QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 5 May 2004
doi: 10.1242/dev.01150

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: dev.01150v1 131/11/2641    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Development Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Smallhorn, M. Articles by Saint, R. Search for Related Content PubMed PubMed Citation Articles by Smallhorn, M. Articles by Saint, R. Social Bookmarking                         What's this?

The epithelial-mesenchymal transition of the Drosophila mesoderm requires the Rho GTP exchange factor Pebble

Centre for the Molecular Genetics of Development and Research School of Biological Sciences, The Australian National University, Canberra, ACT, 0200, Australia

^* Author for correspondence (e-mail: robert.saint{at}anu.edu.au)

Accepted 28 February 2004

Drosophila pebble (pbl) encodes a Rho-family GTP exchange factor (GEF) required for cytokinesis. The accumulation of high levels of PBL protein during interphase and the developmentally regulated expression of pbl in mesodermal tissues suggested that the primary cytokinetic mutant phenotype might be masking other roles. Using various muscle differentiation markers, we found that Even skipped (EVE) expression in the dorsal mesoderm is greatly reduced in pbl mutant embryos. EVE expression in the dorsalmost mesodermal cells is induced in response to DPP secreted by the dorsal epidermal cells. Further analysis revealed that this phenotype is likely to be a consequence of an earlier defect. pbl mutant mesodermal cells fail to undergo the normal epithelial-mesenchymal transition (EMT) and dorsal migration that follows ventral furrow formation. This phenotype is not a secondary consequence of failed cytokinesis, as it is rescued by a mutant form of pbl that does not rescue the cytokinetic defect. In wild-type embryos, newly invaginated cells at the lateral edges of the mesoderm extend numerous protrusions. In pbl mutant embryos, however, cells appear more tightly adhered to their neighbours and extend very few protrusions. Consistent with the dependence of the mesoderm EMT and cytokinesis on actin organisation, the GTP exchange function of the PBL RhoGEF is required for both processes. By contrast, the N-terminal BRCT domains of PBL are required only for the cytokinetic function of PBL. These studies reveal that a novel PBL-mediated intracellular signalling pathway operates in mesodermal cells during the transition from an epithelial to migratory mesenchymal morphology during gastrulation.

Key words: Mesoderm, Cell migration, Epithelial-mesenchymal transition, EMT, Drosophila, Pebble, Rho, GTP exchange factor, RhoGEF

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in Development:

Throwing a pebble into early development

Development 2004 131: e1104. [Full Text]  

This article has been cited by other articles:

				A. van Impel, S. Schumacher, M. Draga, H.-M. Herz, J. Grosshans, and H. A. J. Muller Regulation of the Rac GTPase pathway by the multifunctional Rho GEF Pebble is essential for mesoderm migration in the Drosophila gastrula Development, March 1, 2009; 136(5): 813 - 822. [Abstract] [Full Text] [PDF]

				L. Seguin, C. Liot, R. Mzali, R. Harada, A. Siret, A. Nepveu, and J. Bertoglio CUX1 and E2F1 Regulate Coordinated Expression of the Mitotic Complex Genes Ect2, MgcRacGAP, and MKLP1 in S Phase Mol. Cell. Biol., January 15, 2009; 29(2): 570 - 581. [Abstract] [Full Text] [PDF]

				M. J. Murray and R. Saint Photoactivatable GFP resolves Drosophila mesoderm migration behaviour Development, November 15, 2007; 134(22): 3975 - 3983. [Abstract] [Full Text] [PDF]

				M. Zavortink, N. Contreras, T. Addy, A. Bejsovec, and R. Saint Tum/RacGAP50C provides a critical link between anaphase microtubules and the assembly of the contractile ring in Drosophila melanogaster J. Cell Sci., November 15, 2005; 118(22): 5381 - 5392. [Abstract] [Full Text] [PDF]

				C. Linker, C. Lesbros, J. Gros, L. W. Burrus, A. Rawls, and C. Marcelle {beta}-Catenin-dependent Wnt signalling controls the epithelial organisation of somites through the activation of paraxis Development, September 1, 2005; 132(17): 3895 - 3905. [Abstract] [Full Text] [PDF]

				M. Padash Barmchi, S. Rogers, and U. Hacker DRhoGEF2 regulates actin organization and contractility in the Drosophila blastoderm embryo J. Cell Biol., February 14, 2005; 168(4): 575 - 585. [Abstract] [Full Text] [PDF]

				R. Wilson, E. Vogelsang, and M. Leptin FGF signalling and the mechanism of mesoderm spreading in Drosophila embryos Development, February 1, 2005; 132(3): 491 - 501. [Abstract] [Full Text] [PDF]

				Z. Han, X. Li, J. Wu, and E. N. Olson A myocardin-related transcription factor regulates activity of serum response factor in Drosophila PNAS, August 24, 2004; 101(34): 12567 - 12572. [Abstract] [Full Text] [PDF]