Affiliation:
1. Max-Planck-Institute of Molecular Cell Biology and Genetics,Pfotenhauerstrasse 108, 01307 Dresden, Germany
Abstract
During vertebrate gastrulation, the three germ layers, ectoderm, mesoderm and endoderm are formed, and the resulting progenitor cells are brought into the positions from which they will later contribute more complex tissues and organs. A core element in this process is the internalization of mesodermal and endodermal progenitors at the onset of gastrulation. Although many of the molecules that induce mesendoderm have been identified, much less is known about the cellular mechanisms underlying mesendodermal cell internalization and germ layer formation.Here we show that at the onset of zebrafish gastrulation, mesendodermal progenitors in dorsal/axial regions of the germ ring internalize by single cell delamination. Once internalized, mesendodermal progenitors upregulate E-Cadherin (Cadherin 1) expression, become increasingly motile and eventually migrate along the overlying epiblast (ectodermal) cell layer towards the animal pole of the gastrula. When E-Cadherin function is compromised,mesendodermal progenitors still internalize, but, with gastrulation proceeding, fail to elongate and efficiently migrate along the epiblast,whereas epiblast cells themselves exhibit reduced radial cell intercalation movements. This indicates that cadherin-mediated cell-cell adhesion is needed within the forming shield for both epiblast cell intercalation, and mesendodermal progenitor cell elongation and migration during zebrafish gastrulation.Our data provide insight into the cellular mechanisms underlying mesendodermal progenitor cell internalization and subsequent migration during zebrafish gastrulation, and the role of cadherin-mediated cell-cell adhesion in these processes.
Publisher
The Company of Biologists
Subject
Developmental Biology,Molecular Biology
Reference45 articles.
1. Ataliotis, P., Symes, K., Chou, M. M., Ho, L. and Mercola,M. (1995). PDGF signalling is required for gastrulation of Xenopus laevis. Development121,3099-3110.
2. Babb, S. G. and Marrs, J. A. (2004). E-cadherin regulates cell movements and tissue formation in early zebrafish embryos. Dev. Dyn.230,263-277.
3. Barth, K. A. and Wilson, S. W. (1995). Expression of zebrafish nk2.2 is influenced by sonic hedgehog/vertebrate hedgehog-1 and demarcates a zone of neuronal differentiation in the embryonic forebrain. Development121,1755-1768.
4. Branford, W. W. and Yost, H. J. (2002). Lefty-dependent inhibition of nodal- and wnt-responsive organizer gene expression is essential for normal gastrulation. Curr. Biol.12,2136-2141.
5. Carmany-Rampey, A. and Schier, A. F. (2001). Single-cell internalization during zebrafish gastrulation. Curr. Biol.11,1261-1265.
Cited by
160 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献