|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 23 November 2004
doi: 10.1242/jcs.01552
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ontario, M5S 3G5, Canada
* Author for correspondence (e-mail: utepass{at}zoo.utoronto.ca)
Accepted 21 September 2004
Hemocyte development in the Drosophila embryo is a genetic model to study blood cell differentiation, cell migration and phagocytosis. Macrophages, which make up the majority of embryonic hemocytes, migrate extensively as individual cells on basement membrane-covered surfaces. The molecular mechanisms that contribute to this migration process are currently not well understood. We report the generation, by P element replacement, of two Gal4 lines that drive expression of UAS-controlled target genes during early (gcm-Gal4) or late (Coll-Gal4) stages of macrophage migration. gcm-Gal4 is used for live imaging analysis showing that macrophages extend large, dynamic lamellipodia as their main protrusions as well as filopodia. We use both Gal4 lines to express dominantnegative and constitutively active isoforms of the Rho GTPases Rac1, Cdc42, Rho1 and RhoL in macrophages, and complement these experiments by analyzing embryos mutant for Rho GTPases. Our findings suggest that Rac1 and Rac2 act redundantly in controlling migration and lamellipodia formation in Drosophila macrophages, and that the third Drosophila Rac gene, Mtl, makes no significant contribution to macrophage migration. Cdc42 appears not to be required within macrophages but in other tissues of the embryo to guide macrophages to the ventral trunk region. No evidence was found for a requirement of Rho1 or RhoL in macrophage migration. Finally, to estimate the number of genes whose zygotic expression is required for macrophage migration we analyzed 208 chromosomal deletions that cover most of the Drosophila genome. We find eight deletions that cause defects in macrophage migration suggesting the existence of approximately ten zygotic genes essential for macrophage migration.
Key words: Cell migration, UAS-Gal4 system, Rho GTPases, Hemocyte, Cytokinesis, Macrophage
This article has been cited by other articles:
![]() |
D. T. Babcock, A. R. Brock, G. S. Fish, Y. Wang, L. Perrin, M. A. Krasnow, and M. J. Galko Circulating blood cells function as a surveillance system for damaged tissue in Drosophila larvae PNAS, July 22, 2008; 105(29): 10017 - 10022. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Martinek, J. Shahab, M. Saathoff, and M. Ringuette Haemocyte-derived SPARC is required for collagen-IV-dependent stability of basal laminae in Drosophila embryos J. Cell Sci., May 15, 2008; 121(10): 1671 - 1680. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Boettner and L. Van Aelst The Rap GTPase Activator Drosophila PDZ-GEF Regulates Cell Shape in Epithelial Migration and Morphogenesis Mol. Cell. Biol., November 15, 2007; 27(22): 7966 - 7980. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Williams Drosophila Hemopoiesis and Cellular Immunity J. Immunol., April 15, 2007; 178(8): 4711 - 4716. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Williams, M. S. Habayeb, and D. Hultmark Reciprocal regulation of Rac1 and Rho1 in Drosophila circulating immune surveillance cells J. Cell Sci., February 1, 2007; 120(3): 502 - 511. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Ninov, D. A. Chiarelli, and E. Martin-Blanco Extrinsic and intrinsic mechanisms directing epithelial cell sheet replacement during Drosophila metamorphosis Development, January 15, 2007; 134(2): 367 - 379. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Huelsmann, C. Hepper, D. Marchese, C. Knoll, and R. Reuter The PDZ-GEF Dizzy regulates cell shape of migrating macrophages via Rap1 and integrins in the Drosophila embryo Development, August 1, 2006; 133(15): 2915 - 2924. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Williams, M.-L. Wiklund, S. Wikman, and D. Hultmark Rac1 signalling in the Drosophila larval cellular immune response J. Cell Sci., May 15, 2006; 119(10): 2015 - 2024. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Wood, C. Faria, and A. Jacinto Distinct mechanisms regulate hemocyte chemotaxis during development and wound healing in Drosophila melanogaster J. Cell Biol., May 8, 2006; 173(3): 405 - 416. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Williams, I. Ando, and D. Hultmark Drosophila melanogaster Rac2 is necessary for a proper cellular immune response Genes Cells, August 1, 2005; 10(8): 813 - 823. [Abstract] [Full Text] [PDF] |
||||