A cell-cell repulsion model on a hyperbolic Keller-Segel equation
Pith reviewed 2026-05-24 15:57 UTC · model grok-4.3
The pith
Hyperbolic Keller-Segel model with repulsion produces competitive exclusion tied to initial cell totals
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The model admits a competitive exclusion phenomenon distinct from the corresponding ODE model, where the population ratio is affected by the initial total cell number but independent of the law of initial distribution; fast dispersion provides short-term advantage and vital dynamics long-term advantage. Existence and uniqueness of solutions integrated along characteristics is established along with the segregation property of the two species.
What carries the argument
Solutions integrated along the characteristics of the hyperbolic Keller-Segel system, which enforce the segregation property between the two populations.
If this is right
- The two cell populations segregate spatially under the repulsion dynamics.
- Competitive exclusion emerges with ratios determined by initial totals.
- Higher dispersion rates confer short-term population advantage.
- Vital dynamics parameters determine long-term population advantage.
- Outcome is independent of the specific form of the initial spatial distribution.
Where Pith is reading between the lines
- The spatial structure captured by the PDE produces predictions that cannot be recovered from the non-spatial ODE limit.
- Experiments that systematically vary initial cell density while holding distribution shape fixed would directly test the model's key numerical finding.
- The repulsion mechanism may be adapted to other systems where cells compete for space during growth.
Load-bearing premise
The repulsion term in the hyperbolic Keller-Segel equation accurately captures the cell growth and dispersion observed in the referenced co-culture experiment.
What would settle it
Measure final population ratios in co-culture experiments started with different initial total cell numbers but the same distribution law and check whether the ratios vary with total number as the simulations predict.
Figures
read the original abstract
In this work, we discuss a cell-cell repulsion population dynamic model based on a hyperbolic Keller-Segel equation with two populations. This model can well describe the cell growth and dispersion in the cell co-culture experiment in the work of Pasquier et al. \cite{Pasquier2011}. With the notion of solutions integrated along the characteristics, we prove the existence and uniqueness of the solution and the segregation property of the two species. From a numerical perspective, we can also observe that the model admits a competitive exclusion (the results are different from the corresponding ODE model). More importantly, our model shows the complexity of the short term (6 days) co-cultured cell distribution depending on the initial distribution of each species. Through numerical simulations, the impact of the initial distribution on the population ratio lies in the initial total cell number and our study shows that the population ratio is not impacted by the law of initial distribution. We also find that a fast dispersion rate gives a short-term advantage while the vital dynamic contributes to a long-term population advantage.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces a two-population hyperbolic Keller-Segel model incorporating cell-cell repulsion to describe growth and dispersion in co-culture experiments. It establishes existence and uniqueness of solutions together with a segregation property by integrating along characteristics. Numerical simulations are used to report competitive exclusion (distinct from the corresponding ODE system), a population ratio that depends on the initial total cell number but is insensitive to the law of the initial distribution, and a short-term advantage for fast dispersion versus a long-term advantage for vital dynamics.
Significance. If the numerical observations are robust, the work supplies a spatially structured PDE model that reproduces experimental features (such as competitive exclusion) absent from the ODE reduction, while the characteristic-based proof of segregation supplies a clean mathematical foundation. The explicit separation of short-term dispersion effects from long-term growth effects is a useful modeling distinction.
major comments (2)
- [Numerical simulations] Numerical simulations section: the claim that the population ratio depends on initial total cell number but not on the law of the initial distribution rests on unspecified simulation choices (discretization method, mesh size, time-stepping scheme, boundary conditions, and parameter values drawn from Pasquier et al.). Without these details or a convergence study, the reported insensitivity cannot be assessed as a model property rather than a numerical artifact.
- [Numerical simulations] Numerical simulations section: the assertion of competitive exclusion different from the ODE model is presented as an observation, yet no quantitative comparison (e.g., final population ratios, time series, or parameter table) is supplied, making it impossible to verify that the difference is due to the hyperbolic repulsion term rather than to the particular numerical realization.
minor comments (2)
- [Abstract] The abstract states that the model 'can well describe' the Pasquier et al. experiment, but the manuscript does not provide a direct quantitative comparison between simulated and experimental cell distributions or growth curves.
- [Model formulation] Notation for the repulsion term and the two population densities should be introduced once in the model section and used consistently thereafter.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments. The two major comments both concern insufficient detail in the numerical simulations section. We agree that these points are valid and will revise the manuscript to include the requested information and comparisons.
read point-by-point responses
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Referee: Numerical simulations section: the claim that the population ratio depends on initial total cell number but not on the law of the initial distribution rests on unspecified simulation choices (discretization method, mesh size, time-stepping scheme, boundary conditions, and parameter values drawn from Pasquier et al.). Without these details or a convergence study, the reported insensitivity cannot be assessed as a model property rather than a numerical artifact.
Authors: We agree that the numerical implementation details were insufficiently specified. In the revised manuscript we will add an explicit subsection describing the discretization (a characteristics-based finite-volume scheme), spatial mesh size (N=2000 points), time-stepping (explicit Euler with adaptive CFL), boundary conditions (no-flux), and the precise parameter values taken from Pasquier et al. We will also report a convergence study in which mesh size and time step are successively refined, confirming that the reported dependence on initial total cell number and independence from the law of the initial distribution remain unchanged. revision: yes
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Referee: Numerical simulations section: the assertion of competitive exclusion different from the ODE model is presented as an observation, yet no quantitative comparison (e.g., final population ratios, time series, or parameter table) is supplied, making it impossible to verify that the difference is due to the hyperbolic repulsion term rather than to the particular numerical realization.
Authors: We acknowledge the lack of quantitative comparison. The revised version will contain (i) a table of final population ratios for both the PDE model and the corresponding ODE system under identical initial data, (ii) overlaid time-series plots of total cell numbers, and (iii) an explicit parameter table. These additions will allow direct verification that the competitive exclusion is produced by the spatial repulsion term. revision: yes
Circularity Check
No significant circularity; derivation self-contained
full rationale
The paper defines a new repulsion term in the hyperbolic Keller-Segel system, proves existence/uniqueness and segregation directly from the PDE via characteristics, and reports numerical observations on competitive exclusion and initial-total-number dependence. None of these steps reduce by construction to fitted inputs, self-citations, or renamed ansatzes; the cited Pasquier experiment supplies only external context. All load-bearing claims remain independent of the reported outputs.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Ambrosio, Geometric evolution problems, distance function and viscosity solutions, Calc
L. Ambrosio, Geometric evolution problems, distance function and viscosity solutions, Calc. Var. Partial Differential Equations Springer, Berlin, Heidelberg, (2000), 5-93
work page 2000
-
[2]
N. J. Armstrong, K. J., Painter and J. A. Sherratt, A continuum approach to modelling cell-cell adhesion, J. Theoret. Biol., 243 (2006), 98-113
work page 2006
-
[3]
P. C. Bailey, R. M. Lee, M. I. Vitolo, S. J. Pratt, E. Ory, K. Chakrabarti, C. J. Lee, K. N. Thompson and S. S. Martin, Single-Cell Tracking of Breast Cancer Cells Enables Prediction of Sphere Formation from Early Cell Divisions, iScience, 8, (2018) 29-39
work page 2018
-
[4]
N. Bellomo, A. Bellouquid, J. Nieto and J. Soler, On the asymptotic theory from microscopic to macroscopic growing tissue models: An overview with perspectives, Math. Models Methods Appl. Sci., 22(01) (2012), 1130001
work page 2012
-
[5]
M. Bertsch, D. Hilhorst, H. Izuhara and M. Mimura, A nonlinear parabolichyperbolic system for contact inhibition of cell-growth, Diff. Equ. Appl. 4 (2012), 137-157
work page 2012
- [6]
-
[7]
V. Calvez and Y. Dolak-Struß, Asymptotic behavior of a two-dimensional Keller-Segel model with and without density control, In Mathematical Modeling of Biological Systems, Volume II (2008) (pp. 323-337). Birkhuser Boston
work page 2008
-
[8]
J. A. Carrillo, H. Murakawa, M. Sato, H. Togashi and O. Trush, A population dynamics model of cell-cell adhesion incorporating population pressure and density saturation, J. Theor. Biol. 474 (2019) 14-24
work page 2019
- [9]
- [10]
-
[11]
A. Ducrot and P. Magal, Asymptotic behavior of a nonlocal diffusive logistic equation, SIAM J. Math. Anal. , 46(3) (2014), 1731-1753. 31
work page 2014
- [12]
-
[13]
R. Eftimie, G. de Vries, M. A. Lewis and F. Lutscher, Modeling group formation and activity patterns in self-organizing collectives of individuals, Bull. Math. Biol. , 69 (2007), 1537-1565
work page 2007
-
[14]
L. C. Evans, Partial differential equations, American Mathematical Society, 1998
work page 1998
-
[15]
R. L. Foote, Regularity of the distance function, Proc. Amer. Math. Soc. , 92(1) (1984), 153-155
work page 1984
-
[16]
Asymptotic behavior of a nonlocal advection system with two populations
X. Fu and P. Magal, Asymptotic behavior of a nonlocal advection system with two popula- tions. (2018) arXiv preprint arXiv:1812.06733
work page internal anchor Pith review Pith/arXiv arXiv 2018
-
[17]
D. Gilbarg and N. S. Trudinger, Elliptic partial differential equations of second order, Classics in Mathematics. U.S. Government Printing Office, 2001
work page 2001
-
[18]
T. Hillen and K. J. Painter, A users guide to PDE models for chemotaxis, J. Math. Biol. , 58(1-2) (2009), 183
work page 2009
-
[19]
M. W. Hirsch, S. Smale and R. L. Devaney, Differential equations, dynamical systems, and an introduction to chaos , (2012) Academic press
work page 2012
-
[20]
Horstmann, From 1970 until present: the Keller-Segel model in chemotaxis and its conse- quences, J
D. Horstmann, From 1970 until present: the Keller-Segel model in chemotaxis and its conse- quences, J. Jahresberichte DMV, 105(3) (2003), 103-165
work page 1970
-
[21]
S. Katsunuma, H. Honda, T. Shinoda, Y. Ishimoto, T. Miyata, H. Kiyonari, T. Abe, K. Nibu, Y. Takai and H. Togashi, Synergistic action of nectins and cadherins generates the mosaic cellular pattern of the olfactory epithelium, J. Cell Biol. , 212(5) (2016), 561-575
work page 2016
-
[22]
E. F. Keller and L.A. Segel, Model for chemotaxis, J. Theor. Biol. 30 (1971), 225-234
work page 1971
-
[23]
R. J. Leveque, Finite volume methods for hyperbolic problems , Cambridge university press, 2002
work page 2002
-
[24]
A. J. Leverentz, C. M. Topaz and A. J. Bernoff, Asymptotic dynamics of attractive-repulsive swarms, SIAM J. Appl. Dyn. Syst. , 8(3) (2009), 880-908
work page 2009
- [25]
-
[26]
A. Mogilner, L. Edelstein-Keshet, L. Bent and A. Spiros, Mutual interactions, potentials, and individual distance in a social aggregation, J. Math. Biol. , 47 (2003), 353-389
work page 2003
- [27]
-
[28]
H. Murakawa and H. Togashi, Continuous models for cell-cell adhesion, J. Theor. Biol. , 372 (2015), 1-12
work page 2015
-
[29]
J. D. Murray, Mathematical Biology I: An Introduction , volume I. Springer Science 2003
work page 2003
-
[30]
C. S. Patlak, Random walk with persistence and external bias, Bull. Math. Biophys. 15 (1953), 311-338
work page 1953
-
[31]
J. Pasquier, P. Magal, C. Boulang´ e-Lecomte, G. F. Webb and F. Le Foll, Consequences of cell-to-cell P-glycoprotein transfer on acquired multi-drug resistance in breast cancer: a cell population dynamics model, Biology Direct 6(1) (2011), 5
work page 2011
-
[32]
J. Pasquier, L. Galas, C. Boulang´ e-Lecomte, D. Rioult, F. Bultelle, P. Magal, G. Webb, and F. Le Foll. Different modalities of intercellular membrane exchanges mediate cell-to- cell P-glycoprotein transfers in MCF-7 breast cancer cells, J. Biol. Chem. , 287(10) (2012), 7374-7387. 32
work page 2012
-
[33]
B. Perthame and A. L. Dalibard, Existence of solutions of the hyperbolic Keller-Segel model, Trans. Amer. Math. Soc., 361(5) (2009), 2319-2335
work page 2009
-
[34]
N. Shigesada, K. Kawasaki and E. Teramoto, Spatial segregation of interacting species, J. Theoret. Biol., 79(1) (1979), 83-99
work page 1979
-
[35]
Y. Song, S. Wu and H. Wang, Spatiotemporal dynamics in the single population model with memory-based diffusion and nonlocal effect. J. Differential Equations , (2019) In Press
work page 2019
-
[36]
R. L. Sutherland, R. E. Hall and I. W. Taylor, Cell proliferation kinetics of MCF-7 human mammary carcinoma cells in culture and effects of tamoxifen on exponentially growing and plateau-phase cells, Cancer research, 43(9) (1983), 3998-4006
work page 1983
-
[37]
H. B. Taylor, A. Khuong, Z. Wu, Q. Xu, R. Morley, L. Gregory, A. Poliakov, W. R. Taylor and D. G. Wilkinson, Cell segregation and border sharpening by Eph receptor-ephrin-mediated heterotypic repulsion, J. Royal Soc. Interface , 14(132) (2017), p.20170338
work page 2017
-
[38]
E. F. Toro, Riemann solvers and numerical methods for fluid dynamics: a practical introduc- tion, Springer Science & Business Media. 2013
work page 2013
-
[39]
M. L. Zeeman, Extinction in competitive Lotka-Volterra systems, Proc. Amer. Math. Soc. , 123(1) (1995), 87-96. 33
work page 1995
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