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Understanding the link between single cell and population scale responses of Escherichia coli in differing ligand gradients.

Edgington MP, Tindall MJ - Comput Struct Biotechnol J (2015)

Bottom Line: We then study the response of cells in the presence of two different chemoattractants.In doing so we demonstrate that the population scale response depends not on the absolute concentration of each chemoattractant but on the sensitivity of the chemoreceptors to their respective concentrations.Our results show the clear link between single cell features and the overall environment in which cells reside.

View Article: PubMed Central - PubMed

Affiliation: Department of Mathematics & Statistics, University of Reading, Whiteknights, PO Box 220, Reading RG6 6AX, UK.

ABSTRACT
We formulate an agent-based population model of Escherichia coli cells which incorporates a description of the chemotaxis signalling cascade at the single cell scale. The model is used to gain insight into the link between the signalling cascade dynamics and the overall population response to differing chemoattractant gradients. Firstly, we consider how the observed variation in total (phosphorylated and unphosphorylated) signalling protein concentration affects the ability of cells to accumulate in differing chemoattractant gradients. Results reveal that a variation in total cell protein concentration between cells may be a mechanism for the survival of cell colonies across a wide range of differing environments. We then study the response of cells in the presence of two different chemoattractants. In doing so we demonstrate that the population scale response depends not on the absolute concentration of each chemoattractant but on the sensitivity of the chemoreceptors to their respective concentrations. Our results show the clear link between single cell features and the overall environment in which cells reside.

No MeSH data available.


Related in: MedlinePlus

Plots showing (left panel) the final locations of simulated E. coli cells and (right) the development in time of the average distance to the peak ligand concentration for each population. Results are shown for; (a) shallow; (b) intermediate; and (c) steep gradients. Each dot (left) refers to the final location of a single cell, whilst (right) lines show the average behaviour of a cell population in time. The different colours denote cell populations with different scaled total protein concentrations, i.e. those with β = 1/4 (grey), 1/2 (blue), 1 (red), 2 (green) 4 (black), 6 (pink), 8 (cyan) and 10 (gold). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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f0035: Plots showing (left panel) the final locations of simulated E. coli cells and (right) the development in time of the average distance to the peak ligand concentration for each population. Results are shown for; (a) shallow; (b) intermediate; and (c) steep gradients. Each dot (left) refers to the final location of a single cell, whilst (right) lines show the average behaviour of a cell population in time. The different colours denote cell populations with different scaled total protein concentrations, i.e. those with β = 1/4 (grey), 1/2 (blue), 1 (red), 2 (green) 4 (black), 6 (pink), 8 (cyan) and 10 (gold). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Mentions: To test this hypothesis we simulated the behaviour of 100 individual cells within each of the three ligand gradients shown in Fig. 4. Results obtained from these simulations are displayed in Fig. 7 (see Supplementary Video 1, Supplementary Video 2, Supplementary Video 3 for animations of each simulation).


Understanding the link between single cell and population scale responses of Escherichia coli in differing ligand gradients.

Edgington MP, Tindall MJ - Comput Struct Biotechnol J (2015)

Plots showing (left panel) the final locations of simulated E. coli cells and (right) the development in time of the average distance to the peak ligand concentration for each population. Results are shown for; (a) shallow; (b) intermediate; and (c) steep gradients. Each dot (left) refers to the final location of a single cell, whilst (right) lines show the average behaviour of a cell population in time. The different colours denote cell populations with different scaled total protein concentrations, i.e. those with β = 1/4 (grey), 1/2 (blue), 1 (red), 2 (green) 4 (black), 6 (pink), 8 (cyan) and 10 (gold). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660157&req=5

f0035: Plots showing (left panel) the final locations of simulated E. coli cells and (right) the development in time of the average distance to the peak ligand concentration for each population. Results are shown for; (a) shallow; (b) intermediate; and (c) steep gradients. Each dot (left) refers to the final location of a single cell, whilst (right) lines show the average behaviour of a cell population in time. The different colours denote cell populations with different scaled total protein concentrations, i.e. those with β = 1/4 (grey), 1/2 (blue), 1 (red), 2 (green) 4 (black), 6 (pink), 8 (cyan) and 10 (gold). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Mentions: To test this hypothesis we simulated the behaviour of 100 individual cells within each of the three ligand gradients shown in Fig. 4. Results obtained from these simulations are displayed in Fig. 7 (see Supplementary Video 1, Supplementary Video 2, Supplementary Video 3 for animations of each simulation).

Bottom Line: We then study the response of cells in the presence of two different chemoattractants.In doing so we demonstrate that the population scale response depends not on the absolute concentration of each chemoattractant but on the sensitivity of the chemoreceptors to their respective concentrations.Our results show the clear link between single cell features and the overall environment in which cells reside.

View Article: PubMed Central - PubMed

Affiliation: Department of Mathematics & Statistics, University of Reading, Whiteknights, PO Box 220, Reading RG6 6AX, UK.

ABSTRACT
We formulate an agent-based population model of Escherichia coli cells which incorporates a description of the chemotaxis signalling cascade at the single cell scale. The model is used to gain insight into the link between the signalling cascade dynamics and the overall population response to differing chemoattractant gradients. Firstly, we consider how the observed variation in total (phosphorylated and unphosphorylated) signalling protein concentration affects the ability of cells to accumulate in differing chemoattractant gradients. Results reveal that a variation in total cell protein concentration between cells may be a mechanism for the survival of cell colonies across a wide range of differing environments. We then study the response of cells in the presence of two different chemoattractants. In doing so we demonstrate that the population scale response depends not on the absolute concentration of each chemoattractant but on the sensitivity of the chemoreceptors to their respective concentrations. Our results show the clear link between single cell features and the overall environment in which cells reside.

No MeSH data available.


Related in: MedlinePlus