Gastrulation pp 213-223 | Cite as

Convergence and Extension during Germband Elongation in Drosophila Embryos

  • Eric Wieschaus
  • Dari Sweeton
  • Michael Costa
Part of the Bodega Marine Laboratory Marine Science Series book series (BMSS)


After the initial infoldings of gastrulation, the ventral region of the Drosophila embryo undergoes a rapid elongation called germband extension. This elongation is produced by intercalation of the more lateral cells as they move toward the ventral midline. In many respects, the process is very similar to the convergent extension which occurs during amphibian gastrulation and to elongation of the archenteron in sea urchins.

Several years ago, Gergen, Coulter and Wieschaus (1986) proposed that the intercalary behavior of cells during germband elongation reflects the adhesive preferences established in individual cells by the anterior-posterior patterning which occurs at the blastoderm stage. This model is formally very similar to the clock model used by French, Bryant, and Bryant (1976) to explain intercalary regeneration in imaginal discs and vertebrate limbs. In that model, positional values within a field are infinitely graded, and cells tolerate only finite differences between themselves and their immediate neighbors. When the discrepancies between adjacent cells are too great, the cells are induced to divide or otherwise fill in the gap. Surgical manipulations and wound healing induce cell proliferation and intercalary regeneration because they juxtapose cells with radically different positional identities.

In our model for germband extension, similarly abrupt juxtapositions of positional values would arise when the graded segmental field is condensed onto the limited number of precursors cells present in each segment at the gastrula stage. In contrast to the clock model, however, inappropriate juxtapositions in the early embryo are not resolved by induced cell proliferation. Instead, cells from the more dorsal regions which by chance have the appropriate intervening positional identities intercalate.

The article below presents a more detailed description of the model for germband extension and describes several tests of the model based on the predicted behavior of cells in embryos with aberrant anterior-posterior and dorsal-ventral patterning.


Imaginal Disc Drosophila Embryo Segmentation Gene Segmental Pattern Segment Polarity Gene 
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. Akam, M. 1987. The molecular basis for metameric pattern in the Drosophila embryo. Development 101:1–22.PubMedGoogle Scholar
  2. Anderson, K.V., G. Jurgens, and C. Nüsslein-Volhard. 1985. Establishment of dorsal-ventral polarity in the Drosophila embryo: Genetic studies on the role of the Toll gene product. Cell 42:779–789.PubMedCrossRefGoogle Scholar
  3. Carroll, S.B. and M.P. Scott. 1986. Zygotically active genes that affect the spatial expression of the Fushi-tarazu segmentation gene during early Drosophila embryogenesis. Cell 45:113–126.PubMedCrossRefGoogle Scholar
  4. Dinardo, S. and P.H. O’Farrell. 1987. Establishment and refinement of segmental pattern in the Drosophila embryo: spatial control of engrailed expression by pair-rule genes. Genes Dev. 1:1212–1225.PubMedCrossRefGoogle Scholar
  5. Edelman, G.M. 1986. Cell adhesion molecules in the regulation of animal form and tissue pattern. Annu. Rev. Cell Biol. 2:81–116.PubMedCrossRefGoogle Scholar
  6. Ettensohn, C.A. 1985. Gastrulation in the sea urchin embryo is accompanied by the rearrangement of invagination epithelial cells. Dev. Biol. 112:385–390.CrossRefGoogle Scholar
  7. Frasch, M. and M. Levine. 1987. Complementary patterns of even-skipped and fushi tarazu expression involve their differential regulation by a common set of segmentation genes in Drosophila. Genes Dev. 1:981–995.PubMedCrossRefGoogle Scholar
  8. French, V., P.J. Bryant, and S.V. Bryant. 1976. Pattern regeneration in epimorphic fields. Science 193:969–981.PubMedCrossRefGoogle Scholar
  9. Foe, V. 1989. Mitotic domains reveal early commitment of cells in Drosophila embryos. Development 107:1–22.PubMedGoogle Scholar
  10. Gergen, J.P., D. Coulter, and E. Wieschaus. 1986. Segmental pattern and blastoderm cell identities. Symp. Soc. Dev. Biol. 43:195–220.Google Scholar
  11. Gergen, J.P. and E. Wieschaus. 1985. The localized requirements for a gene affecting segmentation in Drosophila: Analysis of larvae mosaic for runt. Dev. Biol. 109:321–335.PubMedCrossRefGoogle Scholar
  12. Gergen, J.P. and E. Wieschaus. 1986. Dosage requirements for runt in the segmentation of Drosophila embryos. Cell 45:289–299.PubMedCrossRefGoogle Scholar
  13. Hardin, J. 1988. The role of secondary mesenchyme cells during sea urchin gastrulation studied by laser ablation. Development 103:317–324.PubMedGoogle Scholar
  14. Hardin, J. and L.Y. Cheng. 1986. The mechanisms and mechanics of archenteron elongation during sea urchin gastrulation. Dev. Biol. 115:490–501.CrossRefGoogle Scholar
  15. Hartenstein, V. and J.A. Campos-Ortega. 1985. Fate mapping in wild type Drosophila melanogaster. I. The spatio-temporal pattern of embryonic cell divisions. Wilhelm Roux’s Arch Dev. Biol. 194:181–195.CrossRefGoogle Scholar
  16. Ingham, P.W, N.E. Baker, and A. Martinez-Arias. 1988. Regulation of segment polarity genes in the Drosophila blastoderm by fushi-tarazu and even-skipped. Nature 331:73–75.PubMedCrossRefGoogle Scholar
  17. Keller, R., M.S. Cooper., M. Danilchik, P. Tibbetts, and P. Wilson. 1989. Cell intercalation during notochord development in Xenopus laevis. J. Exp. Zool. 251: 134–154.PubMedCrossRefGoogle Scholar
  18. Keller, R. and P. Tibbetts. 1989. Mediolateral cell intercalation in the dorsal axial mesoderm of Xenopus laevis. Dev. Biol. 131:539–549.PubMedCrossRefGoogle Scholar
  19. Mittenthal, J.E. 1981. The rule of normal neighbors: A hypothesis for morphogenetic pattern regulation. Dev. Biol. 88:15–26.PubMedCrossRefGoogle Scholar
  20. Nüsslein-Volhard, C. 1979. Maternal effect mutations that alter the spatial coordinates of the embryo of Drosophila melanogaster. Symp. Soc. Dev. Biol. 37:185–211.Google Scholar
  21. Nüsslein-Volhard, C, H.G. Frohnhofer, and R. Lehmann. 1987. Determination of anteroposterior polarity in Drosophila. Science 238:1675–1681.PubMedCrossRefGoogle Scholar
  22. Nüsslein-Volhard, C, H. Kluding, and G. Jurgens. 1985. Genes affecting the segmental subdivision of the Drosophila embryo. Cold Spring Harbor Symp. Quant. Biol. 50:145–154.PubMedCrossRefGoogle Scholar
  23. Nüsslein-Volhard, C. and E. Wieschaus. 1980. Mutations affecting segment number and polarity in Drosophila. Nature 287:795–801.PubMedCrossRefGoogle Scholar
  24. O’Farrell, P. and H.M. Scott. 1986. Spatial programming of gene expression in early Drosophila embryogenesis. Annu. Rev. Cell Biol. 2:49–80.PubMedCrossRefGoogle Scholar
  25. Poulson, D.F. 1950. Histogenesis, organogenesis, and differentiation in the embryo of Drosophila melanogaster Meigen. p. 168–274. In: Biology of Drosophila. M. Demerec (Ed.). John Wiley, New York.Google Scholar
  26. Rickoll, W.L. and S.J. Counce. 1980. Morphogenesis in the embryo of Drosophila melanogaster–Germ band extension. Wilhelm Roux’sArch. Dev. Biol. 188:163–177.CrossRefGoogle Scholar
  27. Schüpbach, G.M. and E. Wieschaus. 1986. Maternal-effect mutations altering the anterior-posterior pattern of the Drosophila embryo. Wilhelm Roux’s Arch. Dev. Biol. 195:302–317.CrossRefGoogle Scholar
  28. Steinberg, M.S. and T.J. Poole. 1982. Liquid behavior of embryonic tissues, p. 583–607. In: Cell Behavior. R. Bellairs, A. Curtis, and G. Dunn (Eds). Cambridge University Press, Cambridge.Google Scholar
  29. Takeichi, M. 1988. The cadherins: Cell-cell adhesion molecules controlling animal morphogenesis. Development 102:639–665.PubMedGoogle Scholar
  30. Turner, F.R. and A.P. Mahowald. 1977. Scanning electron microscopy of Drosophila melanogaster embryogenesis II. Gastrulation and segmentation. Dev. Biol. 57:403–416.PubMedCrossRefGoogle Scholar
  31. Wilson, P.A., G. Oster, and R. Keller. 1989. Cell rearrangement and segmentation in Xenopus: direct observation of cultured explants. Development 105:155–166.PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • Eric Wieschaus
    • 1
  • Dari Sweeton
    • 1
  • Michael Costa
    • 1
  1. 1.Molecular Biology DepartmentPrinceton UniversityPrincetonUSA

Personalised recommendations