Summary
Scanning electron microscopy (SEM) indicates that the primary hypoblast forms beneath the area pellucida during the first 8 h of incubation mainly by establishment of contact among cells which move downward out of the epiblast. This movement, polyingression, begins posteriorly and continues antero-laterally during the period of primary hypoblast formation. Polyingression produces many pits and possibly a crescentic fold in the embryo upper surface with corresponding cell clusters and a ridge on the lower surface. Fixationin situ helps prevent formation of artifactual folds and wrinkles facilitating interpretation of the SEM images.
Formation of intercellular adhesions which lead to development of an epithelial primary hypoblast proceeds in a posterior to anterior direction along with polyingression. This epithelialization begins with elaboration of numerous filamentous processes by cells as they arrive from the epiblast, and continues with ongoing input of cells, merging of cells and cell clusters, and cell flattening. We have also shown (Weinberger and Brick 1982) that proliferation of ingressing cells provides additional cells for hypoblast development.
Similar content being viewed by others
References
Bancroft A, Bellairs R (1974) The onset of differentiation in the epiblast of the chick blastoderm (SEM and TEM). Cell Tiss Res 155:399–418
Bellairs R (1963) Differentiation of the yolk sac of the chick studied by electron microscopy. J Embryol Exp Morphol 11:201–255
Bellairs R, Curtis ASG, Sanders EJ (1978) Cell adhesiveness and embryonic differentiation. J Embryol Exp Morphol 46:207–213
Butler E (1935) The developmental capacity of regions of the unincubated chick blastoderm as tested in chorio-allantoic grafts. J Exp Zool 70:357–396
Eyal-Giladi H, Kochav S (1976) From cleavage to primitive streak formation: a complementary normal table and a new look at the first stages of development of the chick. I. General Morphol Dev Biol 49:321–337
Fontaine J, LeDouarin NM (1977) Analysis of endoderm formation in the avian blastoderm by the use of quail-chick chimeras. J Embryol Exp Morphol 41:209–222
Jacobson W (1938) Early development of the avian embryo I endoderm formation. J Morphol 62:415–443
Lesseps RJ (1963) Cell Surface Projections: Their role in the aggregation of embryonic chick cells as revealed by electron microscopy. J Exp Zool 153:171–182
Litke LL (1978) The ventral surface of the early chick embryo: a scanning electron microscope study. J Submicr Cytol 10:(3) 287–298
New DAT (1959) The adhesive properties and expansion of the chick blastoderm. J Embryol Exptl Morphol 7:146–165
Pasteels J (1937) Etudes sur la gastrulation de vertebres meroblastiques III oiseaux. IV Conclusions Generales. Arch Biol 48:381–488
Peter K (1938) Die Entwicklung des Entoderms beim Hühnchen. J Microsk Anat Forsch 43:362–415
Sanders EJ (1980) The effect of fibronectin and substratum—Attached material on the spreading of chick embryo mesoderm cells in vitro. J Cell Sci 44:225–242
Sanders EJ (1973) Intercellular contact in the unincubated chick embryo. Z Zellforsch 141:459–468
Sanders EJ, Bellairs R, Portch PA (1978) In vivo and in vitro studies on the hypoblast and definitive endoblast of avain embryos. J Embryol Exp Morphol 46:187–205
Spratt NT, Haas H (1960) Morphogenetic movements on the lower surface of the unincubated and early chick blastoderm. J Exp Zool 144:139–157
Spratt NT, Haas H (1961) Integrative mechanisms in development of the early chick blastoderm II role of morphogenetic movements and regenerative growth in synthetic and topographically disarranged blastoderms. J Exp Zool 147:57–94
Spratt NT, Haas H (1965) Germ layer formation and the role of the primitive streak in the chick I basic architecture and morphogenetic tissue movements. J Exp Zool 158:9–38
Steinberg MS (1964) The problem of adhesive selectivity in cellular interactions. In: Locke M (ed) Cellular membranes in development. Academic Press, New York
Trelstad RL, Hay E, Revel JP (1967) Cell contact during early embryogenesis in the chick embryo. J Embryol Exp Morphol 10:38–57
Trinkaus JP (1976) On the mechanism of metazoan cell movements. In: Poste G, Nicholson G (eds) The cell surface in animal embryogenesis and development. Elsevier-North Holland, Amsterdam, pp 225–232
Vakaet L (1962) Some new data concrning the formation of the definitive endoblast in the chick embryo. J Embryol Exp Morphol 10:38–56
Vakaet L (1970) Cinephotomicrographic investigations of gastrulation in the chick blastoderm. Arch Biol Paris 81:387–426
Weinberger C, Brick I (1982) Primary hypoblast development in the chick. II. The role of cell division. Wilhelm Roux's Arch 191:127–133
Weiss L (1970) Cell contact phenomena. In Vitro 5:48–78
Weiss L, Subjeck JR (1974) Electrical heterogeneity of the surfaces of ehrlich ascites tumor cells. Ann NY Acad Sci 238:352–361
Zalik SE, Sanders EJ, Tilney C (1972) Studies on the surface of chick blastoderm cells 1 electrophoretic mobility and pH-mobility relationships. J Cell Physiol 79:225–234
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Weinberger, C., Brick, I. Primary hypoblast development in the chick. Wilhelm Roux' Archiv 191, 119–126 (1982). https://doi.org/10.1007/BF00848449
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00848449