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Cell Biophysics

, Volume 11, Issue 1, pp 177–238 | Cite as

The cytoskeletal mechanics of brain morphogenesis

Cell state splitters cause primary neural induction
  • Richard Gordon
  • G. Wayne Brodland
Article

Abstract

There is a functional device in embryonic ectodermal cells that we propose causes them to differentiate into either neuroepithelial or epidermal tissue during the process called primary neural induction. We call this apparatus the “cell state splitter”. Its main components are the apical microfilament ring and the coplanar apical mat of microtubules, which exert forces in opposite radial directions. We analyze the mechanical interaction between these cytoskeletal components and show that they are in anunstable mechanical equilibrium. The role of the cell state splitter is thus to create a mechanical instability corresponding to the embryonic state of “competence” in an otherwise mechanically stable cell. When the equilibrium of the cell state splitter is disturbed so as to produce a slight contraction of the apical end, apical contraction continues and the distinctive columnar neuroepithelial cells are produced. A slight expansion from the equilibrium state, on the other hand, results in flattened epidermal cells. The calculated forces are consistent with the know constitutive and force-generating properties and morphology of microfilaments and microtubules, and with free tubulin concentration. There are no free parameters in the analysis.

The first cells to assume the neuroepithelial state lie over the notochord. Propagation of the neuroepithelial state (homoiogenetic induction) then proceeds via stretch-induced constriction of the apical microfilament rings, until ahemisphere is covered, at which point the high rate of change of the meridional stress component necessary for further propagation vanishes. The remaining cells are stretched somewhat by this process and become epidermis. A sharp boundary between the tissues is thus formed (explaining “compartmentalization” and the binary nature of differentiation in general).

Normal induction apparently involves setup of the cell state splitters in all of the ectoderm cells, perhaps synchronously timed by global embryo tension. The initial transition of cells from the ectodermal to the neuroepithelial state begins at the notoplate, where cell attachments to the notochord may both cause basal actin deposition and significantly reduce the stress induced in the ectoderm by the global tension, biasing the notoplate cell state splitters toward the neuroepithelial state. Introduction of an organizer or other solid substrate (artificial inducer) elsewhere, to which ectodermal cells can adhere, may likewise have both of these effects.

Differentiation to either epidermis or neuroepithelium is thus a machanical eventfollowed by the synthesis of specific proteins. This model of differentiation suggests that the genome responds to, rather than directly causes, differentiation.

Index Entries

Primary neural induction neurulation cytoskeleton microfilaments microtubules morphogenesis differentiation compartmentalization cell state splitter biomechanics embryology 

Abbreviations

MAP

microtubule associated protein

mRNA

messenger ribonucleic acid

MTOC

microtubule organizing centre

N-CAM

neural cell adhesion molecule

RNA

ribonucleic acid

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References

  1. 1.
    Kuhn, T. S. (1970),The Structure of Scientific Revolutions. 2nd ed., University of Chicago Press, Chicago.Google Scholar
  2. 2.
    Spemann, H., and H. Mangold (1924), Über Induktion von Embryonal-anlagan durch Implantation artfremder Organisatoren.Arch. Mikr. Anat. Entw. Mech. 100, 599–638.CrossRefGoogle Scholar
  3. 3.
    Spemann, H. (1938),Embryonic Development and Induction. reprint, 1967, Hafner, New York.Google Scholar
  4. 4.
    Hamburger, U. (1985), Hans Spemann (Nobel Laureate 1935).Trends Neurosci. 8(9), 385–387.CrossRefGoogle Scholar
  5. 5.
    Hamburger, U., and Edsall, J. T. (1984), Hilde Mangold, co-discoverer of the organizer.J. Hist. Biol. 17(1), 1–11.PubMedCrossRefGoogle Scholar
  6. 6.
    Nieuwkoop P. D., Johnen, A. G., and Albers B. (1985),The Epigenetic Nature of Early Chordate Development: Inductive Interaction and Competence. Cambridge University Press, Cambridge.Google Scholar
  7. 7.
    Needham J., Waddington C. H., and Needham, D. M. (1934), Physicochemical experiments on the amphibian organizer.Proc. Roy. Soc. B114, 393–422.Google Scholar
  8. 8.
    Needham J. (1936),Order and Life, MIT Press, Cambridge, MA.Google Scholar
  9. 9.
    Saxén, L., and Toivonen, S. (1962),Primary Embryonic Induction. Logos Press, London.Google Scholar
  10. 10.
    Nakamura O., and Toivonen, S. eds. (1978),Organiser—A Milestone of a Half-Century from Spemann. Elsevier/North Holland, Amsterdam.Google Scholar
  11. 11.
    Witkowski, J. (1985), The hunting of the organizer: an episode in biochemical embryology,Trends Biochem. Sci. 10(10), 379–381.CrossRefGoogle Scholar
  12. 12.
    Twitty V. C. (1966),Of Scientists and Salamanders, Freeman, San Francisco, CA.Google Scholar
  13. 13.
    Holtfreter, J. (1933), Nachweis der Induktionsfähigkeit abgetöteter Keimteile.Arch. EntwMech. Org. 128, 584–633.CrossRefGoogle Scholar
  14. 14.
    Holtfreter, J. (1934), Ueber die Verbreitung induzierender Substanzen und ihre Leistungen imTriton-Keim.Arch. EntwMech. Org. 132, 307–383.CrossRefGoogle Scholar
  15. 15.
    Youn, B. W., and Malacinski, G. M. (1981), Axial structure development in ultraviolet-irradiated (notochord-defective) amphibian embryos.Dev. Biol. 83, 339–352.PubMedCrossRefGoogle Scholar
  16. 16.
    Brun, R. B., and Garson J. A. (1984), Notochord formation in the Mexican salamander (Ambystoma mexicanum) is different from notochord formation inXenopus laevis.J. Exp. Zool. 229(2), 235–240.CrossRefGoogle Scholar
  17. 17.
    Saxén, L. (1961), Transfilter neurel induction of amphibian ectoderm.Dev. Biol. 3, 140–152.PubMedCrossRefGoogle Scholar
  18. 18.
    Saxén, L., McKinnell, R. G., Diberardino, M. A., Blumenfeld, M., and Bergad, R. D., eds. (1980),Differentiation and Neoplasia. Springer-Verlag, Berlin, 147–154.Google Scholar
  19. 19.
    Nyholm, M., Saxén, L., Toivonen, S. and Vainio, T. (1962), Electron microscopy of transfilter neural induction.Exp. Cell Res. 28, 209–212.PubMedCrossRefGoogle Scholar
  20. 20.
    Gallera, J. (1967), L’induction neurogène chez les Oiseaux: passage du flux inducteur par le filtre millipore.Experientia 23, 461–462.CrossRefGoogle Scholar
  21. 21.
    Gallera J., Nicolet, G., and Baumann, M. (1968), Induction neurale chez les Oiseaux à travers un filtre millipore: étude au microscope optique et électronique [Neural induction in birds through a Millipore filter: study by optical and electron microscopy].J. Embryol. Exp. Morph. 19(3), 439–450.PubMedGoogle Scholar
  22. 22.
    Toivonen, S., Tarin, D., Saxén, L., Tarin, P. J., and Wartiovaara, J. (1975), Transfilter studies on neural induction in the newt.Differentiation 4, 1–7.PubMedCrossRefGoogle Scholar
  23. 23.
    Toivonen, S., and Wartiovaara, J. (1976), Mechanisms of cell interaction during primary neural induction studied in transfilter experiments.Differentiation 5, 61–66.PubMedCrossRefGoogle Scholar
  24. 24.
    Toivonen, S. (1979), Transmission problem in primary induction.Differentiation 15, 177–181.PubMedCrossRefGoogle Scholar
  25. 25.
    Wartiovaara, J., Lehtonen, E., Nordling, S., and Saxén, L. (1972), Do membrane filters prevent cell contacts?Nature 238, 407–408.CrossRefGoogle Scholar
  26. 26.
    England, M. A. (1975), Membrane filters do not prevent, cell contacts.Experientia 31(3), 349–351.PubMedCrossRefGoogle Scholar
  27. 27.
    Gurdon, J. B. (1987), Embryonic induction—molecular prospects.Development 99(3), 285–306.PubMedGoogle Scholar
  28. 28.
    Burnside, B. (1972), Experimental induction of microfilament formation and contraction,J. Cell Biol. 55, 33aGoogle Scholar
  29. 29.
    Beloussov, L. V. (1980), The role of tensile fields and contact cell polarization in the morphogenesis of amphibian axial rudiments.Wilhelm Roux’ Arch. Dev. Biol. 188, 1–7.CrossRefGoogle Scholar
  30. 30.
    Weiss, P. (1953), Summary comments at the conclusion of the symposium.Arch. Neerland. Zool. 10(Suppl.), 165–176.Google Scholar
  31. 31.
    Nieuwkoop, P. D. (1985), Inductive interaction and determination; a new approach to an old problem.Molecular Determinants of Animal Form. Alan R. Liss, New York, 59–71.Google Scholar
  32. 32.
    Holtfreter, J. (1968), Mesenchyme and epithelia in inductive and morphogenetic processes. Fleischmajer, R., and Billingham, R. E., eds.,Epithelial-Mesenchymal Interactions. Williams & Wilkins, Baltimore, 1–30.Google Scholar
  33. 33.
    Nieuwkoop, P. D., et al. (1955) Origin and establishment of organization patterns in embryonic fields during embryonic development in amphibians and birds, in particular in the nervous system and its substrate.Proc. Acad. Sci. Amst. C58, 219–367.Google Scholar
  34. 34.
    Bellairs, R. (1959), The development of the nervous system in chick embryos.J. Embryol. Exp. Morph. 7(1), 94–115.PubMedGoogle Scholar
  35. 35.
    Johnen, A. G. (1956), Experimental studies about the temporal relationships in the induction process 1. Experiments onAmblystoma mexicanum.Koninkl. Nederl. Akad. Van Wetenschappen Proc. Ser. C,59, 554–660.Google Scholar
  36. 36.
    Kurihara, K., and Sasaki, N. (1981), Transmission of homoiogenetic induction in presumptive ectoderm of newt embryo.Dev. Growth Diff. 23, 361–369.CrossRefGoogle Scholar
  37. 37.
    Burnside, B., and Jacobson, A. G. (1968), Analysis of morphogenetic movements in the neural plate of the newtTaricha torosa.Dev. Biol. 18, 537–552.PubMedCrossRefGoogle Scholar
  38. 38.
    Tarin, D. (1971), Scanning electron microscopical studies of the embryonic surface during gastrulation and neurulation inXenopus laevis.J. Anat. 109, 535–547.PubMedGoogle Scholar
  39. 39.
    Suzuki, A. S., and Miki, K. (1983), Cellular basis of neuralization of induced neurectoderm in amphibian embryogenesis: changes of cell shape, cell size, and cytodifferentiation of the neurectoderm after neural induction.Dev. Growth Differ. 25, 289–297.CrossRefGoogle Scholar
  40. 40.
    Nieuwkoop, P. D., and Faber, J. (1975),Normal Table of Xenopus laevis (Daudin). 2nd ed. North Holland, Amsterdam.Google Scholar
  41. 41.
    Jacobson, A. G., and Gordon, R. (1976), Changes in the shape of the developing vertebrate nervous system analyzed experimentally, mathematically and by computer simulation.J. Exp. Zool. 197, 191–246.PubMedCrossRefGoogle Scholar
  42. 42.
    Gordon, R., and Jacobson, A. G. (1978), The shaping of tissues in embryos.Sci. Am. 238(6), 106–113.PubMedCrossRefGoogle Scholar
  43. 43.
    Messier, P.-E. (1978), Microtubules, interkinetic nuclear migration and neurulation.Experientia (Basel),34(3), 289–296.Google Scholar
  44. 44.
    Nagele, R. G., and Lee, H.-Y. (1979), Ultrastructural changes in cells associated with interkinetic nuclear migration in the developing chick neuroepithelium.J. Exp. Zool. 210(1), 89–106.PubMedCrossRefGoogle Scholar
  45. 45.
    Schoenwolf, G. C. (1982), On the morphogenesis of the early rudiments of the developing central nervous system.Scanning Electron Microsc. 1982(1), 289–308.Google Scholar
  46. 46.
    Schoenwolf, G. C. (1986), On the morphogenesis of the early rudiments of the developing central nervous system. Schoenwolf, G. C., ed.Scanning Electron Microscope Studies of Embryogenesis. Scanning Electron Microscopy, AMF O’Hare, IL,1986, 97–116.Google Scholar
  47. 47.
    Hara, K. (1961),Regional Neural Differentiation Induced by Prechordal and Presumptive Chordal Mesoderm in the Chick Embryo, University of Utrecht, Holland. PhD thesis.Google Scholar
  48. 48.
    England, M. A. (1973), The occurrence of a band of nuclei in primary neural inductions in the chick embryo.Experientia 29(10), 1267–1268.PubMedCrossRefGoogle Scholar
  49. 49.
    Kühn, A. (1971),Lectures on Developmental Physiology 2nd ed. Springer-Verlag, New York.Google Scholar
  50. 50.
    Burnside, B. (1971), Microtubules and microfilaments in newt neurulation.Dev. Biol. 26, 416–441.PubMedCrossRefGoogle Scholar
  51. 51.
    Lazarides, E. (1980), Intermediate filaments as mechanical integrators of cellular space.Nature 283, 249–256.PubMedCrossRefGoogle Scholar
  52. 52.
    Godsave, S. F., Anderton, B. H., and Wylie, C. C. (1986), The appearance and distribution of intermediate filament proteins during differentiation of the central nervous system, skin and notochord ofXenopus laevis.J. Embryol. Exp. Morph. 97, 201–223.PubMedGoogle Scholar
  53. 53.
    Tapscott, S. J., Bennett, G. S., and Holtzer, H. (1981), Neuronal precursor cells in the chick neural tube express neurofilament proteins.Nature,292, 836–838.PubMedCrossRefGoogle Scholar
  54. 54.
    Burnside, B. (1973), Microtubules and microfilaments in amphibian neurulation.Amer. Zool. 13, 989–1006.Google Scholar
  55. 55.
    Jonas, E., Sargent, T. D., and Dawid, I. B. (1985), Epidermal keratin gene expressed in embryos ofXenopus laevis.Proc. Natl. Acad. Sci. USA 82, 5413–5417.PubMedCrossRefGoogle Scholar
  56. 56.
    Godsave, S. F., Wylie, C. C., Lane, E. B., and Anderton, B. H. (1984), Intermediate filaments in theXenopus oocyte: the appearance and distribution of cytokeration-containing filaments.J. Embryol. Exp. Morph. 83, 157–167.PubMedGoogle Scholar
  57. 57.
    Suzuki, A. S., Ueno, T., and Matsusaka, T. (1986), Alteration of cell adhesion system in amphibian ectoderm cells during primary embryonic induction: changes in reaggregation pattern of induced neurectoderm cells and ultrastructural features of the reaggregate.Roux’s Arch. Dev. Biol. 195, 85–91.CrossRefGoogle Scholar
  58. 58.
    Jacobson, M., and Rutishauser U. (1986), Induction of neural crest cell adhesion molecule (NCAM) inXenopus embryos.Dev. Bio. 116, 524–531.CrossRefGoogle Scholar
  59. 59.
    Kintner, C. R., and Melton, D. A. (1987), Expression of Xenopus N-CAM RNA in ectoderm as an early response to neural induction.Development 99(3), 311–320.PubMedGoogle Scholar
  60. 60.
    Jaffe, L. F. (1985), Extracellular current measurements with a vibrating probeTrends Neurosci. 8(12), 517–521.CrossRefGoogle Scholar
  61. 61.
    Regen, J., and Steinhardt, R. (1986), Global properties ofXenopus blastulae are mediated by a high resistance epithelial seal.Dev. Biol.,113, 147–154.CrossRefGoogle Scholar
  62. 62.
    Slack, J. M. W. (1984), The early amphibian embryo—a hierarcly of developmental decisions. Malacinski, G. M. and S. V. Bryant, eds.,Pattern Formation, A Primer in Developmental Biology. Macmillan, New York, 457–480.Google Scholar
  63. 63.
    Gordon, R. (1983), A model for primary neural induction.Modulation of Cell Function, Abstracts of Western Winter Workshop in Cell Biology. Canadian Society for Cell Biology.Google Scholar
  64. 64.
    Warner, A. E. (1985), Factors controlling the early development of the nervous system. Edelman, G. M., Gall, W. E., Cowan, W. M., eds.,Molecular Bases of Neural Development. Wiley, New York, 11–34.Google Scholar
  65. 65.
    Dustin, P. (1984),Microtubules. 2nd ed. Springer-Verlag, Berlin.Google Scholar
  66. 66.
    Matsumoto, G., Ichikawa, M., Tasaki, A., Murofushi, H., and Sakai, H. (1984) Axonal microtubules necessary for generation of sodium current in squid giant axons. I. Pharmacological study on sodium current and restoration of sodium current by microtubule proteins and 260 K protein.J. Membrane Biol. 77, 77–93.CrossRefGoogle Scholar
  67. 67.
    Matsumoto, G., Ichikawa, M., and Tasaki, A. (1984), Axonal microtubules necessary for generation of sodium current in squid giant axons. II. Effect of colchicine upon asymmetrical displacement current.J. Memb. Biol. 77, 93–101.CrossRefGoogle Scholar
  68. 68.
    Alvarez, J., and Ramirez, B. U. (1979), Axonal microtubules: their regulation by the electrical activity of the nerve.Neurosci. Lett. 15, 19–22.PubMedCrossRefGoogle Scholar
  69. 69.
    Slack, J. M. W. (1985), Peanut lectin receptors in the early amphibian embryo: regional markers for the study of embryonic induction.Cell,41, 237–247.PubMedCrossRefGoogle Scholar
  70. 70.
    Slack, J. M. W. (1984), Regional biosynthetic markers in the early amphibian embryo.J. Embryol. Exp. Morph. 80, 289–319.PubMedGoogle Scholar
  71. 71.
    Takata, K., Yamamoto, K. Y., and Ozawa, R. (1981), Use of lectins as probes for analysing embryonic induction.Wilhelm Roux’ Arch. Dev. Biol. 190, 92–96.CrossRefGoogle Scholar
  72. 72.
    Takata, K., Yamamoto, K. Y., Ishii, I., and Takahashi, N. (1984), Glyco-of proteins responsive to the neural-inducing effect of convavalin A in Cynops presumptive ectoderm.Cell Differen. 14, 25–31.CrossRefGoogle Scholar
  73. 73.
    Duprat, A. M., Kan, P., Gualandris, L., Foulquier, F., Marty, J., and Weber, M. (1985), Neural induction: embryonic determination elicits full expression of specific neuronal traits.J. Embryol. Exp. Morphs.,89, (Suppl.), 167–183.Google Scholar
  74. 74.
    Baker, P. C., and Schroeder, T. E. (1967), Cytoplasmic filaments and morphogenetic movements in the amphibian neural tube.Dev. Biol. 15, 432–450.PubMedCrossRefGoogle Scholar
  75. 75.
    Waddington, C. H., and Perry, M. M. (1966), A note on the mechanism of cell deformation in the neural folds in the amphibia.Exp. Cell Res. 41, 691–693.PubMedCrossRefGoogle Scholar
  76. 76.
    Karfunkel, P. (1974), The mechanism of neural tube formation.Int. Rev. Cytol. 38, 245–271.PubMedGoogle Scholar
  77. 77.
    Gordon, R. (1983), Computational embryology of the vertebrate nervous system. Geisow, M., and Barrett, A., eds.Computing in Biological Science. Elsevier, Amsterdam, 23–70.Google Scholar
  78. 78.
    Gordon, R. (1985), A review of the theories of vertebrate neurulation and their relationship to the mechanics of neural tube birth defects.J. Embryol. Exp. Morph. 89 (Suppl.), 229–255.PubMedGoogle Scholar
  79. 79.
    Grant, P. (1978),Biology of Developing Systems, Holt, Rinehart and Winston, New York.Google Scholar
  80. 80.
    Wakely, J., and Badley, R. A. (1982), Organization of actin filaments in early chick embryo ectoderm: an ultrastructural and immunocytochemical study.J. Embryol. Exp. Morph. 69, 169–182.PubMedGoogle Scholar
  81. 81.
    Handel, M. A., and Roth, L. E. (1971), Cell shape and morphology of the neural tube: implications for microtubule function.Dev. Biol. 25, 78–95.PubMedCrossRefGoogle Scholar
  82. 82.
    Burnside, M. B. (1976), Possible roles of microtubules and actin filaments in retinal pigmented epithelium.Exp. Eye Res. 23(2), 257–275.PubMedCrossRefGoogle Scholar
  83. 83.
    Kendall, M. G., and Moran, P. A. P. (1963),Geometrical Probability. Hafner, New York.Google Scholar
  84. 84.
    Hill, T. L., and Kirschner, M. W. (1982), Subunit treadmilling of microtubules or actin in the presence of cellular barriers: possible conversion of chemical free energy into mechanical work.Proc. Natl. Acad. Sci. USA 79, 490–494.PubMedCrossRefGoogle Scholar
  85. 85.
    Hill, T. L., and Kirschner, M. W. (1982), Bioenergietics and kinetics of microtubule and actin filament assembly-disassembly.Int. Rev. Cytol. 78, 1–125.PubMedGoogle Scholar
  86. 86.
    Weiss, D. G., and Gross, G. W. (1983), Intracellular transport in axonal microtubular domains I. Theoretical considerations on the essential properties of a force generating mechanism.Protoplasma,114, 179–197.CrossRefGoogle Scholar
  87. 87.
    Gross, G. W., and Weiss, D. G. (1983), Intracellular transport in axonal microtubular domains II. Velocity profile and energetics of circumtubular flow.Protoplasma 114, 198–209.CrossRefGoogle Scholar
  88. 88.
    Schliwa, M. (1986),The Cytoskeleton: An Introductory Survey. Springer-Verlag, Wien.Google Scholar
  89. 89.
    Tucker, J. B., and Meats, M. (1976), Microtubules and control of insect egg shape.J. Cell. Biol. 71 (1), 207–217.PubMedCrossRefGoogle Scholar
  90. 90.
    Fach, B. L., Graham, S. F., and Keates, R. A. B. (1986), Association of microtubules with membrane skeletal proteins.Ann. NY Acad. Sci. 466, 843–845.PubMedCrossRefGoogle Scholar
  91. 91.
    Hill, T. L., and Carlier, M.-F. (1983), Steady-state theory of the interference of GTP hydrolysis in the mechanisms of microtubule assembly.Proc. Natl. Acad. Sci. USA 80, 7234–7239.PubMedCrossRefGoogle Scholar
  92. 92.
    Carlier, M.-F., Hill, T. L., and Chen, Y.-D. (1984), Interference of GTP hyrolysis in the mechanism of microtubule assembly: an experimental study.Proc. Natl. Acad. Sci. USA 81, 771–775.PubMedCrossRefGoogle Scholar
  93. 93.
    Mitchison, T., and Kirschner, M. (1984), Dynamic instability of microtubule growth.Nature 312, 237–242.PubMedCrossRefGoogle Scholar
  94. 94.
    Kirschner, M. W., and Mitchison, T. (1986), Microtubule dynamics.Nature,324, 621.PubMedCrossRefGoogle Scholar
  95. 95.
    Horio, T., and Hotani, H. (1986), Visualization of the dynamic instability of individual microtubules by dark-field microscopy.Nature,321, 605–607.PubMedCrossRefGoogle Scholar
  96. 96.
    Schulze, E., and Kirschner, M. (1987), Dynamic and stable populations of microtubules in cells.J. Cell. Biol. 104, 277–288.PubMedCrossRefGoogle Scholar
  97. 97.
    Kirschner, M. W., and Mitchison, T. J. (1986), Beyond self-assembly: from microtubules to morphogenesis.Cell 45, 329–342.PubMedCrossRefGoogle Scholar
  98. 98.
    Stevens, J. K., and Trogadis, J. T. (1984), Computer-assisted reconstruction from serial electron micrographs: a tool for the systematic study of neuronal form and function.Adv. Cell. Neurobiol. 5, 341–369.Google Scholar
  99. 99.
    Tsukita, S., and Ishihawa, H. (1981), The cytoskeleton in myelinated axons: serial section study.Biomed. Res. 2, 424–437.Google Scholar
  100. 100.
    Warren, R. H. (1974), Microtubular organization in elongating myogenic cells.J. Cell Biol. 63, 550–566.PubMedCrossRefGoogle Scholar
  101. 101.
    Warren, R. H., and Burnside B. (1978), Microtubules in cone myoid elongation in the teleost retina.J. Cell Biol. 78(1), 247–259.PubMedCrossRefGoogle Scholar
  102. 102.
    Olmsted, J. B., Marcum, J. M., Johnson, K. A., Allen, C., and Borisy, G. G. (1974) Microtubule assembly: some possible regulatory mechanisms.J. Supramol. Struct. 2, 429–450.PubMedCrossRefGoogle Scholar
  103. 103.
    Regula, C. S., Pfeiffer, J. R., and Berlin, R. D. (1981), Microtubule assembly and disassembly at alkaline pH.J. Cell. Biol. 89, 45–53.PubMedCrossRefGoogle Scholar
  104. 104.
    Purich, D. L., and Kristofferson, D. (1984), Microtubule assembly: a review of progress, principles, and perspectives.Adv. Protein Chem. 36, 133–212.PubMedCrossRefGoogle Scholar
  105. 105.
    Pipeleers, D. G., Pipeleers-Marichal, M. A., Sherline, P., and Kipnis, D. M. (1977), A sensitive method for measuring polymerized and depolymerized forms of tubulin in tissues.J. Cell Biol. 74, 341–350.PubMedCrossRefGoogle Scholar
  106. 106.
    Pipeleers, D. G., Pipeleers-Marichal, M. A., and Kipnis, D. M. (1977), Physiological regulation of total tubulin and polymerized tubulin in tissues.J. Cell Biol. 74, 351–357.PubMedCrossRefGoogle Scholar
  107. 107.
    Olmsted, J. B. (1981), Tubulin pools in differentiating neuroblastoma cells.J. Cell Biol. 89, 418–423.PubMedCrossRefGoogle Scholar
  108. 108.
    Lasek, R. J., and Morris, J. R. (1982), The microtubule-neurofilament network: the balance between plasticity and stability in the nervous system. Sakai, H., Mohri, H., and Borisy, G. G., eds.Biological Functions of Microtubules and Related Structures. Academic Press, Tokyo, 329–342.Google Scholar
  109. 109.
    Raff, E. C. (1977), Microtubule proteins in axolotl eggs and developing embryos.Dev. Biol. 58, 56–75.PubMedCrossRefGoogle Scholar
  110. 110.
    Schreckenberg, G. M., and Jacobson, A. G. (1975), Normal stages of development of the axolotl,Ambystoma mexicanum.Dev. Biol. 42, 391–400.PubMedCrossRefGoogle Scholar
  111. 111.
    Forgue, S. T., and Dahl, J. L. (1978), The turnover rate of tubulin in rat brain.J. Neurochem. 31, 1289–1297.PubMedCrossRefGoogle Scholar
  112. 112.
    Caron, J. M., Jones, A. L., and Kirschner, M. W. (1985), Autoregulation of tubulin synthesis in hepatocytes and fibroblasts.J. Cell Biol. 101, 1763–1772.PubMedCrossRefGoogle Scholar
  113. 113.
    Gall, L., Picheral, B., and Gounon, P. (1983), Cytochemical evidence for the presence of intermediate filaments and microfilaments in the egg ofXenopus laevis.Biol. Cell,47, 331–342.Google Scholar
  114. 114.
    Godsave, S. F., Anderton, B. H., Heasman, J., and Wyle, C. C. (1984), Oocytes and early embryos ofXenopus laevis contain intermediate filaments which react with anti-mammalian vimentin antibodies.J. Embryol. Exp. Morph.,83, 169–187.PubMedGoogle Scholar
  115. 115.
    Yamazaki, S., Maeda, T., and Miki-Noumura, T. (1982), Flexural rigidity of singlet microtubules estimated from statistical analysis of flucluating images. Sakai, H., Mohri, H., and Borisy, G. G., eds.Biological Functions of Microtubules and Related Structures. Academic Press, Tokyo, 41–48.Google Scholar
  116. 116.
    Mizushima-Sugano, J., Maeda, T., and Miki-Noumura, T. (1983), Flexeral rigidity of singlet microtubules estimated from statistical analysis of their contour lengths and end-to-end distances.Biochim. Biophys. Acta 755(2), 257–262.PubMedGoogle Scholar
  117. 117.
    Hirokawa, N. (1982), Cross-linker system between neurofilaments, microtubules, and membranous organelles in frog axons revealed by the quick-freeze, deep-etching method.J. Cell Biol. 94, 129–142.PubMedCrossRefGoogle Scholar
  118. 118.
    Bloom, G. S., Luca, F. C., and Vallee, R. B. (1985), Cross linking of intermediate filaments to microtubules by microtubule associated protein-2.Ann. N.Y. Acad. Sci. 455, 18–31.PubMedCrossRefGoogle Scholar
  119. 119.
    Williams, R. C., Jr., and Aamodt, E. J. (1985), Interactions between microtubules and neurofilamentsin vitro.Ann. NY Acad. Sci. 455, 509–524.PubMedCrossRefGoogle Scholar
  120. 120.
    Timoshenko, S. P., and Gere, J. M. (1961),Theory of Elastic Stability. 2nd ed. McGraw-Hill, New York.Google Scholar
  121. 121.
    Fulton, A. B. (1982), How crowded is the cytoplasm?Cell,30, 345–347.PubMedCrossRefGoogle Scholar
  122. 122.
    Lin, J. J. C., and Feramisco, J. R. (1981), Disruption of the in vivo distribution of the intermediate filaments in fibroblasts through the microinjection of a specific monoclonal antibody.Cell 24, 185–193.PubMedCrossRefGoogle Scholar
  123. 123.
    Blose, S. H., Meltzer, D. I., and Feramisco, J. R. (1984), 10-nm filaments are induced to collapse in living cells microinjected with monoclonal and polyclonal antibodies against tubulin.J. Cell Biol. 98, 847–858.PubMedCrossRefGoogle Scholar
  124. 124.
    Jockusch, B. M., Füchtbauer, A., Wiegand, C., and Höner, B. (1986), Probing the cytoskelton by microinjection. Shay, J. W., ed.,Cell and Molecular Biology of the Cytoskeleton. Plenum, New York, 1–40.Google Scholar
  125. 125.
    Nagele, R. G., and Lee, H.-Y. (1980) Studies on the mechanism of neurulation in the chick: microfilament-mediated change in cell shape during uplifting of neural folds.J. Exp. Zool. 213(1), 391–398.CrossRefGoogle Scholar
  126. 126.
    Owaribe, K., Kodama, R., and Eguchi, G. (1981), Demonstration of contractility of circumferential actin bundles and its morphogenetic significance in pigmented epitheliumin vitro andin vivo.J. Cell Biol. 90, 507–514.PubMedCrossRefGoogle Scholar
  127. 127.
    Lee, H.-Y., and Nagele, R. G. (1985), Studies on the mechanisms of neurulation in the chick: interrelationship of contractile proteins, microfilaments, and the shape of neuroepithelial cells.J. Exp. Zool. 235(2), 205–215.PubMedCrossRefGoogle Scholar
  128. 128.
    Schroeder, T. E. (1973), Cell constriction: contractile role of microfilaments in division and development.Amer. Zool. 13, 949–960.Google Scholar
  129. 129.
    Fujiwara, K., and Pollard, T. D. (1976), Fluorescent antibody localization of myosin in the cytoplasm, cleavage furrow, and mitotic spindle of human cells.J. Cell Biol. 71, 848–875.PubMedCrossRefGoogle Scholar
  130. 130.
    Rappaport, R. (1967), Cell division: direct measurement of maximum tension exerted by furrow of echinoderm eggs.Science,156, 1241–1243.PubMedCrossRefGoogle Scholar
  131. 131.
    Yoneda, M., and Dan, K. (1972), Tension at the surface of the dividing sea-urchin egg.J. Exp. Biol. 57, 575–587.PubMedGoogle Scholar
  132. 132.
    Hiramoto, Y. (1975), Force exerted by the cleavage furrow of sea urchin eggs.Dev. Growth Differ.17(1), 27–38.CrossRefGoogle Scholar
  133. 133.
    Hiramoto, Y. (1979), Mechanical properties of the dividing sea urchin egg. Hatano, S., Ishikawa, H., and Sato, H., eds.Cell Motility: Molecules and Organization. University Park Press, Baltimore, 653–663.Google Scholar
  134. 134.
    Rappaport, R. (1977), Tensiometric studies of cytokinesis in cleaving sand dollar eggs.J. Exp. Zool. 201, 375–378.PubMedCrossRefGoogle Scholar
  135. 135.
    Nakamura, S., and Hiramoto, Y. (1978), Mechanical properties of the cell surface in starfish eggs.Develop. Growth Differ. 20(4), 317–327.CrossRefGoogle Scholar
  136. 136.
    Schroeder, T. E. (1972), The contractile ring II. Determining its brief existence, volumetric changes, and vital role in cleavingArbacia eggs.J. Cell Biol. 53, 419–434.PubMedCrossRefGoogle Scholar
  137. 137.
    Schroeder, T. E. (1975), Dynamics of the contractile ring. Inoué, S., and Stephens, R. E., eds.,Molecules and Cell Movement. Raven Press, New York, 305–334.Google Scholar
  138. 138.
    Guyton, A. C. (1981),Textbook of Medical Physiology. 6th ed. Saunders, Philadelphia.Google Scholar
  139. 139.
    Huxley, H. E. (1960), Muscle cells. Brachet, J., and Mirsky, A. E., eds.,The Cell. Academic Press, New York,4, 365–481.Google Scholar
  140. 140.
    Vick, R. L. (1984),Contemporary Medical Physiology. Addison-Wesley, Menlo Park, CA.Google Scholar
  141. 141.
    Bayliss, W. M. (1902), On the local reaction of the arterial wall to changes of internal pressure.J. Physiol. (Lond.) 28, 220–231.Google Scholar
  142. 142.
    Johnsson, B. (1984) Myogenic responses of vascular smooth muscle. Stephens, N. L., ed.Smooth Muscle Contraction. Dekker, New York, 457–472.Google Scholar
  143. 143.
    Burnside, B. (1973), In vitro elongation of isolated neural plate cells: possible roles of microtubules and contractility.J. Cell Biol. 50, 41a.Google Scholar
  144. 144.
    Odell, G. M., Oster, G., Alberch, P., and Burnside, B. (1981), The mechanical basis of morphogenesis. I. Epithelial folding and invagination.Dev. Biol. 85, 446–462.PubMedCrossRefGoogle Scholar
  145. 145.
    Stanisstreet, M., and Jumah H. (1983), Calcium, microfilaments and morphogenesis.Life Sci. 33(15), 1433–1441.PubMedCrossRefGoogle Scholar
  146. 146.
    Perry, M. M., and Waddington, C. H. (1966), Ultrastructure of the blastopore cells in the newt.J. Embryol. Exp. Morph. 15, 317–330.PubMedGoogle Scholar
  147. 147.
    Cooke, J. (1975) Local autonomy of gastrulation movements after dorsal lip removal in two anuran amphibians.J. Embryol. Exp. Morph. 33, 147–157.PubMedGoogle Scholar
  148. 148.
    Beloussov, L. V., Dorfman, J. G., and Cherdantzev, V. G. (1975), Mechanical stresses and morphological patterns in amphibian embryos.J. Embryol. Exp. Morph. 34, 559–574.PubMedGoogle Scholar
  149. 149.
    Hay, E. D. (1982), Collagen and embryonic development. Hay, E. D., ed.Cell Biology of Extracellular Matrix. Plenum, New York, 379–409.Google Scholar
  150. 150.
    Lee, G., Hynes, R., and Kirschner, M. (1984), Temporal and spatial regulation of fibronectin in earlyXenopus development.Cell 36, 729–740.PubMedCrossRefGoogle Scholar
  151. 151.
    Martins-Green, M., and Erickson, C. A. (1986), Development of neural tube basal lamina during neurulation and neural crest cell emigration in the trunk of the mouse embryo.J. Embryol. Exp. Morph. 98, 219–236.PubMedGoogle Scholar
  152. 152.
    Lewis, W. H. (1947), Mechanics of invagination.Anat. Rec. 97, 139–156.CrossRefPubMedGoogle Scholar
  153. 153.
    Honda, H., Yamanaka, H., and Eguchi, G. (1986), Transformation of a polygonal cellular pattern during sexual maturation of the avian oviduct epithelium: computer simulation.J. Embryol. Exp. Morph. 98, 1–19.PubMedGoogle Scholar
  154. 154.
    Flügge, W. (1967),Stresses in Shells, Springer-Verlag, New York.Google Scholar
  155. 155.
    Löfberg, J. (1974), Apical surface topography of invaginating and noninvaginating cells. A scanning-transmission study of amphibian neurulae.Dev. Biol. 36, 311–329.PubMedCrossRefGoogle Scholar
  156. 156.
    Elsdale, T., and Davidson, D. (1987), Timekeeping by frog embryos, in normal development and after heat shock.Development 99(1), 41–49.PubMedGoogle Scholar
  157. 157.
    Gilchrist, F. G. (1968),A Survey of Embryology. McGraw-Hill, New York.Google Scholar
  158. 158.
    Enslee, E. C., and Riddiford, L. M. (1981), Blastokinesis in embryos of the bug,Pyrrhocoris apterus. A light and electron microscopic study 1. Normal blastokinesis.J. Embryol. Exp. Morph. 61, 35–49.PubMedGoogle Scholar
  159. 159.
    Pollard, T. D., Selden, C. S., and Maupin, P. (1984), Interaction of actin filaments with microtubules.J. Cell Biol. 99 (1 Pt. 2), 33–37s.CrossRefGoogle Scholar
  160. 160.
    Holtfreter, J., and Hamburger, V. (1955), Embryogenesis: progressive differentiation, amphibians. Willier, B. H., Weiss, P. A., and Hamburger, V., eds.Analysis of Development. Hafner, New York, 230–296.Google Scholar
  161. 161.
    Gordon, R., Goel, N. S., Steinberg, M. S., and Wiseman, L. L. (1972) A rheological mechanism sufficient to explain the kinetics of cell sorting.J. Theor. Biol. 37, 43–73.PubMedCrossRefGoogle Scholar
  162. 162.
    Gordon, R., Goel, N. S., Steinberg, M. S., and Wiseman, L. L. (1975), A rheological mechanism sufficient to explain the kinetics of cell sorting. Mostow, G. D., ed.Mathematical Models for Cell Rearrangement. Yale University Press, New Haven, 196–230.Google Scholar
  163. 163.
    Rayleigh, L. (1892), On the instability of a cylinder of viscous liquid under capillary force.Phil. Mag. 34, 145–154.Google Scholar
  164. 164.
    Gordon, R., Drum, R. W., Whitmore, E. L., and Aguda, B. D. (1987), The chemical basis for diatom morphogenesis: I. Instabilities in diffusion-limited amorphous precipitation generate space filling branching patterns.J. Theor. Biol. submitted.Google Scholar
  165. 165.
    Volterra, E., and Gaines, J. H. (1971),Advanced Strength of Materials. Prentice-Hall, Englewood Cliffs, NJ.Google Scholar
  166. 166.
    Warner, A., and Gurdon, J. B. (1987), Functional gap junctions are not required for muscle gene activation by induction inXenopus embryos.J. Cell Biol. 104, 557–564.PubMedCrossRefGoogle Scholar
  167. 167.
    Dictus, W. J. A. G., van Zoelen, E. J. J., Tetteroo, P. A. T., Tertoolen, L. G. J., deLaat, S. W., and Bluemink, J. G. (1984), Lateral mobility of plasma membrane lipids inXenopus eggs: regional differences related to animal/vegetal polarity become extreme upon fertilization.Dev. Biol. 101, 201–211.PubMedCrossRefGoogle Scholar
  168. 168.
    Aguda, B., and Gordon, R. (1987), The chemical basis for diatom morphogenesis. II. Mechanochemical feedback controlling precipitation of diatom shells, in preparation.Google Scholar
  169. 169.
    Spemann, H. (1918), Über die Determination der ersten Organanlagen des Amphibienembryo. I–VI.Roux’ Arch. Entw.-Mech.,43, 448–555.Google Scholar
  170. 170.
    Mangold, O. (1929), Experimente zur Analyse der Determination und Induktion der Medullarplatte.Roux’ Arch. Entw.-Mech. 47, 249–301.Google Scholar
  171. 171.
    Lehmann, F. E. (1928), Die Bedeutung der Unterlagerung für die Entwicklung der Medullarplatte vonTriton.Roux’ Arch. Entw.-Mech.,113, 123–171.CrossRefGoogle Scholar
  172. 172.
    Lehmann, F. E. (1929), Die Entwicklung des Anlagenmusters im Ektoderm der Tritongastrula.Roux’ Arch. Entw.-Mech. 117, 312–383.CrossRefGoogle Scholar
  173. 173.
    Machemer, H. (1932), Experimentelle Untersuchungen über die Induktionsleistungen der oberen Urmundlippe in älteren Urodelenkeimen.Roux’ Arch. Entw.-Mech. 126, 391–456.CrossRefGoogle Scholar
  174. 174.
    Schechtman, A. M. (1938), Competence for neural plate formation inHyla regilla and the so-called nervous layer of the ectoderm.Proc. Soc. Exp. Biol. Med. 38, 430–433.Google Scholar
  175. 175.
    Raunich, L. (1942), Induzioni da organizzatori anormali in embrioni di diversa età diTriton taeniatus e Bufo viridid.Monitore Zool. Ital. 53, 227–235.Google Scholar
  176. 176.
    Mangold, O. (1926), Über formative Reize in der Entwicklung der Amphibien.Naturwiss. 14, 1169–1175.CrossRefGoogle Scholar
  177. 177.
    Trinkaus, J. P. (1984),Cells into Organs: The Forces That Shape the Embryo. 2nd ed. Prentice-Hall, Englewood Cliffs, NJ.Google Scholar
  178. 178.
    Culp, L. A. (1978), Biochemical determinants of cell adhesion.Curr. Topics Membrane Transport 11, 327–396.Google Scholar
  179. 179.
    Stanisstreet, M. (1982), Calcium and wound healing inXenopus embryos.J. Embryol. Exp. Morph. 67, 195–205.PubMedGoogle Scholar
  180. 180.
    Bluemink, J. G. (1972), Cortical wound healing in the amphibian egg: an electron microscope study.J. Ultrastruct. Res. 41, 95–114.PubMedCrossRefGoogle Scholar
  181. 181.
    Holtfreter, J. (1944), Neural differentiation of ectoderm through exposure to saline solution.J. Exp. Zool. 95, 307–340.CrossRefGoogle Scholar
  182. 182.
    Davis, L. A., and Lemanski, L. F. (1987), Induction of myofibrillogenesis in cardiac lethal mutant axolotl hearts rescued by RNA derived from normal endoderm.Development 99 (2), 145–154.PubMedGoogle Scholar
  183. 183.
    Brachet, J. (1974),Introduction to Molecular Embryology. English Universities Press, London.Google Scholar
  184. 184.
    Lillie, F. R. (1927), The gene and the ontogenetic process.Science 66, 361–368.PubMedCrossRefGoogle Scholar
  185. 185.
    Slack, J. M. W. (1983),From Egg to Embryo: Determinative Events in Early Development, Cambridge University Press, Cambridge.Google Scholar
  186. 186.
    Ben-Ze’ev, A. (1985), Cell-cell interaction and cell configuration related control of cytokeratins and vimentin expression in epithelial cells and in fibroblasts.Ann. NY Acad. Sci. 455, 597–613.PubMedCrossRefGoogle Scholar
  187. 187.
    Folkman, J., and Moscona, A. (1978), Role of cell shape in growth control.Nature 273, 345–349.PubMedCrossRefGoogle Scholar
  188. 188.
    Afzelius, B. A. (1986), Disorders of ciliary motility.Hospital Practice 21(3), 73–80.PubMedGoogle Scholar
  189. 189.
    Pickett-Heaps, J. D., Tippit, D. H., and Andreozzi, J. A. (1979), Cell division in the pennate diatomPinnularia. III—The valve and associated cytoplasmic organelles.Biol. Cellulaire 35, 195–198.Google Scholar
  190. 190.
    Pickett-Heaps, J. D., Tippit, D. H., and Andreozzi, J. A. (1979), Cell division in the pennate diatomPinnularia. IV—Valve morphogenesis.Biol. Cellulaire 35, 199–203.Google Scholar
  191. 191.
    Pickett-Heaps, J. D. (1983), Valve morphogenesis and the microtubule center in three species of the diatom.Nitzschia J. Physcol. 19, 269–281.Google Scholar
  192. 192.
    Rubino, S., Small, J. V., Claviez, M., Sellitto, C., and Cappuccinelli, P. (1985), Actin filament meshworks and microtubules inDictyostelium discoideum. Alia, E. E., Arena, N., and Russo, M. A., eds.Contractile Proteins in Muscle and Non-Muscle Cell Systems: Biochemistry, Physiology, and Pathology. Praeger Scientific, New York, 51–59.Google Scholar
  193. 193.
    Rappaport, L., Samuel, J. L., Bertier, B., Marotte, F., and Schwartz, K. (1985), Microtubules and growth of myocytes in rat heart. Alia, E. E., Arena, N., and Russo, M. A., eds.Contractile Proteins in Muscle and Non-Muscle Cell Systems: Biochemistry, Physiology, and Pathology. Praeger Scientific, New York, 253–260.Google Scholar
  194. 194.
    Clayton, R. M. (1982), The molecular basis for competence, determination and transdifferentiation: a hypothesis. Clayton, R. M., and Truman, D. E. S., eds.Stability and Switching in Cellular Differentiation. Plenum, New York, 23–38.Google Scholar
  195. 195.
    Bissell, M. J., Hall, G. H., and Parry, G. (1982), How does the extracellular matrix direct gene expression?.J. Theor. Biol. 39, 31–68.CrossRefGoogle Scholar
  196. 196.
    García-Bellido, A. (1975), Genetic control of wing disk development inDrosophila.Ciba Found. Symp. 29, 161–182.PubMedGoogle Scholar
  197. 197.
    Crick, F. H. C., and Lawrence, P. A. (1975), Compartments and polyclones in insect development.Science 189, 340–347.PubMedCrossRefGoogle Scholar
  198. 198.
    Morata, G., and Lawrence, P. A. (1978), Cell lineage and homeotic mutants in the development of imaginal discs ofDrosophila. Subtelny, S., and Sussex, I. M., eds.The Clonal Basis of Development. Academic, New York, 45–60.Google Scholar
  199. 199.
    Lawrence, P. A., and Morata, G. (1979), Pattern formation and compartments in the tarsus ofDrosophila. Subtelny, S., and Konigsberg, I. R., eds.Determinats of Spatial Organization. Academic, New York, 317–323.Google Scholar
  200. 200.
    Wolpert, L. (1969), Positional information and the spatial pattern of cellular differentiation.J. Theor. Biol. 25, 1–47.PubMedCrossRefGoogle Scholar
  201. 201.
    Waddington, C. H. (1940),Organizers and Genes, Cambridge University Press, Cambridge, England.Google Scholar
  202. 202.
    Waddington, C. H. (1956),Principles of Embryology, George Allen and Unwin, London.Google Scholar
  203. 203.
    Sinnott, E. W. (1960),Plant Morphogenesis. McGraw-Hill, New York.Google Scholar
  204. 204.
    Landström, U. (1977), On the differentiation of prospective ectoderm to a ciliated pattern in embryos ofAmbystoma mexicanum.J. Embryol. Exp. Morph. 41, 23–32.PubMedGoogle Scholar
  205. 205.
    Snow, M. H. L. (1986), New data from mammalian homoeobox-containing genes.Nature 324, 618–619.PubMedCrossRefGoogle Scholar
  206. 206.
    Schofield, P. N. (1987), Patterns, puzzles and paradigms; the riddle of the homeobox.Trends Neurosci. 10(1), 3–6.CrossRefGoogle Scholar
  207. 207.
    Honda, H., and Eguchi, G. (1980), How much does the cell boundary contract in a monolayered cell sheet?.J. Theor. Biol. 84, 575–588.PubMedCrossRefGoogle Scholar
  208. 208.
    Owaribe, K., and Masuda, H. (1982), Isolation and characterization of circumferential microfilament bundles from retinal pigmented epithelial cells.J. Cell Biol. 95, 310–315.PubMedCrossRefGoogle Scholar
  209. 209.
    Honda, H. (1983), Geometrical models for cells in tissues.Int. Rev. Cytol. 81, 191–243.PubMedGoogle Scholar
  210. 210.
    Vakaet, L., and Vanroelen, C. (1982), Localization of microfilament bundles in the upper layer of the primitive-streak-stage chick blastoderm.J. Embryol. Exp. Morph. 67, 59–79.Google Scholar
  211. 211.
    Lee, H.-C., and Auersperg, N. (1980), Calcium in epithelial cell contraction.J. Cell Biol. 85(2), 325–336.PubMedCrossRefGoogle Scholar
  212. 212.
    Fluck, R. A., Killian, C. E., Miller, K., Dalpe, J. N., and Shih, T.-M. (1984), Contraction of an embryonic epithelium, the enveloping layer of the medaka (Oryzias latipes), a teleost.J. Exp. Zool. 229, 127–142.CrossRefGoogle Scholar
  213. 213.
    Burgess, D. R. (1982), Reactivation of intestinal epithelial cell brush border motility: ATP-dependent contraction via a terminal web contractile ring.J. Cell Biol. 95, 853–863.PubMedCrossRefGoogle Scholar
  214. 214.
    Balak, K., Jacobson, M., Sunshine, J., and Rutishauser, U. (1987), Neural cell adhesion molecule expression inXenopus embryos.Dev. Biol. 119(2), 540–550.PubMedCrossRefGoogle Scholar
  215. 215.
    Hutchins, R., and Brandhorst, B. P. (1979), Commitment to vegetalized development in sea urchin embryos: failure to detect changes in patterns of protein synthesis.Dev. Biol. 186(2), 95–102.Google Scholar
  216. 216.
    Mayr, E. (1982),The Growth of Biological Thought: Diversity, Evolution, and Inheritance. Harvard University Press, Cambridge, MA.Google Scholar
  217. 217.
    His, W. (1888), On the principles of animal morphology.Roy. Soc. Edinburgh Proc. 15, 287–298.Google Scholar
  218. 218.
    Edelman, G. M. (1985), Cell adhesion molecule expression and the regulation of morphogenesis.Cold Spring Harbor Symp. Quant. Biol. 50, 877–889.PubMedGoogle Scholar
  219. 219.
    Maruyama, M. (1968), Mutual causality in general systems, Milsum, J. H., ed.Positive Feedback, A General Systems Approach to Positive/Negative Feedback and Mutual Causality. Pergamon, Oxford, 80–100.Google Scholar
  220. 220.
    Korn, G. A., and Korn, T. M. (1972),Electronic Analog and Hybrid Computers. 2nd ed. McGraw-Hill, New York.Google Scholar
  221. 221.
    Ben-Ze’ev, A. (1984), Cell-cell interaction and cell-shape-related control of intermediate filament protein synthesis. Borisy, G. G., Cleveland, D. W., and Murphy, D. B., eds.Molecular Biology of the Cytoskeleton. Cold Spring Harbor Laboratory, New York, 435–444.Google Scholar
  222. 222.
    Roux, W. (1888/1964), Contributions to the developmental mechanics of the embryo. On the artificial production of half-embryos by destruction of one of the first two blastomeres, and later development (postgeneration) of the missing half of the body. Willier, B. H., and Oppenheimer, J. M., translators.Foundations of Experimental Embryology. Prentice-Hall, Englewood Cliffs, NJ, 2–37.Google Scholar
  223. 223.
    Fineman, R. M., Schoenwolf, G. C., Huff, M., and Davis, P. L. (1986), Animal model: causes of windowing-induced dysmorphogenesis (neural tube defects and early amnion deficit spectrum) in chicken embryos.Amer. J. Med. Genetics 25, 489–505.CrossRefGoogle Scholar
  224. 224.
    Priess, J. R., and Hirsh, D. I. (1986),Caenorhabditis elegans morphogenesis: the role of the cytoskeleton in elongation of the embryo.Dev. Biol. 117, 156–173.PubMedCrossRefGoogle Scholar
  225. 225.
    Duellman, W. E., and Trueb, L. (1986),Biology of Amphibians. McGraw-Hill, New York.Google Scholar
  226. 226.
    Keller, R. E., Danilchik, M., Gimlich, R., and Shih, J. (1985), The function and mechanism of convergent extension during gastrulation ofXenopus laevis.J. Embryol. Exp. Morph. 89 (Suppl.), 185–209.PubMedGoogle Scholar
  227. 227.
    Jacobson, A. G., Oster, G. F., Odell, G. M., and Cheng, L. Y. (1986), Neurulation and the cortical tractor model for epithelial folding.J. Embryol. Exp. Morph. 96, 19–49.PubMedGoogle Scholar
  228. 228.
    Jacobson, A. G. (1986), Adhesion and movement of cells may be coupled to produce neurulation. Edelman, G. M., and Thiery, J.-P., eds.The Cell in Contact, Adhesions and Junctions as Morphogenetic Determinants. Wiley, New York, 49–65.Google Scholar
  229. 229.
    Keller, R. E. (1984), The cellular basis of gastrulation inXenopus laevis: active, postinvolution convergence and extension by mediolateral interdigitation.Am. Zool. 24, 589–603.Google Scholar
  230. 230.
    vonBertalanffy, L. (1933),Modern Theories of Development, An Introduction to Theoretical Biology. Harper. New York.Google Scholar
  231. 231.
    Suzuki, A., Kuwabara, K., and Kuwabara, Y. (1975), Temporal relations between extension of archenteron roof and realization of neural induction during gastrulation of newt embryo.Dev. Growth Differ. 17, 343–353.CrossRefGoogle Scholar
  232. 232.
    Twitty, V. C., and Bodenstein, D. (1948),Triturus torosus. Rugh, R., ed.Experimental Embryology. Burgess, MN, 94.Google Scholar
  233. 233.
    Jacobson, A. G. (1967), Amphibian cell culture, organ culture, and tissue dissociation, Wilt, F. H., and Wessells, N. K., eds.Methods in Developmental Biology. Thomas Crowell, New York, 531–542.Google Scholar
  234. 234.
    Sadler, T. W., Burridge, K., and Yonker, J. (1986), A potential role for spectrin during neurulation.J. Embryol. Exp. Morph. 94, 73–82.PubMedGoogle Scholar
  235. 235.
    Liu, S.-C., Derick, L. H., and Palek, J. (1987), Visualization of the hexagonal lattice in the erythrocyte membrane skeleton.J. Cell Biol. 104, 527–536.PubMedCrossRefGoogle Scholar
  236. 236.
    Tilney, L. G., and Gibbins, J. R. (1969), Microtubules in the formation and development of the primary mesenchyme inArbacia punctulata II. An experimental analysis of their role in development and maintenance of cell shape.J. Cell Biol. 41, 227–250.PubMedCrossRefGoogle Scholar
  237. 237.
    Kim, S., Magendantz, M., Katz, W., and Solomon, F. (1987), Development of a differentiated microtubule structure.J. Cell Biol. 104, 51–59.PubMedCrossRefGoogle Scholar
  238. 238.
    Steinberg, M. S., Shida, H., Giudice, G. J., Shida, M., Patel, N. H., and Blaschuk, O. W. (1986), On the Molecular Organization, Diversity and Functions of Desmosomal Proteins.CIBA Found. Symp. 125, 325.Google Scholar

Copyright information

© Humana Press Inc. 1987

Authors and Affiliations

  • Richard Gordon
    • 1
  • G. Wayne Brodland
    • 2
  1. 1.Department of Botany and RadiologyUniversity of ManitobaWinnipegCanada
  2. 2.Department of Civil EngineeringUniversity of WaterlooWaterlooCanada

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