Mechanics and Genetics of Cell Shape Changes during Drosophila Ventral Furrow Formation
The folding of epithelia is an important morphogenetic process that turns flat sheets of cells into more complex three-dimensional structures. It occurs at various stages of embryogenesis in the development of many different organs, and during gastrulation. The first morphogenetic movement during Drosophila gastrulation is the invagination of the ventral furrow, which is the beginning of the infolding of the mesoderm. Ventral furrow formation is particularly well suited for the analysis of epithelial folding. First, it is simple and quick; the invaginating cell sheet is a homogeneous, single layer epithelium which changes its shape to form a tube in a period of less than half an hour. Second, no cell division or growth occurs during this process. Finally, many of the genes that determine the fates of the cells in and around the ventral furrow are known. This allows us to define cell populations not only by their behavior, but also by the expression patterns of specific genes. Furthermore, mutations in these genes can be used to change the fates of cells in the embryo in order to test the contributions of different populations to the movements of gastrulation. Eventually, we hope to find out how the genes that determine cell fates regulate the behavior of cells, directing them to undergo the morphogenetic changes of gastrulation. This paper describes the events during ventral furrow formation and shows how we have made use of Drosophila genetics to analyze the forces and mechanisms involved in the invagination of the furrow.
KeywordsGerm Band Cell Shape Change Dorsoventral Axis Ventral Cell Apical Constriction
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- Burnside, B. 1973. Microtubules and microfilaments in amphibian neurulation. Am. Zool. 13:989–1006.Google Scholar
- Campos-Ortega, J.A. and V. Hartenstein. 1985. The Embryonic Development of Drosophila melanogaster. Springer Verlag, Berlin.Google Scholar
- Fullilove, S.L. and A.G. Jacobson. 1978. Embryonic Development: Descriptive, p. 105–227. In: Genetics and Biology of Drosophila, Vol. 2c. M. Ashburner and E. Novitski (Eds.). Academic Press, New York.Google Scholar
- Jacobsen, 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.Google Scholar
- Kam, Z., J.S. Minden, D.A. Agard, J.W. Sedat, and M. Leptin. 1991. Drosophila gastrulation: Analysis of cell behavior in living embryos by three-dimensional fluorescence microscopy. Development112:365–370.Google Scholar