Activation and function of Notch at the dorsal-ventral boundary of the wing imaginal disc

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 359-369 ◽  
Author(s):  
J.F. de Celis ◽  
A. Garcia-Bellido ◽  
S.J. Bray

The cells along the dorsoventral boundary of the Drosophila wing imaginal disc have distinctive properties and their specification requires Notch activity. Later in development, these cells will form the wing margin, where sensory organs and specialised trichomes appear in a characteristic pattern. We find that Notch is locally activated in these cells, as demonstrated by the restricted expression of the Enhancer of split proteins in dorsal and ventral cells abutting the D/V boundary throughout the third larval instar. Furthermore other genes identified by their involvement in Notch signaling during neurogenesis, such as Delta and Suppressor of Hairless, also participate in Notch function at the dorsoventral boundary. In addition, Serrate, a similar transmembrane protein to Delta, behaves as a ligand required in dorsal cells to activate Notch at the boundary. Notch gain-of-function alleles in which Notch activity is not restricted to the dorsoventral boundary cause miss-expression of cut and wingless and overgrowth of the disc, illustrating the importance of localised Notch activation for wing development.

Development ◽  
1998 ◽  
Vol 125 (21) ◽  
pp. 4245-4257 ◽  
Author(s):  
B. Biehs ◽  
M.A. Sturtevant ◽  
E. Bier

Previous studies have suggested that vein primordia in Drosophila form at boundaries along the A/P axis between discrete sectors of the larval wing imaginal disc. Genes involved in initiating vein development during the third larval instar are expressed either in narrow stripes corresponding to vein primordia or in broader ‘provein’ domains consisting of cells competent to become veins. In addition, genes specifying the alternative intervein cell fate are expressed in complementary intervein regions. The regulatory relationships between genes expressed in narrow vein primordia, in broad provein stripes and in interveins remains unknown, however. In this manuscript, we provide additional evidence for veins forming in narrow stripes at borders of A/P sectors. These experiments further suggest that narrow vein primordia produce secondary short-range signal(s), which activate expression of provein genes in a broad pattern in neighboring cells. We also show that crossregulatory interactions among genes expressed in veins, proveins and interveins contribute to establishing the vein-versus-intervein pattern, and that control of gene expression in vein and intervein regions must be considered on a stripe-by-stripe basis. Finally, we present evidence for a second set of vein-inducing boundaries lying between veins, which we refer to as paravein boundaries. We propose that veins develop at both vein and paravein boundaries in more ‘primitive’ insects, which have up to twice the number of veins present in Drosophila. We present a model in which different A/P boundaries organize vein-specific genetic programs to govern the development of individual veins.


Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3263-3268 ◽  
Author(s):  
Marco Milán ◽  
Ulrich Weihe ◽  
Stanley Tiong ◽  
Welcome Bender ◽  
Stephen M. Cohen

Drosophila limbs develop from imaginal discs that are subdivided into compartments. Dorsal-ventral subdivision of the wing imaginal disc depends on apterous activity in dorsal cells. Apterous protein is expressed in dorsal cells and is responsible for (1) induction of a signaling center along the dorsal-ventral compartment boundary (2) establishment of a lineage restriction boundary between compartments and (3) specification of dorsal cell fate. Here, we report that the homeobox gene msh (muscle segment homeobox) acts downstream of apterous to confer dorsal identity in wing development.


Development ◽  
1998 ◽  
Vol 125 (23) ◽  
pp. 4617-4626 ◽  
Author(s):  
J.F. de Celis ◽  
D.M. Tyler ◽  
J. de Celis ◽  
S.J. Bray

The legs of Drosophila are divided into segments along the proximodistal axis by flexible structures called joints. The separation between segments is already visible in the imaginal disc as folds of the epithelium, and cells at segment boundaries have different morphology during pupal development. We find that Notch is locally activated in distal cells of each segment, as demonstrated by the restricted expression of the Enhancer of split mbeta gene, and is required for the formation of normal joints. The genes fringe, Delta, Serrate and Suppressor of Hairless, also participate in Notch function during leg development, and their expression is localised within the leg segments with respect to segment boundaries. The failure to form joints when Notch signalling is compromised leads to shortened legs, suggesting that the correct specification of segment boundaries is critical for normal leg growth. The requirement for Notch during leg development resembles that seen during somite formation in vertebrates and at the dorsal ventral boundary of the wing, suggesting that the creation of boundaries of gene expression through Notch activation plays a conserved role in co-ordinating growth and patterning.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Hai Huang ◽  
Thomas B Kornberg

The flight muscles, dorsal air sacs, wing blades, and thoracic cuticle of the Drosophila adult function in concert, and their progenitor cells develop together in the wing imaginal disc. The wing disc orchestrates dorsal air sac development by producing decapentaplegic and fibroblast growth factor that travel via specific cytonemes in order to signal to the air sac primordium (ASP). Here, we report that cytonemes also link flight muscle progenitors (myoblasts) to disc cells and to the ASP, enabling myoblasts to relay signaling between the disc and the ASP. Frizzled (Fz)-containing myoblast cytonemes take up Wingless (Wg) from the disc, and Delta (Dl)-containing myoblast cytonemes contribute to Notch activation in the ASP. Wg signaling negatively regulates Dl expression in the myoblasts. These results reveal an essential role for cytonemes in Wg and Notch signaling and for a signal relay system in the myoblasts.


2021 ◽  
Vol 22 (5) ◽  
pp. 2732
Author(s):  
Nadine Reichhart ◽  
Vladimir M. Milenkovic ◽  
Christian H. Wetzel ◽  
Olaf Strauß

The anoctamin (TMEM16) family of transmembrane protein consists of ten members in vertebrates, which act as Ca2+-dependent ion channels and/or Ca2+-dependent scramblases. ANO4 which is primarily expressed in the CNS and certain endocrine glands, has been associated with various neuronal disorders. Therefore, we focused our study on prioritizing missense mutations that are assumed to alter the structure and stability of ANO4 protein. We employed a wide array of evolution and structure based in silico prediction methods to identify potentially deleterious missense mutations in the ANO4 gene. Identified pathogenic mutations were then mapped to the modeled human ANO4 structure and the effects of missense mutations were studied on the atomic level using molecular dynamics simulations. Our data show that the G80A and A500T mutations significantly alter the stability of the mutant proteins, thus providing new perspective on the role of missense mutations in ANO4 gene. Results obtained in this study may help to identify disease associated mutations which affect ANO4 protein structure and function and might facilitate future functional characterization of ANO4.


Development ◽  
2006 ◽  
Vol 133 (22) ◽  
pp. 4421-4426 ◽  
Author(s):  
F. A. Martin ◽  
G. Morata

2010 ◽  
Vol 79 (2) ◽  
pp. 251-261 ◽  
Author(s):  
Erica Rosemond ◽  
Mario Rossi ◽  
Sara M. McMillin ◽  
Marco Scarselli ◽  
Julie G. Donaldson ◽  
...  

Author(s):  
Diana Hamdan ◽  
Lisa A. Robinson

Excessive infiltration of immune cells into the kidney is a key feature of acute and chronic kidney diseases. The family of chemokines are key drivers of this process. CX3CL1 (fractalkine) is one of two unique chemokines synthesized as a transmembrane protein which undergoes proteolytic cleavage to generate a soluble species. Through interacting with its cognate receptor, CX3CR1, CX3CL1 was originally shown to act as a conventional chemoattractant in the soluble form, and as an adhesion molecule in the transmembrane form. Since then, other functions of CX3CL1 beyond leukocyte recruitment have been described, including cell survival, immunosurveillance, and cell-mediated cytotoxicity. This review summarizes diverse roles of CX3CL1 in kidney disease and potential uses as a therapeutic target and novel biomarker. As the CX3CL1-CX3CR1 axis has been shown to contribute to both detrimental and protective effects in various kidney diseases, a thorough understanding of how the expression and function of CX3CL1 are regulated is needed to unlock its therapeutic potential.


Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5157-5165 ◽  
Author(s):  
T. Vernoux ◽  
J. Kronenberger ◽  
O. Grandjean ◽  
P. Laufs ◽  
J. Traas

The process of organ positioning has been addressed, using the pin-formed 1 (pin1) mutant as a tool. PIN1 is a transmembrane protein involved in auxin transport in Arabidopsis. Loss of function severely affects organ initiation, and pin1 mutants are characterised by an inflorescence meristem that does not initiate any flowers, resulting in the formation of a naked inflorescence stem. This phenotype, combined with the proposed role of PIN1 in hormone transport, makes the mutant an ideal tool to study organ formation and phyllotaxis, and here we present a detailed analysis of the molecular modifications at the shoot apex caused by the mutation. We show that meristem structure and function are not severely affected in the mutant. Major alterations, however, are observed at the periphery of the pin1 meristem, where organ initiation should occur. Although two very early markers of organ initiation, LEAFY and AINTEGUMENTA, are expressed at the periphery of the mutant meristem, the cells are not recruited into distinct primordia. Instead a ring-like domain expressing those primordium specific genes is observed around the meristem. This ring-like domain also expresses a boundary marker, CUP-SHAPED COTYLEDON 2, involved in organ separation, showing that the zone at the meristem periphery has a hybrid identity. This implies that PIN1 is not only involved in organ outgrowth, but that it is also necessary for organ separation and positioning. A model is presented in which PIN1 and the local distribution of auxin control phyllotaxis.


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