Sorting Bacteria
From 2006.igem.org
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.
