an unorganized mixture of red and green bacteria.  
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This would produce a sorting behavior, i.e. green bacteria surrounded by red bacteria the latter probably forming rings.
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=The "Chemotactical" Approach=
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==Basic Idea==
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If you want to get G-type cells to cluster into dots of specific sizes with belts of R-type cells around, maybe a more robust approach would be to make the G-type express a G-aggregation factor in parallel with a different quickly degrading substance Gs.
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The GFP expressing bacteria would start, under induction, to express Antigen 43 (Ag43)
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The R-type on the other hand exhibits chemotactical behavior for the same Gs, which will lead to  
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attraction of R-type cells by G-type cells.
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which is an aggregation factor working on stable media culture.  
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However, since the G-type cells tend to cluster together, the gradient will be stronger towards larger clusters. Thus, R-type individuals will stop following every other G-type cell and tend to aggregate to the larger G-type clusters.
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Since the R-type cells will form a belt of increasing size which will also function as a mechanical barrier for G-type cells, and since Gs is degrading rather quickly, the clusters as well as their surrounding belts will tend to have a specific size.
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The prerequisite of course is chemotactical behavior and thus sufficient mobility.
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The "green" bacteria would start to gather making green dots on the plates.  
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We think this would be an interesting self-organisation phenomena.
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The "red" bacteria express, with a certain delay(long enough to let the green ones to
 
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cluster first), the aggregation factor (Ag43).
 
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This would produce a sorted phenotype (green bacteria surrounded by red bacteria)
 
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==possible Extensions==
 
=Discussion=
=Discussion=
>> for comments, questions and temporary remarks go to the [[Talk:Sorting_Bacteria]]
>> for comments, questions and temporary remarks go to the [[Talk:Sorting_Bacteria]]
 +
 +
Back to [[Quorum_Sensing_based| Development Group]].
Back to [[ETH Zurich]] main page.
Back to [[ETH Zurich]] main page.

Latest revision as of 10:48, 7 August 2005

Back to ETH Zurich main page.

Back to Development Group.

Contents

Intro

Emergent sorting.

Principle

Two populations of bacteria with different clustering behavior and colors.

The "Aggregation" approach

Basic Idea

The idea would be to have two types of E. coli : Type G would express GFP (they look green), other type R would express RFP (they look red)

The starting material is an homogeneous mixture of red and green, i.e. of G- and R-type bacteria.

The G-type bacteria would start, under induction, to express an aggregation factor, e.g. Antigen 43 (Ag43) working on stable media culture. Thus, the G-type bacteria would start to gather forming green dots on the plate.

The R-type bacteria express their own aggregation factor (Ag43), but with a certain delay and thus leaving time to the G-type bacteria to sufficiently cluster first.

This would produce a sorting behavior, i.e. green bacteria surrounded by red bacteria the latter probably forming rings.

The "Chemotactical" Approach

Basic Idea

If you want to get G-type cells to cluster into dots of specific sizes with belts of R-type cells around, maybe a more robust approach would be to make the G-type express a G-aggregation factor in parallel with a different quickly degrading substance Gs.

The R-type on the other hand exhibits chemotactical behavior for the same Gs, which will lead to attraction of R-type cells by G-type cells.

However, since the G-type cells tend to cluster together, the gradient will be stronger towards larger clusters. Thus, R-type individuals will stop following every other G-type cell and tend to aggregate to the larger G-type clusters.

Since the R-type cells will form a belt of increasing size which will also function as a mechanical barrier for G-type cells, and since Gs is degrading rather quickly, the clusters as well as their surrounding belts will tend to have a specific size.

The prerequisite of course is chemotactical behavior and thus sufficient mobility.

We think this would be an interesting self-organisation phenomena.


Discussion

>> for comments, questions and temporary remarks go to the Talk:Sorting_Bacteria

Back to Development Group.

Back to ETH Zurich main page.

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