Cell-Based, Continuum and Hybrid Models of Tissue Dynamics
Abstract
Movement of amoeboid cells is involved in embryonic development, wound repair, the immune response to bacterial invasion, and tumor formation and metastasis. Individual cells detect extracellular chemical and mechanical signals via membrane receptors, and this initiates signal transduction cascades that produce intracellular signals. These signals control the motile machinery of the cell and thereby determine the spatial localization of contact sites with the substrate and the sites of force-generation needed to produce directed motion. The coordination and control of this complex process of direction sensing, amplification of spatial differences in the signal, assembly of the motile machinery, and control of the attachment to the substratum involves numerous molecules whose spatial distribution serves to distinguish the front from the rear of the cell, and whose temporal expression is tightly controlled. How chemical and mechanical signals are integrated, how spatial differences in signals are produced, and how propulsive and adhesive forces are controlled are issues that are amenable to mathematical modeling. An overview of some approaches to these complex problems is the subject of this chapter.
Keywords
Actin Filament Fruiting Body Actin Network Stochastic Simulation Algorithm Perfusion ExperimentReferences
- 1.B. Alberts, A. Johnson, J. Lewis, M. Raff, K. Roberts, P. Walter, Molecular Biology of the Cell, 4th edn. (Garland Science, New York, London, 2002)Google Scholar
- 2.U. Alon, M.G. Surette, N. Barkai, S. Leibler, Robustness in bacterial chemotaxis. Nature 15, 168–171 (1999)Google Scholar
- 3.R. Ananthakrishnan, A. Ehrlicher, The forces behind cell movement. Int. J. Biol. Sci. 3 (5), 303–17 (2007)CrossRefGoogle Scholar
- 4.L. Blanchoin, T.D. Pollard, Hydrolysis of ATP by polymerized actin depends on the bound divalent cation but not profilin. Biochemistry 41 (2), 597–602 (2002)CrossRefGoogle Scholar
- 5.D. Boal, Mechanics of the Cell (Cambridge University Press, Cambridge, 2002)Google Scholar
- 6.J.T. Bonner, The Cellular Slime Molds (Princeton University Press, Princeton, NJ, 1967)CrossRefGoogle Scholar
- 7.J.T. Bonner, A way of following individual cells in the migrating slugs of Dictyostelium discoideum. Proc. Natl. Acad. Sci. 95 (16), 9355–9359 (1998)CrossRefGoogle Scholar
- 8.D. Bray, Cell Movements: From Molecules to Motility (Garland Publishing, New York, 2001)Google Scholar
- 9.T. Bretschneider, K. Anderson, M. Ecke, A. Müller-Taubenberger, B. Schroth-Diez, H.C. Ishikawa-Ankerhold, G. Gerisch, The three-dimensional dynamics of actin waves, a model of cytoskeletal self-organization. Biophys. J. 96 (7), 2888–2900 (2009)CrossRefGoogle Scholar
- 10.J.A. Brzostowski, C.A. Parent, A.R. Kimmel, A Gα-dependent pathway that antagonizes multiple chemoattractant responses that regulate directional cell movement. Genes Dev. 18, 805–15 (2004)CrossRefGoogle Scholar
- 11.B. Bugyi, M.F. Carlier, Control of actin filament treadmilling in cell motility. Annu. Rev. Biophys. 39, 449–470 (2010)CrossRefGoogle Scholar
- 12.L. Cai, A.M. Makhov, D.A. Schafer, J.E. Bear, Coronin 1B antagonizes cortactin and remodels arp2/3-containing actin branches in lamellipodia. Cell 134 (5), 828–842 (2008)CrossRefGoogle Scholar
- 13.Y. Cao, H. Li, L. Petzold, Efficient formulation of the stochastic simulation algorithm for chemically reacting systems. J. Chem. Phys. 121 (9), 4059–67 (2004)CrossRefGoogle Scholar
- 14.M. Carlier, D. Pantaloni, E. Korn, The effects of Mg2+ at the high-affinity and low-affinity sites on the polymerization of actin and associated ATP hydrolysis. J. Biol. Chem. 261, 10785–10792 (1986)Google Scholar
- 15.L.B. Case, C.M. Waterman, Adhesive F-actin waves: a novel integrin-mediated adhesion complex coupled to ventral actin polymerization. PLoS One 6 (11), e26631 (2011)Google Scholar
- 16.M.Y. Chen, R.H. Insall, P.N. Devreotes, Signaling through chemoattracnt receptors in Dictyostelium. Trends Genet. 12 (2), 52–57 (1996)Google Scholar
- 17.H. Chen, B.W. Bernstein, J.R. Bamburg, Regulating actin-filament dynamics in vivo. Trends Biochem. Sci. 25 (1), 19–23 (2000). ReviewCrossRefGoogle Scholar
- 18.Y. Cheng, H.G. Othmer, A model for direction sensing in dictyostelium discoideum: Ras activity and symmetry breaking driven by a gβ γ- mediated, gα2-ric8 – dependent signal transduction network. PLoS Comput. Biol. 12, e1004900 (2016)CrossRefGoogle Scholar
- 19.C.Y. Chung, S. Funamoto, R.A. Firtel, Signaling pathways controlling cell polarity and chemotaxis. Trends Biochem. Sci. 26 (9), 557–566 (2001). ReviewCrossRefGoogle Scholar
- 20.J. Condeelis, A. Bresnick, M. Demma, S. Dharmawardhane, R. Eddy, A.L. Hall, R. Sauterer, V. Warren, Mechanisms of amoeboid chemotaxis: an evaluation of the cortical expansion model. Dev. Genet. 11 (5–6), 333–340 (1990)CrossRefGoogle Scholar
- 21.L.P. Cramer, M. Siebert, T.J. Mitchison, Identification of novel graded polarity actin filament bundles in locomoting heart fibroblasts: implications for the generation of motile force. J. Cell Biol. 136 (6), 1287–1305 (1997)CrossRefGoogle Scholar
- 22.J.C. Dallon, H.G. Othmer, A discrete cell model with adaptive signalling for aggregation of dictyostelium discoideum. Philos. Trans. R. Soc. Lond. B Biol. Sci. 352 (1351), 391–417 (1997)CrossRefGoogle Scholar
- 23.J.C. Dallon, H.G. Othmer, A continuum analysis of the chemotactic signal seen by dictyostelium discoideum. J. Theor. Biol. 194 (4), 461–483 (1998)Google Scholar
- 24.J.C. Dallon, H.G. Othmer, How cellular movement determines the collective force generated by the dictyostelium discoideum slug. J. Theor. Biol. 231, 203–222 (2004)MathSciNetCrossRefGoogle Scholar
- 25.P. Dancker, L. Hess, Phalloidin reduces the release of inorganic phosphate during actin polymerization. Biochim. Biophys. Acta 1035 (2), 197–200 (1990)CrossRefGoogle Scholar
- 26.L.A. Davidson, R.E. Keller, Neural tube closure in xenopus laevis involves medial migration, directed protrusive activity, cell intercalation and convergent extension. Development 126 (20), 4547–4556 (1999)Google Scholar
- 27.P.N. Devreotes, T.L. Steck, Cyclic 3′, 5′ AMP relay in Dictyostelium discoideum II. Requirements for the initiation and termination of the response. J. Cell Biol. 80, 300–309 (1979)Google Scholar
- 28.P.N. Devreotes, P.L. Derstine, T.L. Steck, Cyclic 3′, 5′ AMP relay in Dictyostelium discoideum I. A technique to monitor responses to controlled stimuli. J. Cell Biol. 80, 291–299 (1979)Google Scholar
- 29.G. DeYoung, P.B. Monk, H.G. Othmer, Pacemakers in aggregation fields of Dictyostelium disc oideum. Does a single cell suffice? J. Math. Biol. 26, 486–517 (1988)Google Scholar
- 30.D. Dormann, C.J. Weijer, Propagating chemoattractant waves coordinate periodic cell movement in dictyostelium slugs. Development 128 (22), 4535–4543 (2001)Google Scholar
- 31.D. Dormann, G. Weijer, C.A. Parent, P.N. Devreotes, C.J. Weijer, Visualizing PI3 kinase-mediated cell-cell signaling during dictyostelium development. Curr. Biol. 12 (14), 1178–1188 (2002)CrossRefGoogle Scholar
- 32.R.A. Firtel, R. Meili, Dictyostelium: a model for regulated cell movement during morphogenesis. Curr. Opin. Genet. Dev. 10 (4), 421–427 (2000). ReviewCrossRefGoogle Scholar
- 33.P. Friedl, K. Wolf, Tumour-cell invasion and migration: diversity and escape mechanisms. Nat. Rev. Cancer 3 (5), 362–74 (2003)CrossRefGoogle Scholar
- 34.I. Fujiwara, S. Takahashi, H. Tadakuma, S. Ishiwata, Microscopic analysis of polymerization dynamics with individual actin filaments. Nat. Cell. Biol. 4 (9), 666–673 (2002)CrossRefGoogle Scholar
- 35.C. Gadgil, C.H. Lee, H.G. Othmer, A stochastic analysis of first-order reaction networks. Bull. Math. Biol. 67, 901–946 (2005)MathSciNetCrossRefMATHGoogle Scholar
- 36.C.W. Gardiner, Handbook of Stochastic Methods (Springer, Berlin, Heildeberg, 1983)CrossRefMATHGoogle Scholar
- 37.G. Gerisch, Chemotaxis in dictyostelium. Annu. Rev. Physiol. 44 (1), 535–552 (1982)CrossRefGoogle Scholar
- 38.G. Gerisch, U. Wick, Intracellular oscillations and release of cyclic AMP from Dictyostelium cells. Biochem. Biophys. Res. Commun. 65, 364–370 (1975)CrossRefGoogle Scholar
- 39.G. Gerisch, D. Hulser, D. Malchow, U. Wick, Cell communication by periodic cyclic amp pulses. Philos. Trans. R. Soc. Lond. 272, 181–192 (1975)CrossRefGoogle Scholar
- 40.G. Gerisch, T. Bretschneider, A. Muler-Taubenberger, E. Simmeth, M. Ecke, S. Diez, K. Anderson, Mobile actin clusters and traveling waves in cells recovering from actin depolymerization. Biophys. J. 87 (5), 3493–3503 (2004)CrossRefGoogle Scholar
- 41.D.T. Gillespie, A general method for numerically simulating the stochastic time evolution of coupled chemical reactions. J. Comput. Phys. 22, 403–434 (1976)MathSciNetCrossRefGoogle Scholar
- 42.D.T. Gillespie, Exact stochastic simulation of coupled chemical reactions. J. Phys. Chem. 81 (25), 2340–2361 (1977)CrossRefGoogle Scholar
- 43.A.R. Gingle, Critical density for relaying in Dictyostelium discoideum and its relation to phosphodiesterase secretion into the extracellular medium. J. Cell Sci. 20, 1–20 (1976)Google Scholar
- 44.A.L. Hall, A. Schlein, J. Condeelis, Relationship of pseudopod extension to chemotactic hormone-induced actin polymerization in amoeboid cells. J. Cell Biol. 37 (3), 285–299 (1988)Google Scholar
- 45.B. Heit, S. Tavener, E. Raharjo, P. Kubes, An intracellular signaling hierarchy determines direction of migration in opposing chemotactic gradients. J. Cell Biol. 159 (1), 91–102 (2002)CrossRefGoogle Scholar
- 46.J. Hu, H.G. Othmer, A theoretical analysis of filament length fluctuations in actin and other polymers. J. Math. Biol. 63 (6), 1001–1049 (2011)MathSciNetCrossRefMATHGoogle Scholar
- 47.J. Hu, A. Matzavinos, H.G. Othmer, A theoretical approach to actin filament dynamics. J. Stat. Phys. 128 (1–2), 111–138 (2007)MathSciNetCrossRefMATHGoogle Scholar
- 48.J. Hu, H.W. Kang, H.G. Othmer, Stochastic analysis of reaction–diffusion processes. Bull. Math. Biol. 76, 854–894 (2014)MathSciNetCrossRefMATHGoogle Scholar
- 49.M. Iijima, Y.E. Huang, P. Devreotes, Temporal and spatial regulation of chemotaxis. Dev. Cell 3 (4), 469–478 (2002). ReviewCrossRefGoogle Scholar
- 50.K. Inouye, Measurement of the motive force of the migrating slug of dictyostelium discoideum by a centrifuge method. Protoplasma 121, 171–177 (1984)CrossRefGoogle Scholar
- 51.K. Inouye, I. Takeuchi, Analytical studies on migrating movement of the pseudoplasmodium of Dictyostelium Discoideum. Protoplasma 99, 289–304 (1979)Google Scholar
- 52.R.H. Insall, O.D. Weiner, PIP3, PIP2, and cell movement–similar messages, different meanings? Dev. Cell. 1 (6), 743–747 (2001)CrossRefGoogle Scholar
- 53.C. Janetopoulos, T. Jin, P. Devreotes, Receptor-mediated activation of heterotrimeric G-proteins in living cells. Science 291 (5512), 2408–2411 (2001)CrossRefGoogle Scholar
- 54.P.A. Janmey, Mechanical properties of cytoskeletal polymers. Curr. Opin. Cell Biol. 2, 4–11 (1991)CrossRefGoogle Scholar
- 55.T. Jin, N. Zhang, Y. Long, C.A. Parent, P.N. Devreotes, Localization of the G protein β γ complex in living cells during chemotaxis. Science 287 (5455), 1034–1036 (2000)CrossRefGoogle Scholar
- 56.H.W. Kang, L. Zheng, H.G. Othmer, A new method for choosing the computational cell in stochastic reaction–diffusion systems. J. Math. Biol. 60, 1017–1099 (2012)MathSciNetCrossRefMATHGoogle Scholar
- 57.H.W. Kang, L. Zheng, H.G. Othmer, A new method for choosing the computational cell in stochastic reaction-diffusion systems. J. Math. Biol. 60, 1017–1099 (2012)MathSciNetCrossRefMATHGoogle Scholar
- 58.V. Khamviwath, J. Hu, H.G. Othmer, A continuum model of actin waves in dictyostelium discoideum. PloS One 8 (5), e64272 (2013)Google Scholar
- 59.A.R. Kimmel, C.A. Parent, The signal to move: D. discoideum go orienteering. Science 300 (5625), 1525–1527 (2003)Google Scholar
- 60.J.R. Kuhn, T.D. Pollard, Real-time measurements of actin filament polymerization by total internal reflection fluorescence microscopy. Biophys. J. 88 (2), 1387–1402 (2005)CrossRefGoogle Scholar
- 61.D.A. Lauffenburger, A.F. Horwitz, Cell migration: a physically integrated molecular process. Cell 84, 359–369 (1996)CrossRefGoogle Scholar
- 62.A. Levchenko, P.A. Iglesias, Models of eukaryotic gradient sensing: application to chemotaxis of amoebae and neutrophils. Biophys. J. 82 (1 Pt 1), 50–63 (2002)CrossRefGoogle Scholar
- 63.L. Limozin, M. Barmann, E. Sackmann, On the organization of self-assembled actin networks in giant vesicles. Eur. Phys. J E 10 (4), 319–330 (2003)CrossRefGoogle Scholar
- 64.F.C. MacKintosh, Theoretical models of viscoelasticity of actin solutions and the actin cortex. Biol. Bull. 194 (3), 351–353 (1998). No abstract availableGoogle Scholar
- 65.A. Matzavinos, H.G. Othmer, A stochastic analysis of actin polymerization in the presence of twinfilin and gelsolin. J. Theor. Biol. 249 (4), 723–736 (2007)MathSciNetCrossRefGoogle Scholar
- 66.J.L. McGrath, E.A. Osborn, Y.S. Tardy, C.F. Dewey Jr, J.H. Hartwig, Regulation of the actin cycle in vivo by actin filament severing. Proc. Natl. Acad. Sci. USA 97 (12), 6532–7 (2000)CrossRefGoogle Scholar
- 67.S. McLaughlin, J. Wang, A. Gambhir, D. Murray, PIP2 and proteins: interactions, organization and information flow. Annu. Rev. Biophys. Biomol. Struct. 31, 151–175 (2002). ReviewCrossRefGoogle Scholar
- 68.R. Meili, C. Ellsworth, S. Lee, T.B. Reddy, H. Ma, R.A. Firtel, Chemoattractant-mediated transient activation and membrane localization of akt/PKB is required for efficient chemotaxis to cAMP in dictyostelium. EMBO J. 18 (8), 2092–2105 (1999)CrossRefGoogle Scholar
- 69.H. Meinhardt, Orientation of chemotactic cells and growth cones: models and mechanisms. J. Cell Sci. 17 (17), 2867–2874 (1999)Google Scholar
- 70.R. Melki, S. Fievez, M.F. Carlier, Continuous monitoring of pi release following nucleotide hydrolysis in actin or tubulin assembly using 2-amino-6-mercapto-7-methylpurine ribonucleoside and purine-nucleoside phosphorylase as an enzyme-linked assay. Biochemistry 35 (37), 12038–45 (1996)CrossRefGoogle Scholar
- 71.T.J. Mitchison, L.P. Cramer, Actin-based cell motility and cell locomotion. Cell 3, 371–379 (1996). Review. No abstract availableGoogle Scholar
- 72.F. Oosawa, S. Asakura, Thermodynamics of the Polymerization of Protein (Academic, New York, 1975)Google Scholar
- 73.H.G. Othmer, A graph-theoretic analysis of chemical reaction networks (1979). Lecture Notes, Rutgers University. Available at www.math.umn.edu/~othmer/graphrt.pdf
- 74.H.G. Othmer, P. Schaap, Oscillatory cAMP signaling in the development of dictyostelium discoideum. Comments Theor. Biol. 5, 175–282 (1998)Google Scholar
- 75.E. Palsson, H.G. Othmer, A model for individual and collective cell movement in dictyostelium discoideum. Proc. Natl. Acad. Sci. 97, 11448–11453 (2000)Google Scholar
- 76.C.A. Parent, P.N. Devreotes, A cell’s sense of direction. Science 284 (5415), 765–770 (1999). ReviewCrossRefGoogle Scholar
- 77.E. Pate, H.G. Othmer, Differentiation, cell sorting and proportion regulation in the slug stage of Dictyostelium discoideum. J. Theor. Biol. 118, 301–319 (1986)Google Scholar
- 78.M. Pineda, C. Weijer, R. Eftimie, Modelling cell movement, cell differentiation, cell sorting and proportion regulation in dictyostelium discoideum aggregations. J. Theor. Biol. 370, 135–150 (2015)MathSciNetCrossRefMATHGoogle Scholar
- 79.T.D. Pollard, Regulation of actin filament assembly by arp2/3 complex and formins. Annu. Rev. Biophys. Biomol. Struct. 36, 451–477 (2007)CrossRefGoogle Scholar
- 80.T.D. Pollard, L. Blanchoin, R.D. Mullins, Molecular mechanisms controlling actin filament dynamics in nonmuscle cells. Annu. Rev. Biophys. Biomol. Struct. 29 (1), 545–76 (2000)CrossRefGoogle Scholar
- 81.A.Y. Pollitt, R.H. Insall, WASP and SCAR/WAVE proteins: the drivers of actin assembly. J. Cell Sci. 122 (Pt 15), 2575–2578 (2009). doi: 10.1242/jcs.023879 CrossRefGoogle Scholar
- 82.R.K. Raman, Y. Hashimoto, M.H. Cohen, A. Robertson, Differentiation for aggregation in the cellular slime molds: the emergence of autonomously signalling cells in Dictyostelium discoideum. J. Cell. Sci. 21, 243–259 (1976)Google Scholar
- 83.D. Raucher, T. Stauffer, W. Chen, K. Shen, S. Guo, J.D. York, M.P. Sheetz, T. Meyer, Phosphatidylinositol 4,5-bisphosphate functions as a second messenger that regulates cytoskeleton-plasma membrane adhesion. Cell 100 (2), 221–228 (2000)CrossRefGoogle Scholar
- 84.J. Rosenblatt, P. Peluso, T.J. Mitchison, The bulk of unpolymerized actin in xenopus egg extracts is ATP-bound. Mol. Biol. Cell 6 (2), 227–36 (1995)CrossRefGoogle Scholar
- 85.K.R. Sanft, H.G. Othmer, Constant-complexity stochastic simulation algorithm with optimal binning. J. Chem. Phys. 143 (8), 074108 (2015)Google Scholar
- 86.P. Schaap, Evolutionary crossroads in developmental biology: dictyostelium discoideum. Development 138 (3), 387–396 (2011)CrossRefGoogle Scholar
- 87.D. Sept, J. Xu, T.D. Pollard, J.A. McCammon, Annealing accounts for the length of actin filaments formed by spontaneous polymerization. Biophys. J. 77 (6), 2911–2919 (1999)CrossRefGoogle Scholar
- 88.M.P. Sheetz, D. Felsenfeld, C.G. Galbraith, D. Choquet, Cell migration as a five-step cycle. Biochem. Soc. Symp. 65, 233–43 (1999)Google Scholar
- 89.F. Siegert, C.J. Weijer, Analysis of optical density wave propagation and cell movement in the cellular slime mould Dictyostelium discoideum 49, 224–232 (1991)Google Scholar
- 90.J.V. Small, Microfilament-based motility in non-muscle cells. Curr. Opin. Cell Biol. 1, 75–79 (1989)CrossRefGoogle Scholar
- 91.J.V. Small, T. Stradal, E. Vignal, K. Rottner, The lamellipodium: where motility begins. Trends Cell Biol. 12 (3), 112–120 (2002). ReviewCrossRefGoogle Scholar
- 92.D.R. Soll, The use of computers in understanding how animal cells crawl, in International Review of Cytology, vol. 163, ed. by K.W. Jeon, J. Jarvik (Academic, New York, 1995), pp. 43–104Google Scholar
- 93.P.A. Spiro, J.S. Parkinson, H.G. Othmer, A model of excitation and adaptation in bacterial chemotaxis. Proc. Natl. Acad. Sci. 94 (14), 7263–7268 (1997)CrossRefGoogle Scholar
- 94.T.M. Svitkina, G.G. Borisy, Arp2/3 complex and actin depolymerizing factor/cofilin in dendritic organization and treadmilling of actin filament array in lamellipodia. J. Cell Sci. 145(5), 1009–26 (1999)CrossRefGoogle Scholar
- 95.J. Swanson, D.L. Taylor, Local and spatially coordinated movements in D ictyostelium discoideum amoedae during chemotaxis. Cell 28, 225–232 (1982)CrossRefGoogle Scholar
- 96.Y. Tang, H.G. Othmer, A G protein-based model of adaptation in Dictyostelium discoideum. Math. Biosci. 120 (1), 25–76 (1994)Google Scholar
- 97.Y. Tang, H.G. Othmer, Excitation, oscillations and wave propagation in a G-protein-based model of signal transduction in Dictyostelium discoideum. Philos. Trans. R. Soc. Lond. B Biol. Sci. 349 (1328), 179–95 (1995)CrossRefGoogle Scholar
- 98.J.A. Theriot, T.J. Mitchison, Actin microfilament dynamics in locomoting cells. Nature 352 (6331), 126–131 (1991)CrossRefGoogle Scholar
- 99.A. Tikhonov, Systems of differential equations containing small parameters multiplying derivatives. Math. Sb. 31, 575–586 (1952)Google Scholar
- 100.P.H. Vardy, L.R. Fisher, E. Smith, K.L. Williams, Traction proteins in the extracellular matrix of Dictyostelium discoideum slugs. Nature 320 (6062), 526–529 (1986)CrossRefGoogle Scholar
- 101.B. Varnum, K.B. Edwards, D.R. Soll, Dictyostelium amebae alter motility differently in response to increasing versus decreasing temporal gradients of cAMP. J Cell Biol. 101, 1–5 (1985)CrossRefGoogle Scholar
- 102.B. Vasiev, C.J. Weijer, Modelling of dictyostelium discoideum slug migration. J. Theor. Biol. 223, 347–59 (2003)MathSciNetCrossRefGoogle Scholar
- 103.J.B. Wallingford, L.A. Niswander, G.M. Shaw, R.H. Finnell, The continuing challenge of understanding, preventing, and treating neural tube defects. Science 339 (6123), 1222002 (2013)Google Scholar
- 104.C.J. Weijer, Signalling during dictyostelium development, in Dictyostelids (Springer, Berlin, 2013), pp. 49–70Google Scholar
- 105.D. Wessels, J. Murray, D.R. Soll, Behavior of Dictyostelium amoebae is regulated primarily by the temporal dynamic of the natural cAMP wave. Cell Motil. Cytoskeleton 23 (2), 145–156 (1992)CrossRefGoogle Scholar
- 106.L. Wolpert, R. Beddington, T. Jessel, P. Lawrence, E. Meyerowitz, J. Smith, Principles of Development (Oxford University Press, Oxford, 2002)Google Scholar
- 107.B. Wurster, K. Schubiger, U. Wick, G. Gerisch, Cyclic GMP in Dictyostelium discoideum: oscillations and pulses in response to folic acid and cyclic AMP signals. FEBS Lett. 76, 141–144 (1977)CrossRefGoogle Scholar
- 108.X. Xin, H.G. Othmer, A trimer of dimers- based model for the chemotactic signal transduction network in bacterial chemotaxis. Bull. Math. Biol. 74, 2339–2382 (2012)MathSciNetCrossRefMATHGoogle Scholar
- 109.X.S. Xu, A. Kuspa, D. Fuller, W.F. Loomis, D.A. Knecht, Cell-cell adhesion prevents mutant cells lacking myosin II from penetrating aggregation streams of dictyostelium. Dev. Biol. 175 (2), 218–226 (1996)CrossRefGoogle Scholar
- 110.J. Xu, Y. Tseng, D. Wirtz, Strain hardening of actin filament networks. regulation by the dynamic cross-linking protein alpha-actinin. J. Biol. Chem. 275 (46), 35886–35892 (2000)Google Scholar
- 111.S.H. Zigmond, Recent quantitative studies of actin filament turnover during locomotion. Cell Motil. Cytoskeleton 25, 309–316 (1993)CrossRefGoogle Scholar