scholarly journals Dual function of the region-specific homeotic gene spalt during Drosophila tracheal system development

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2215-2223 ◽  
Author(s):  
R.P. Kuhnlein ◽  
R. Schuh
Keyword(s):  
Cell Migration ◽  
System Development ◽  
Dual Function ◽  
Homeotic Gene ◽  
Tracheal System ◽  
Directed Migration ◽  
Tracheal Cell ◽  
Distinct Subset ◽  
Directed Cell Migration ◽  
Placode Formation

We report that the region-specific homeotic gene spalt affects the Drosophila tracheal system at two different stages of embryonic development. Both lack-of-function and gain-of-function experiments show that blastodermal spalt activity restricts tracheal development to 10 bilaterally positioned pairs of tracheal placodes in the trunk region by repressing placode formation in parasegments 2, 3 and 14. The results suggest that the activity of the zinc-finger type transcription factor encoded by spalt suppresses the molecular pathway that establishes tracheal development. spalt function is also necessary for the directed migration of the dorsal trunk cells, a distinct subset of tracheal cells. This process is a prerequisite for the formation of the dorsal trunk generated by fusion of adjacent tracheal metameres into a common tubular structure. The directed cell migration, in which spalt gene function participates, seems to be independent of branch fusion and general tracheal cell migration processes.

ribbon encodes a novel BTB/POZ protein required for directed cell migration in Drosophila melanogaster

Development ◽  
2001 ◽  
Vol 128 (15) ◽  
pp. 3001-3015 ◽  
Author(s):  
Pamela L. Bradley ◽  
Deborah J. Andrew
Keyword(s):  
Cell Migration ◽  
Wnt Signaling ◽  
Signaling Pathways ◽  
Egf Receptor ◽  
Tracheal System ◽  
Directed Cell Migration ◽  
Posterior Migration ◽  
And Function ◽  
Dorsal Epidermis ◽  
Anterior Posterior

During development, directed cell migration is crucial for achieving proper shape and function of organs. One well-studied example is the embryonic development of the larval tracheal system of Drosophila, in which at least four signaling pathways coordinate cell migration to form an elaborate branched network essential for oxygen delivery throughout the larva. FGF signaling is required for guided migration of all tracheal branches, whereas the DPP, EGF receptor, and Wingless/WNT signaling pathways each mediate the formation of specific subsets of branches. Here, we characterize ribbon, which encodes a BTB/POZ-containing protein required for specific tracheal branch migration. In ribbon mutant tracheae, the dorsal trunk fails to form, and ventral branches are stunted; however, directed migrations of the dorsal and visceral branches are largely unaffected. The dorsal trunk also fails to form when FGF or Wingless/WNT signaling is lost, and we show that ribbon functions downstream of, or parallel to, these pathways to promote anterior-posterior migration. Directed cell migration of the salivary gland and dorsal epidermis are also affected in ribbon mutants, suggesting that conserved mechanisms may be employed to orient cell migrations in multiple tissues during development.

ventral veinless, a POU domain transcription factor, regulates different transduction pathways required for tracheal branching in Drosophila

Development ◽  
1997 ◽  
Vol 124 (17) ◽  
pp. 3273-3281 ◽  
Author(s):  
M. Llimargas ◽  
J. Casanova
Keyword(s):  
Cell Migration ◽  
Target Genes ◽  
Branching Pattern ◽  
Specific Expression ◽  
Tracheal System ◽  
Tracheal Cell ◽  
Pou Domain ◽  
Tracheal Branching ◽  
Multicellular Organisms

Cell migration is an important step in a variety of developmental processes in many multicellular organisms. A particularly appropriate model to address the study of cell migration is the tracheal system of Drosophila, whose formation occurs by migration and fusion from clusters of ectodermal cells specified in each side of ten embryonic segments. Morphogenesis of the tracheal tree requires the activity of many genes, among them breathless (btl) and ventral veinless (vvl) whose mutations abolish tracheal cell migration. Activation of the btl receptor by branchless (bnl), its putative ligand, exerts an instructive role in the process of guiding tracheal cell migration. vvl has been shown to be required for the maintenance of btl expression during tracheal tree formation. Here we show that, in addition, vvl is independently required for the specific expression in the tracheal cells of thick veins (tkv) and rhomboid (rho), two genes whose mutations disrupt only particular branches of the tracheal system. Indeed, we show that expression in the tracheal cells of an activated form of tkv, the putative decapentaplegic (dpp) receptor, is able to induce shifts in their migration, asserting the role of the dpp pathway in establishing the branching pattern of the tracheal tree. In addition, by ubiquitous expression of the btl and tkv genes in vvl mutant embryos we show that both genes contribute to vvl function. These results indicate that through activation of its target genes, vvl makes the tracheal cells competent to further signalling and suggest that the btl transduction pathway could collaborate with other transduction pathways also regulated by vvl to specify the tracheal branching pattern.

Hedgehog signaling patterns the tracheal branches

Development ◽  
2001 ◽  
Vol 128 (9) ◽  
pp. 1599-1606 ◽  
Author(s):  
L. Glazer ◽  
B.Z. Shilo
Keyword(s):  
Cell Migration ◽  
Hedgehog Signaling ◽  
Egf Receptor ◽  
Cell Types ◽  
Fixed Number ◽  
Branching Pattern ◽  
Tracheal System ◽  
Tracheal Cell ◽  
Distinct Cell

The elaborate branching pattern of the Drosophila tracheal system originates from ten tracheal placodes on both sides of the embryo, each consisting of about 80 cells. Simultaneous cell migration from each tracheal pit in six different directions gives rise to the stereotyped branching pattern. Each branch contains a fixed number of cells. Previous work has shown that in the dorsoventral axis, localized activation of the Dpp, Wnt and EGF receptor (DER) pathways, subdivides the tracheal pit into distinct domains. We present the role of the Hedgehog (Hh) signaling system in patterning the tracheal branches. Hh is expressed in segmental stripes abutting the anterior border of the tracheal placodes. Induction of patched expression, which results from activation by Hh, demonstrates that cells in the anterior half of the tracheal pit are activated. In hh-mutant embryos migration of all tracheal branches is absent or stalled. These defects arise from a direct effect of Hh on tracheal cells, rather than by indirect effects on patterning of the ectoderm. Tracheal cell migration could be rescued by expressing Hh only in the tracheal cells, without rescuing the ectodermal defects. Signaling by several pathways, including the Hh pathway, thus serves to subdivide the uniform population of tracheal cells into distinct cell types that will subsequently be recruited into the different branches.

Control of tracheal tubulogenesis by Wingless signaling

Development ◽  
2000 ◽  
Vol 127 (20) ◽  
pp. 4433-4442 ◽  
Author(s):  
T. Chihara ◽  
S. Hayashi
Keyword(s):  
Tubular Epithelium ◽  
Signal Transducer ◽  
Tracheal System ◽  
Multiple Functions ◽  
Directed Migration ◽  
Tracheal Cell ◽  
Wingless Signaling ◽  
Unique Identity ◽  
Intracellular Signal

The tubular epithelium of the Drosophila tracheal system forms a network with a stereotyped pattern consisting of cells and branches with distinct identity. The tracheal primordium undergoes primary branching induced by the FGF homolog Branchless, differentiates cells with specialized functions such as fusion cells, which perform target recognition and adhesion during branch fusion, and extends branches toward specific targets. Specification of a unique identity for each primary branch is essential for directed migration, as a defect in either the EGFR or the Dpp pathway leads to a loss of branch identity and the misguidance of tracheal cell migration. Here, we investigate the role of Wingless signaling in the specification of cell and branch identity in the tracheal system. Wingless and its intracellular signal transducer, Armadillo, have multiple functions, including specifying the dorsal trunk through activation of Spalt expression and inducing differentiation of fusion cells in all fusion branches. Moreover, we show that Wingless signaling regulates Notch signaling by stimulating delta expression at the tip of primary branches. These activities of Wingless signaling together specify the shape of the dorsal trunk and other fusion branches.

scholarly journals Excitable Networks in Directed Cell Migration

2021 ◽  
Vol 120 (3) ◽  
pp. 112a-113a
Author(s):  
Peter N. Devreotes ◽  
Tatsat Banerjee ◽  
Dhiman S. Pal ◽  
Debojyoti Biswas ◽  
Huiwang Zhan ◽  
...  
Keyword(s):  
Cell Migration ◽  
Directed Cell Migration

The atypical Rho GTPase RhoD is a regulator of actin cytoskeleton dynamics and directed cell migration

2017 ◽  
Vol 352 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Magdalena Blom ◽  
Katarina Reis ◽  
Johan Heldin ◽  
Johan Kreuger ◽  
Pontus Aspenström
Keyword(s):  
Cell Migration ◽  
Actin Cytoskeleton ◽  
Rho Gtpase ◽  
Directed Cell Migration ◽  
Cytoskeleton Dynamics

scholarly journals The Drosophila SRF homolog is expressed in a subset of tracheal cells and maps within a genomic region required for tracheal development

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 743-753 ◽  
Author(s):  
M. Affolter ◽  
J. Montagne ◽  
U. Walldorf ◽  
J. Groppe ◽  
U. Kloter ◽  
...  
Keyword(s):  
Serum Response Factor ◽  
Genomic Region ◽  
Nucleotide Sequence Analysis ◽  
Germ Band ◽  
Correct Position ◽  
Tracheal System ◽  
Sequence Identity ◽  
Distinct Subset ◽  
Drosophila Homolog ◽  
Serum Response

The Drosophila homolog of the vertebrate serum response factor (SRF) was isolated by low stringency hybridization. Nucleotide sequence analysis revealed that the Drosophila SRF homolog (DSRF) codes for a protein that displays 93% sequence identity with human SRF in the MADS domain, the region required for DNA binding, dimerization and interaction with accessory factors. The DSRF gene is expressed during several phases of embryonic development. In the egg, both the RNA and the protein are maternal in origin and slowly decrease in amount during gastrulation. After germ band retraction, high levels of zygotic expression are observed in a distinct subset of peripheral tracheal cells distributed throughout the embryo. Many of these cells are at the tip of tracheal branches and are in direct contact with the target tissues. The DSRF gene was mapped to position 60C on the second chromosome, and overlapping deficiencies which remove the gene were identified. Analysis of tracheal development in embryos carrying these deletions revealed a degeneration of most of the major branches of the tracheal system. Although the initial migration of tracheal cells was not affected in those deficient embryos, many tracheal cells appeared not to maintain their correct position and continued to migrate. Thus, the DSRF gene might play a role in the proper formation and maintenance of the trachea.

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