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A cell-based model for quorum sensing in heterogeneous bacterial colonies.

Melke, Pontus LU ; Sahlin, Patrik LU ; Levchenko, Andre and Jönsson, Henrik LU (2010) In PLoS Computational Biology 6(6).
Abstract
Although bacteria are unicellular organisms, they have the ability to act in concert by synthesizing and detecting small diffusing autoinducer molecules. The phenomenon, known as quorum sensing, has mainly been proposed to serve as a means for cell-density measurement. Here, we use a cell-based model of growing bacterial microcolonies to investigate a quorum-sensing mechanism at a single cell level. We show that the model indeed predicts a density-dependent behavior, highly dependent on local cell-clustering and the geometry of the space where the colony is evolving. We analyze the molecular network with two positive feedback loops to find the multistability regions and show how the quorum-sensing mechanism depends on different model... (More)
Although bacteria are unicellular organisms, they have the ability to act in concert by synthesizing and detecting small diffusing autoinducer molecules. The phenomenon, known as quorum sensing, has mainly been proposed to serve as a means for cell-density measurement. Here, we use a cell-based model of growing bacterial microcolonies to investigate a quorum-sensing mechanism at a single cell level. We show that the model indeed predicts a density-dependent behavior, highly dependent on local cell-clustering and the geometry of the space where the colony is evolving. We analyze the molecular network with two positive feedback loops to find the multistability regions and show how the quorum-sensing mechanism depends on different model parameters. Specifically, we show that the switching capability of the network leads to more constraints on parameters in a natural environment where the bacteria themselves produce autoinducer than compared to situations where autoinducer is introduced externally. The cell-based model also allows us to investigate mixed populations, where non-producing cheater cells are shown to have a fitness advantage, but still cannot completely outcompete producer cells. Simulations, therefore, are able to predict the relative fitness of cheater cells from experiments and can also display and account for the paradoxical phenomenon seen in experiments; even though the cheater cells have a fitness advantage in each of the investigated groups, the overall effect is an increase in the fraction of producer cells. The cell-based type of model presented here together with high-resolution experiments will play an integral role in a more explicit and precise comparison of models and experiments, addressing quorum sensing at a cellular resolution. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS Computational Biology
volume
6
issue
6
publisher
Public Library of Science
external identifiers
  • wos:000279341000025
  • pmid:20585545
  • scopus:77955490025
ISSN
1553-7358
DOI
10.1371/journal.pcbi.1000819
language
English
LU publication?
yes
id
023f5921-c44b-4712-ad4c-459a65e23d69 (old id 1625626)
date added to LUP
2010-07-21 13:04:56
date last changed
2018-06-24 03:25:03
@article{023f5921-c44b-4712-ad4c-459a65e23d69,
  abstract     = {Although bacteria are unicellular organisms, they have the ability to act in concert by synthesizing and detecting small diffusing autoinducer molecules. The phenomenon, known as quorum sensing, has mainly been proposed to serve as a means for cell-density measurement. Here, we use a cell-based model of growing bacterial microcolonies to investigate a quorum-sensing mechanism at a single cell level. We show that the model indeed predicts a density-dependent behavior, highly dependent on local cell-clustering and the geometry of the space where the colony is evolving. We analyze the molecular network with two positive feedback loops to find the multistability regions and show how the quorum-sensing mechanism depends on different model parameters. Specifically, we show that the switching capability of the network leads to more constraints on parameters in a natural environment where the bacteria themselves produce autoinducer than compared to situations where autoinducer is introduced externally. The cell-based model also allows us to investigate mixed populations, where non-producing cheater cells are shown to have a fitness advantage, but still cannot completely outcompete producer cells. Simulations, therefore, are able to predict the relative fitness of cheater cells from experiments and can also display and account for the paradoxical phenomenon seen in experiments; even though the cheater cells have a fitness advantage in each of the investigated groups, the overall effect is an increase in the fraction of producer cells. The cell-based type of model presented here together with high-resolution experiments will play an integral role in a more explicit and precise comparison of models and experiments, addressing quorum sensing at a cellular resolution.},
  articleno    = {e1000819},
  author       = {Melke, Pontus and Sahlin, Patrik and Levchenko, Andre and Jönsson, Henrik},
  issn         = {1553-7358},
  language     = {eng},
  number       = {6},
  publisher    = {Public Library of Science},
  series       = {PLoS Computational Biology},
  title        = {A cell-based model for quorum sensing in heterogeneous bacterial colonies.},
  url          = {http://dx.doi.org/10.1371/journal.pcbi.1000819},
  volume       = {6},
  year         = {2010},
}