Fig 1.
Schematic of temporal and spatial sensing.
For temporal sensing, the cell compares the output at two different time points (left). For spatial sensing, the cell compares the ouput at its two ends (right).
Fig 2.
Steps in the computational modelling of network motifs.
Fig 3.
Temporal sensing is favored at high ratio of cell speed over cell size.
Percentage of runs where temporal sensing yield high output (green) or spatial sensing yield high output (red) for (a) incoherent feedforward and (b) negative integral feedback circuits at different values of β. The range of and
values used are
and
. (c) Dynamics of the average level of protein C (red), level of protein C at the front (green) and back (blue) for different values of β for the incoheret feedforward circuit with
. (d) Output from temporal (green) and spatial sensing (red) for the different values of β.
Fig 4.
Temporal sensing is favored over spatial sensing when diffusion rate of activator is higher than that of the inactivator.
(a,c) Fraction of parameters that choose temporal sensing over spatial sensing for different values of and
at β = 0.125 for the incoherent feedforward (a) and negative integral feedback circuits (c). (b,d) Dynamics of the average level of protein C (red), level of protein C at the front (green) and back (blue) for different values of
and
for the incoherent feedforward (b) and negative integral feedback circuits (d). OT and OS are the output from temporal and spatial sensing respectively.
Fig 5.
Choice of temporal versus spatial sensing.
(a) Parameter space for choice of temporal versus spatial sensing. (b) Plot of log(cell diameter, d) versus log(cell velocity, v) for chemotactic cells. The respective cells are as follows; In the flagellar group (green dots) are a: Vibriocholarae, b: Escherichia coli, c: Helicobacter pylori, d: Pseudomonas aeruginosa, e: Salmonella typhimurium, f: Marine Vibrioid bacteria sampled from Niva Bay, g: Thiovulum majus, h: Chlamydomonas reinhardtii, i: Sperm (human) and j: Sperm (Sea urchin). In the cilia group (blue diamonds) are k: Tetrahymena thermophila and l: Paramecium. In the lamellipodia/filopodia group (black stars) are m: T cell, n: Neutrophil, o: Hemocyte, p: B cell, q: Dendritic cell, r: Endothelial cell, s: Fibroblast and t: Border cells. In the pseudpodia group (red squares) are u: Dictyostelium discoideum, v: Acanthamoeba castellanii, w: Amoeba proteus and x: Chaos carolinensis. Assuming a signaling rate, lBC, occurring between 0.2s−1 to 5s−1 then the yellow region will be the separating boundary between cells with high and low values of β. The black line is the decision boundary for lBC = 1s−1.
Fig 6.
Noise in the external chemoattractant favors temporal sensing.
Results for the incoherent feedforward circuit (left) and negative integral feedback circuit (right). (a) Fraction of parameters that yielded OT > 0 (green) and OS > 0 (red) for all the stochastics runs at different amount of noise, η, for β = 0.25 (circle), β = 1.0 (diamonds) and β = 4.0 (triangles). (b) Fraction of parameters that chose temporal sensing (green), spatial sensing (red) and failure in sensing (black) at different amount of noise for β = 0.25 (first column), β = 1.0 (second column) and β = 4.0 (third column).
Fig 7.
Internal noise does not affect sensing choice.
Fraction of parameters that chose temporal sensing (green), spatial sensing (red) and failure in sensing (black) at different amount of noise, ν, for β = 0.25 (first column), β = 1.0 (second column) and β = 4.0 (third column) for incoherent feedforward circuit (a) and negative integral feedback circuit (b).
Fig 8.
Dynamics of the average level of protein C (red), level of protein C at the front (green) and back (blue) for noise in the external chemoattractant gradient (top) and internal signaling pathway (bottom).
Dotted lines are the average level of protein in the absence of any noise. Values used are β = 1.0, ,
and η = 1.0 (top) and ν = 0.25 (below).