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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

A plot comparing the relative abilities of cell populations with different total protein concentrations to accumulate about the peak of the ligand field for exponential shaped fields of differing steepness. In particular we consider here a steep (left, 10 − 1), intermediate (centre, 10 0) and shallow (right, 10 1) ligand gradient, where the x-axis values correspond to d in Eq. (2). Coloured lines show the final average distance from the peak ligand concentration achieved by each of the cell populations shown in Fig. 7. The colours of lines indicate the multiples (shown in the figure legend) of all total protein concentrations used in order to create different cell populations.
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f0040: A plot comparing the relative abilities of cell populations with different total protein concentrations to accumulate about the peak of the ligand field for exponential shaped fields of differing steepness. In particular we consider here a steep (left, 10 − 1), intermediate (centre, 10 0) and shallow (right, 10 1) ligand gradient, where the x-axis values correspond to d in Eq. (2). Coloured lines show the final average distance from the peak ligand concentration achieved by each of the cell populations shown in Fig. 7. The colours of lines indicate the multiples (shown in the figure legend) of all total protein concentrations used in order to create different cell populations.

Mentions: Firstly, it can be seen from Fig. 7, Fig. 8 that the different gradients result in very different ranges of behaviour. For example, in the shallow ligand gradient all cell populations appear to display a similar degree of accumulation whereas the intermediate and steep gradients display progressively larger differences in accumulation between different cell populations. This suggests that whilst some cell populations may perform better in shallower ligand gradients, the effect is likely to be small in comparison to the differences observed for steeper gradients.


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)

A plot comparing the relative abilities of cell populations with different total protein concentrations to accumulate about the peak of the ligand field for exponential shaped fields of differing steepness. In particular we consider here a steep (left, 10 − 1), intermediate (centre, 10 0) and shallow (right, 10 1) ligand gradient, where the x-axis values correspond to d in Eq. (2). Coloured lines show the final average distance from the peak ligand concentration achieved by each of the cell populations shown in Fig. 7. The colours of lines indicate the multiples (shown in the figure legend) of all total protein concentrations used in order to create different cell populations.
© Copyright Policy - CC BY
Related In: Results  -  Collection

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

f0040: A plot comparing the relative abilities of cell populations with different total protein concentrations to accumulate about the peak of the ligand field for exponential shaped fields of differing steepness. In particular we consider here a steep (left, 10 − 1), intermediate (centre, 10 0) and shallow (right, 10 1) ligand gradient, where the x-axis values correspond to d in Eq. (2). Coloured lines show the final average distance from the peak ligand concentration achieved by each of the cell populations shown in Fig. 7. The colours of lines indicate the multiples (shown in the figure legend) of all total protein concentrations used in order to create different cell populations.
Mentions: Firstly, it can be seen from Fig. 7, Fig. 8 that the different gradients result in very different ranges of behaviour. For example, in the shallow ligand gradient all cell populations appear to display a similar degree of accumulation whereas the intermediate and steep gradients display progressively larger differences in accumulation between different cell populations. This suggests that whilst some cell populations may perform better in shallower ligand gradients, the effect is likely to be small in comparison to the differences observed for steeper gradients.

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