Cell Movements in the Epiblast During Gastrulation and Neurulation in Avian Embryos

  • Gary C. Schoenwolf
Part of the Bodega Marine Laboratory Marine Science Series book series (BMSS)


In this essay, I will focus on both gastrulation and neurulation in avian embryos. The two processes are driven by similar cell behaviors: cell shape changes, cell division, and cell rearrangements. Since we have made considerable progress in understanding how these cell behaviors function in avian neurulation, perhaps more so than in gastrulation, I will draw heavily on this material.


Neural Tube Chick Embryo Neural Plate Primitive Streak Avian Embryo 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alvarez, I.S. and G.C. Schoenwolf. 1991. Patterns of neuroepithelial cell rearrangement during avian neurulation are established independently of notochordal inductive interactions. Dev. Biol. 143:78–92.PubMedGoogle Scholar
  2. Bellairs, R. 1964. Biological aspects of the yolk of the hen’s egg. Adv. Morphog. 4:217–272.PubMedGoogle Scholar
  3. Bellairs, R. 1986. The primitive streak. Anat. Embryol. 174:1–14.PubMedGoogle Scholar
  4. Bellairs, R., F.W. Lorenz, and T. Dunlap. 1978. Cleavage in the chick embryo. J. Embryol. Exp. Morphol. 43:55–69.PubMedGoogle Scholar
  5. Burnside, B. 1973. Microtubules and microfilaments in amphibian neurulation. Am. Zool. 13:989–1006.Google Scholar
  6. Callebaut, M. 1974. La formation de l’oocyte d’oiseau. Etude autoradiographique chez la caille japonaise pondeuse à l’aide de la leucine tritiée. Arch. Biol. 85:201–233.Google Scholar
  7. Callebaut, M. 1983. The constituent oocytal layers of the avian germ and the origin of the primordial germ cell yolk. Arch. Anat. Microsc. Morphol. Exp. 72:199–214.PubMedGoogle Scholar
  8. Callebaut, M. 1985. Link between avian oogenesis and gastrulation: demonstration of a cytoplasmic pre-embryonic fate map by trypan blue induced fluorescence. IRCS Med. Sci. 13:711–712.Google Scholar
  9. Canning, D.R. and C.D. Stern. 1988. Changes in the expression of the carbohydrate epitope HKN-1 associated with mesoderm induction in the chick embryo. Development 104:643–655.PubMedGoogle Scholar
  10. Chan, W.Y. and P.P.L. Tarn. 1988. A morphological and experimental study of the mesencephalic neural crest cells in the mouse embryo using wheat germ agglutinin-gold conjugate as the cell marker. Development 102:427–442.PubMedGoogle Scholar
  11. Costanzo, R., R.L. Watterson, and G.C. Schoenwolf. 1982. Evidence that secondary neurulation occurs autonomously in the chick embryo. J. Exp. Zool. 219:233–240.PubMedGoogle Scholar
  12. Criley, B.B. 1969. Analysis of the embryonic sources and mechanisms of development of posterior levels of chick neural tubes. J. Morphol. 128:465–501.PubMedGoogle Scholar
  13. Dias, M.S. and G.C. Schoenwolf. 1990. Formation of ectopic neurepithelium in chick blastoderms: Age-related capacities for induction and self-differentiation following transplantation of quail Hensen’s nodes. Anat. Rec. 229:437–448.Google Scholar
  14. Dodd, J. and T.M. Jessell. 1988. Axon guidance and the patterning of neuronal projections in vertebrates. Science 242:692–699.PubMedGoogle Scholar
  15. Dryden, R. J. 1980. Spina bifida in chick embryos: Ultrastructure of open neural defects in the transitional region between primary and secondary modes of neural tube formation, p. 75–100. In: Advances in the Study of Birth Defects. T.V.N. Persaud (Ed.). MTP Press Ltd., Lancaster.Google Scholar
  16. Erickson, C.A. and J.A. Weston. 1983. An SEM analysis of neural crest migration in the mouse. J. Embryol Exp. Morphol. 74:97–118.PubMedGoogle Scholar
  17. Eyal-Giladi, H. and S. Kochav. 1976. From cleavage to primitive streak formation: A complementary normal table and a new look at the first stages of the development of the chick. I. General morphology. Dev. Biol. 49:321–337.PubMedGoogle Scholar
  18. Fraser, S., R. Keynes, and A. Lumsden. 1990. Segmentation in the chick embryo hindbrain is defined by cell lineage restrictions. Nature 344:431–435.PubMedGoogle Scholar
  19. Gallera, J. 1971. Primary induction in birds. Adv. Morphog. 9:149–180.PubMedGoogle Scholar
  20. 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. Morphol. Suppl. 89:229–255.Google Scholar
  21. Griffith, C.M. and M.J. Wiley. 1990. Distribution of cell surface glycoconjugates during chick secondary neurulation. Anat. Rec. 226:81–90.PubMedGoogle Scholar
  22. Gurdon, J.B. 1987. Embryonic induction—molecular prospects. Development 99:285–306.PubMedGoogle Scholar
  23. Hamburger, V. and H.L. Hamilton. 1951. A series of normal stages in the development of the chick embryo. J. Morphol. 88:49–92.Google Scholar
  24. Harrisson, F. 1989. The extracellular matrix and cell surface, mediators of cell interactions in chicken gastrulation. Int. J. Dev. Biol. 33:417–438.PubMedGoogle Scholar
  25. Holmdahl, D.E. 1925a. Die erste Entwicklung des Körpers bei den Vögeln und Säugetieren, inkl. dem Menschen, besonders mit Rücksicht auf die Bildung des Rückenmarks, des Zöloms und der entodermalen Kloake nebst einem Exkurs über die Entstehung der Spina bifida in der Lumbosakralregion. Gegenbaurs Morphol. Jahrb. I. 54:333–384.Google Scholar
  26. Holmdahl, D.E. 1925b. Experimentelle Untersuchungen über die Lage der Grenze zwischen primarer und sekundarer Körperentwicklung beim Huhn. Anat. Anz. 59:393–396.Google Scholar
  27. Jacobson, A.G. 1980. Computer modeling of morphogenesis. Am. Zool. 20:669–677.Google Scholar
  28. Jacobson, A.G. 1981. Morphogenesis of the neural plate and tube. p. 233–263. In: Morphogenesis and Pattern Formation. T.G. Connelly, L.L. Brinkley, and B.M. Carlson (Eds.). Raven Press, New York.Google Scholar
  29. Jacobson, A.G., G.F. Oster, G.M. Odell, and L.Y. Cheng. 1986. Neurulation and the cortical tractor model for epithelial folding. J. Embryol. Exp. Morphol. 96:19–49.PubMedGoogle Scholar
  30. Jacobson, C.-O. and T. Ebendal (Eds.). 1978. Formshaping Movements in Neurogenesis.Almqvist & Wiksell International, Stockholm.Google Scholar
  31. Jaffe, L.F. and C.D. Stern. 1979. Strong electrical currents leave the primitive streak region of chick embryos. Science 206:569–571.PubMedGoogle Scholar
  32. Jessell, T.M., P. Bovolenta, M. Placzek, M. Tessier-Lavigne, and J. Dodd. 1989. Polarity and patterning in the neural tube: the origin and function of the floor plate, p. 257–282. In: Cellular Basis of Morphogenesis, Ciba Foundation Symposium. Wiley, Chichester.Google Scholar
  33. Karfunkel, P. 1974. The mechanisms of neural tube formation. Int. Rev. Cytol. 38:245–271.PubMedGoogle Scholar
  34. Keller, R.E. 1975. Vital dye mapping of the gastrula and neurula of Xenopus laevis. I. Prospective areas and morphogenetic movements of the superficial layer. Dev. Biol. 42:222–241.PubMedGoogle Scholar
  35. Keller, R.E. 1978. Time-lapse cinemicrographic analysis of superficial cell behavior during and prior to gastrulation in Xenopus laevis. J. Morphol. 157:223–247.Google Scholar
  36. Keller, R.E. 1980. The cellular basis of epiboly: An SEM study of deep cell rearrangement during gastrulation in Xenopus laevis. J. Embryol. Exp. Morphol. 60:201–234.PubMedGoogle Scholar
  37. Kochav, S. and H. Eyal-Giladi. 1971. Bilateral symmetry in chick embryo determination by gravity. Science 171:1027–1029.PubMedGoogle Scholar
  38. Kochav, S., M. Ginsburg, and H. Eyal-Giladi. 1980. From cleavage to primitive streak formation: A complementary normal table and a new look at the first stages of the development of the chick. II. Microscopic anatomy and cell population dynamics. Dev. Biol. 79:296–308.PubMedGoogle Scholar
  39. Langman, J., R.L. Guerrant, and B.G. Freeman. 1966. Behavior of neuro-epithelial cells during closure of the neural tube. J. Comp. Neurol. 127:399–412.PubMedGoogle Scholar
  40. LeDouarin, N.M. 1973. A Feulgen-positive nucleolus. Exp. Cell Res. 77:459–468.Google Scholar
  41. LeDouarin, N.M. 1982. The Neural Crest. Cambridge University Press, London.Google Scholar
  42. Lee, H.-Y., R.G. Nagele, and G.W. Kalmus. 1976a. Further studies on neural tube defects caused by Concanavalin A in early chick embryos. Experientia 32:1050–1052.PubMedGoogle Scholar
  43. Lee, H.-Y., J.B. Sheffield, R.G. Nagele, and G.W. Kalmus. 1976b. The role of extracellular material in chick neurulation. I. Effects of Concanavalin A. J. Exp. Zool. 198:261–266.PubMedGoogle Scholar
  44. Mak, L.L. 1978. Ultrastructural studies of amphibian neural fold fusion. Dev. Biol. 65:435–446.PubMedGoogle Scholar
  45. Martin, A. and J. Langman. 1965. The development of the spinal cord examined by autoradiography. J. Embryol Exp. Morphol. 14:25–35.PubMedGoogle Scholar
  46. Martins-Green, M. 1988. Origin of the dorsal surface of the neural tube by progressive delamination of epidermal ectoderm and neuroepithelium: Implications for neurulation and neural tube defects. Development 103:687–706.PubMedGoogle Scholar
  47. Moran, D. and R.W. Rice. 1975. An ultrastructural examination of the role of cell membrane surface coat material during neurulation. J. Cell Biol. 64:172–181.PubMedGoogle Scholar
  48. Nalbandov, A.V. and M.F. James. 1949. The blood-vascular system of the chicken ovary. Am. J. Anat. 85:347–378.PubMedGoogle Scholar
  49. New, D.A.T. 1956. The formation of sub-blastodermic fluid in hens’ eggs. J. Embryol. Exp. Morphol. 4:221–227.Google Scholar
  50. Nichols, D.H. 1981. Neural crest formation in the head of the mouse embryo as observed using a new histological technique. J. Embryol. Exp. Morphol. 64:105–120.PubMedGoogle Scholar
  51. Nicolet, G. 1970. Analyse autoradiographique de la localisation des différentes ébauches présomptives dans la ligne primitive de l’embryon de Poulet. J. Embryol. Exp. Morphol. 23:79–108.Google Scholar
  52. Nicolet, G. 1971. Avian gastrulation. Adv. Morphog. 9:231–262.PubMedGoogle Scholar
  53. Ooi, V.E.C., E.J. Sanders, and R. Bellairs. 1986. The contribution of the primitive streak to the somites in the avian embryo. J. Embryol. Exp. Morphol. 92:193–206.PubMedGoogle Scholar
  54. O’Shea, S. 1981. The cytoskeleton in neurulation: Role of cations, p. 35–60. In: Progress in Anatomy. R.J. Harrison (Ed.). Cambridge University Press, London.Google Scholar
  55. Penner, P.L. and I. Brick. 1984. Acetylcholinesterase and polyingression in the epiblast of the primitive streak chick embryo. Wilhelm Roux’s Arch. Dev. Biol. 193:234–241.Google Scholar
  56. Placzek, M., M. Tessier-Lavigne, T. Yamada, T. Jessell, and J. Dodd. 1991. Mesodermal control of neural cell identity: Floor plate induction by the notochord. Science 250:985–988.Google Scholar
  57. Rice, R.W. and D.J. Moran. 1977. A scanning electron microscope and X-ray microanalytic study of cell surface material during amphibian neurulation. J. Exp. Zool. 201:471–478.PubMedGoogle Scholar
  58. Rosenquist, G.C. 1966. A radioautographic study of labeled grafts in the chick blastoderm. Development from primitive-streak stages to stage 12. Carnegie Inst. Wash. Contrib. Embryol. 38:31–110.Google Scholar
  59. Sadler, T.W. 1978. Distribution of surface coat material on fusing neural folds of mouse embryos during neurulation. Anat. Rec. 191:345–350.PubMedGoogle Scholar
  60. Sanders, E.J., M.K. Khare, V.C. Ooi, and R. Bellairs. 1986. An experimental and morphological analysis of the tail bud mesenchyme of the chick embryo. Anat. Embryol. 174:179–185.PubMedGoogle Scholar
  61. Schoenwolf, G.C. 1977. Tail (end) bud contributions to the posterior region of the chick embryo. J. Exp. Zool. 201:227–246.Google Scholar
  62. Schoenwolf, G.C. 1978a. Effects of complete tail bud extirpation on early development of the posterior region of the chick embryo. Anat. Rec. 192:289–296.PubMedGoogle Scholar
  63. Schoenwolf, G.C. 1978b. An SEM study of posterior spinal cord development in the chick embryo. Scanning Electron Microsc. 1978/II:739–746.Google Scholar
  64. Schoenwolf, G.C. 1979a. Histological and ultrastructural observations of tail bud formation in the chick embryo. Anat. Rec. 193:131–148.PubMedGoogle Scholar
  65. Schoenwolf, G.C. 1979b. Observations on closure of the neuropores in the chick embryo. Am. J. Anat. 155:445–466.PubMedGoogle Scholar
  66. Schoenwolf, G.C. 1982. On the morphogenesis of the early rudiments of the developing central nervous system. Scanning Electron Microsc. 1982/I:289–308.Google Scholar
  67. Schoenwolf, G.C. 1983. The chick epiblast: A model for examining epithelial morphogenesis. Scanning Electron Microsc. 1983/III:1371–1385.Google Scholar
  68. Schoenwolf, G.C. 1985. Shaping and bending of the avian neuroepithelium: Morphometric analyses. Dev. Biol. 109:127–139.PubMedGoogle Scholar
  69. Schoenwolf, G.C. 1988. Microsurgical analyses of avian neurulation: Separation of medial and lateral tissues. J. Comp. Neurol. 276:498–507.PubMedGoogle Scholar
  70. Schoenwolf, G.C. 1991. Neurepithelial cell behavior during avian neurulation. In: Cell-Cell Interactions in Early Development. J. Gerhart (Ed.). Alan R. Liss, Inc., New York. In press.Google Scholar
  71. Schoenwolf, G.C. and I.S. Alvarez. 1989. Roles of neuroepithelial cell rearrangement and division in shaping of the avian neural plate. Development 106:427–439.PubMedGoogle Scholar
  72. Schoenwolf, G.C, H. Bortier, and L. Vakaet. 1989a. Fate mapping the avian neural plate with quail/chick chimeras: Origin of prospective median wedge cells. J. Exp. Zool. 249:271–278.PubMedGoogle Scholar
  73. Schoenwolf, G.C, N.B. Chandler, and J. Smith. 1985. Analysis of the origins and early fates of neural crest cells in caudal regions of avian embryos. Dev. Biol. 110:467–479.PubMedGoogle Scholar
  74. Schoenwolf, G.C. and J. DeLongo. 1980. Ultrastructure of secondary neurulation in the chick embryo. Am. J. Anat. 158:43–63.PubMedGoogle Scholar
  75. Schoenwolf, G.C, S. Everaert, H. Bortier, and L. Vakaet. 1989b. Neural plate- and neural tube-forming potential of isolated epiblast areas in avian embryos. Anat. Embryol. 179:541–549.PubMedGoogle Scholar
  76. Schoenwolf, G.C. and M.V. Franks. 1984. Quantitative analyses of changes in cell shapes during bending of the avian neural plate. Dev. Biol. 105:257–272.PubMedGoogle Scholar
  77. Schoenwolf, G.C. and R.O. Kelley. 1980. Characterization of intercellular junctions in the caudal portion of the developing neural tube of the chick embryo. Am. J. Anat. 158:29–41.PubMedGoogle Scholar
  78. Schoenwolf, G.C. and D.H. Nichols. 1984. Histological and ultrastructural studies on the origin of caudal neural crest cells in mouse embryos. J. Comp. Neurol. 222:496–505.PubMedGoogle Scholar
  79. Schoenwolf, G.C. and M.L. Powers. 1987. Shaping of the chick neuroepithelium during primary and secondary neurulation: Role of cell elongation. Anat. Rec. 218:182–195.PubMedGoogle Scholar
  80. Schoenwolf, G.C. and P. Sheard. 1989. Shaping and bending of the avian neural plate as analysed with a fluorescent-histochemical marker. Development 105:17–25.PubMedGoogle Scholar
  81. Schoenwolf, G.C. and P. Sheard. 1990. Fate mapping the avian epiblast with focal injections of a fluorescent-histochemical marker: Ectodermal derivatives. J. Exp. Zool. 255:323–339.PubMedGoogle Scholar
  82. Schoenwolf, G.C. and J.L. Smith. 1990a. Epithelial cell wedging: A fundamental cell behavior contributing to hinge point formation during epithelial morphogenesis. In: Control of Morphogenesis by Specific Cell Behaviors. R.E. Keller and D. Fristrom (Eds.). W.B. Saunders Co., London. 1:325–334.Google Scholar
  83. Schoenwolf, G.C. and J.L. Smith. 1990b. Mechanisms of neurulation: Traditional viewpoint and recent advances. Development 109:243–270.PubMedGoogle Scholar
  84. Schroeder, T.E. 1970. Neurulation in Xenopus laevis. An analysis and model based upon light and electron microscopy. J. Embryol. Exp. Morphol. 23:427–462.PubMedGoogle Scholar
  85. Silver, M.H. and J.M. Kerns. 1978. Ultrastructure of neural fold fusion in chick embryos. Scanning Electron Microsc. 1978/II:209–215.Google Scholar
  86. Smith, J.L. and G.C. Schoenwolf. 1987. Cell cycle and neuroepithelial cell shape during bending of the chick neural plate. Anat. Rec. 218:196–206.PubMedGoogle Scholar
  87. Smith, J.L. and G.C. Schoenwolf. 1988. Role of cell-cycle in regulating neuroepithelial cell shape during bending of the chick neural plate. Cell Tissue Res. 252:491–500.PubMedGoogle Scholar
  88. Smith, J.L. and G.C. Schoenwolf. 1989. Notochordal induction of cell wedging in the chick neural plate and its role in neural tube formation. J. Exp. Zool. 250:49–62.PubMedGoogle Scholar
  89. Smith, J.L. and G.C. Schoenwolf. 1991. Further evidence of extrinsic forces in bending of the neural plate. J. Comp. Neurol. 307:225–236.PubMedGoogle Scholar
  90. Smits-van Prooije, A.E., R.E. Poelmann, A.F. Gesink, M.J. van Groeningen, and C. Vermeij-Keers. 1986. The cell surface coat in neurulating mouse and rat embryos, studied with lectins. Anat. Embryol. 175:111–117.PubMedGoogle Scholar
  91. Spemann, H. 1938. Embryonic Development and Induction. Yale University Press, New Haven.Google Scholar
  92. Spratt, N.T., Jr. 1942. Location of organ-specific regions and their relationship to the development of the primitive streak in the early chick blastoderm. J. Exp. Zool. 89:69–101.Google Scholar
  93. Spratt, N.T., Jr. 1952. Localization of the prospective neural plate in the early chick blastoderm. J. Exp. Zool. 120:109–130.Google Scholar
  94. Spratt, NT., Jr. 1955. Analysis of the organizer center in the early chick embryo. I. Localization of prospective notochord and somite cells. J. Exp. Zool. 128:121–164.Google Scholar
  95. Spratt, N.T., Jr. 1963. Role of substratum, supracellular continuity, and differential growth in morphogenetic cell movements. Dev. Biol. 7:51–63.PubMedGoogle Scholar
  96. Spratt, N.T., Jr. and H. Haas. 1960a. Importance of morphogenetic movements in the lower surface of the young chick blastoderm. J. Exp. Zool. 144:257–276.Google Scholar
  97. Spratt, N.T., Jr. and H. Haas. 1960b. Morphogenetic movements in the lower surface of the unincubated and early chick blastoderm. J. Exp. Zool. 144:139–157.Google Scholar
  98. Stern, C.D. 1990. The marginal zone and its contribution to the hypoblast and primitive streak of the chick embryo. Development 109:667–682.PubMedGoogle Scholar
  99. Stern, C. 1991. Mesoderm Formation in the Chick Embryo, Revisited, p. 29–42. In: Gastrulation: Movements, Patterns, and Molecules. R. Keller, W.H. Clark Jr., F. Griffin (Eds.). Plenum Press, New York.Google Scholar
  100. Stern, C.D. and D.R. Canning. 1988. Gastrulation in birds: A model system for the study of animal morphogenesis. Experientia 44:651–657.PubMedGoogle Scholar
  101. Stern, C.D. and D.R. Canning. 1990. Origin of cells giving rise to mesoderm and endoderm in chick embryo. Nature 343:273–275.PubMedGoogle Scholar
  102. Stern, C.D. and D.O. MacKenzie. 1983. Sodium transport and the control of epiblast polarity in the early chick embryo. J. Embryol. Exp. Morphol. 77:73–98.PubMedGoogle Scholar
  103. Stern, C.D., S. Manning, and J.I. Gillespie. 1985. Fluid transport across the epiblast of the early chick embryo. J. Embryol. Exp. Morphol. 88:365–384.PubMedGoogle Scholar
  104. Takahashi, H. 1988. Changes in peanut lectin binding sites on the neuroectoderm during neural tube formation in the bantam chick embryo. Anat. Embryol. 178:353–358.PubMedGoogle Scholar
  105. Takahashi, H. and R.I. Howes. 1986. Binding pattern of ferritin-labeled lectins (RCA1 and WGA) during neural tube closure in the bantam embryo. Anat. Embryol. 174:283–288.PubMedGoogle Scholar
  106. Tan, S.S. and G. Morriss-Kay. 1985. The development and distribution of cranial neural crest in the rat embryo. Cell Tissue Res. 240:403–416.PubMedGoogle Scholar
  107. Vakaet, L. 1962. Some new data concerning the formation of the definitive endoblast in the chick embryo. J. Embryol. Exp. Morphol. 10:38–57.PubMedGoogle Scholar
  108. Vakaet, L. 1970. Cinephotomicrographic investigations of gastrulation in the chick blastoderm. Arch. Biol. 81:387–426.Google Scholar
  109. Vakaet, L. 1984. Early development of birds, p. 71–88. In: Chimeras in Developmental Biology. N. LeDouarin and A. McLaren (Eds.). Academic Press, London.Google Scholar
  110. Vakaet, L. 1985. Morphogenetic movements and fate maps in the avian blastoderm, p. 99–109. In: Molecular Determinants of Animal Form. G.M. Edelman (Ed.). Alan R. Liss, New York.Google Scholar
  111. van Straaten, H.W.M., J.W.M. Hekking, E.J.L.M. Wiertz-Hoessels, F. Thors, and J. Drukker. 1988. Effect of the notochord on the differentiation of a floor plate area in the neural tube of the chick embryo. Anat. Embryol. 177:317–324.PubMedGoogle Scholar
  112. Veini, M. and K. Hara. 1975. Changes in the differentiation tendencies of the hypoblast-free Hensen’s node during “gastrulation” in the chick embryo. Wilhelm Roux’ Arch. Entwicklungsmech. Org. 177:89–100.Google Scholar
  113. Waterman, R.E. 1975. SEM observations of surface alterations associated with neural tube closure in the mouse and hamster. Anat. Rec. 183:95–98.PubMedGoogle Scholar
  114. Waterman, R.E. 1976. Topographical changes along the neural fold associated with neurulation in the hamster and mouse. Am. J. Anat. 146:151–172.PubMedGoogle Scholar
  115. Weinberger, C. and I. Brick. 1982a. Primary hypoblast development in the chick. I. Scanning electron microscopy of normal development. Wilhelm Roux’s Arch. Dev. Biol. 191:119–126.Google Scholar
  116. Weinberger, C. and I. Brick. 1982b. Primary hypoblast development in the chick. II. The role of cell division. Wilhelm Roux’s Arch. Dev. Biol. 191:127–133.Google Scholar
  117. Weinberger, C, P.L. Penner, and I. Brick. 1984. Polyingression, an important morphogenetic movement in chick gastrulation. Am. Zool. 24:545–554.Google Scholar

Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • Gary C. Schoenwolf
    • 1
  1. 1.Department of Anatomy School of MedicineUniversity of UtahSalt Lake CityUSA

Personalised recommendations