scholarly journals The function of engrailed and the specification of Drosophila wing pattern

Development ◽  
1995 ◽  
Vol 121 (10) ◽  
pp. 3447-3456 ◽  
Author(s):  
I. Guillen ◽  
J.L. Mullor ◽  
J. Capdevila ◽  
E. Sanchez-Herrero ◽  
G. Morata ◽  
...  
Keyword(s):  
Wing Disc ◽  
Gene Products ◽  
Wing Pattern ◽  
Related Gene ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Drosophila Wing ◽  
Partial Inactivation ◽  
Autoregulatory Mechanism ◽  
Adult Drosophila

The adult Drosophila wing (as the other appendages) is subdivided into anterior and posterior compartments that exhibit characteristic patterns. The engrailed (en) gene has been proposed to be paramount in the specification of the posterior compartment identity. Here, we explore the adult en function by targeting its expression in different regions of the wing disc. In the anterior compartment, ectopic en expression gives rise to the substitution of anterior structures by posterior ones, thus demonstrating its role in specification of posterior patterns. The en-expressing cells in the anterior compartment also induce high levels of the hedgehog (hh) and decapentaplegic (dpp) gene products, which results in local duplications of anterior patterns. Besides, hh is able to activate en and the engrailed-related gene invected (inv) in this compartment. In the posterior compartment we find that elevated levels of en product result in partial inactivation of the endogenous en and inv genes, indicating the existence of a negative autoregulatory mechanism. We propose that en has a dual role: a general one for patterning of the appendage, achieved through the activation of secreted proteins like hh and dpp, and a more specific one, determining posterior identity, in which the inv gene may be implicated.

Regeneration from duplicating fragments of the Drosophila wing disc

Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 117-126
Author(s):  
Jane Karlsson ◽  
R. J. Smith
Keyword(s):  
Imaginal Disc ◽  
General Rule ◽  
Wing Disc ◽  
The Other ◽  
Posterior Compartment ◽  
Drosophila Wing ◽  
Polar Coordinate ◽  
New Type ◽  
Coordinate Model

It is a general rule that of two complementary Drosophila imaginal disc fragments, one regenerates and the other duplicates. This paper reports an investigation of an exception to this rule. Duplicating fragments from the periphery of the wing disc which lacked presumptive notum were found to regenerate notum structures during and after duplication. The propensity for this was greatest in fragments lying close to the presumptive notum, with the exception of a fragment confined to the posterior compartment, which did not regenerate notum. Structures were added sequentially, and regeneration stopped once most of the notum was present. These results are not easily explained by the polar coordinate model, which states that regeneration cannot occur from duplicating fragments. Since compartments appear to be involved in this type of regeneration as in others, it is suggested that a new type of model is required, one which permits simultaneous regeneration and duplication, and assigns a major role to compartments.

scholarly journals Effect of abx, bx and pbx mutations on expression of homeotic genes in Drosophila larvae.

Genetics ◽  
1990 ◽  
Vol 124 (4) ◽  
pp. 899-908 ◽  
Author(s):  
J W Little ◽  
C A Byrd ◽  
D L Brower
Keyword(s):  
Ectopic Expression ◽  
Wing Disc ◽  
Homeotic Genes ◽  
Wild Type ◽  
Posterior Compartment ◽  
Altered Expression ◽  
Anterior Compartment ◽  
Regulatory Domains ◽  
Wild Type Phenotype ◽  
Drosophila Larvae

Abstract We have examined the patterns of expression of the homeotic gene Ubx in imaginal discs of Drosophila larvae carrying mutations in the abx, bx and pbx regulatory domains. In haltere discs, all five bx insertion mutations examined led to a general reduction in Ubx expression in the anterior compartment; for a given allele, the strength of the adult cuticle phenotype correlated with the degree of Ubx reduction. Deletions mapping near or overlapping the sites of bx insertions, including three abx alleles and the bx34e-prv(bx-prv) allele, showed greatly reduced Ubx expression in parts of the anterior compartment of the haltere disc; however, anterior patches of strong Ubx expression often remained, in highly variable patterns. As expected, the pbx1 mutation led to reduced Ubx expression in the posterior compartment of the haltere disc; surprisingly, pbx1 also led to altered expression of the en protein near the compartment border in the central region of the disc. In the metathoracic leg, all the bx alleles caused extreme reduction in Ubx expression in the anterior regions, with no allele-specific differences. In contrast, abx and bx-prv alleles resulted in patchy anterior reductions in third leg discs. In the larval central nervous system, abx but not bx alleles affected Ubx expression; the bx-prv deletion gave a wild-type phenotype, but it could not fully complement abx mutations. In the posterior wing disc, the bx-prv allele, and to a much lesser extent the bx34e chromosome from which it arose, led to ectopic expression of Ubx. Unlike other grain-of-function mutations in the BX-C, this phenotype appeared to be partially recessive to wild type. Finally, we asked whether the ppx transformation, which results from early lack of Ubx+ function in the mesothorax and is seen in abx animals, is due to ectopic Scr expression. Some mesothoracic leg and wing discs from abx2 larvae displayed ectopic expression of Scr, which was variable in extent but always confined to the posterior compartment.

Creating a Drosophila wing de novo, the role of engrailed, and the compartment border hypothesis

Development ◽  
1995 ◽  
Vol 121 (10) ◽  
pp. 3359-3369 ◽  
Author(s):  
T. Tabata ◽  
C. Schwartz ◽  
E. Gustavson ◽  
Z. Ali ◽  
T.B. Kornberg
Keyword(s):  
Imaginal Disc ◽  
De Novo ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Drosophila Wing ◽  
Organizational Feature ◽  
Wing Discs ◽  
Mutant Cells ◽  
Anterior Posterior

Anterior/posterior compartment borders bisect every Drosophila imaginal disc, and the engrailed gene is essential for their function. We analyzed the role of the engrailed and invected genes in wing discs by eliminating or increasing their activity. Removing engrailed/invected from posterior wing cells created two new compartments: an anterior compartment consisting of mutant cells and a posterior compartment that grew from neighboring cells. In some cases, these compartments formed a complete new wing. Increasing engrailed activity also affected patterning. These findings demonstrate that engrailed both directs the posterior compartment pathway and creates the compartment border. These findings also establish the compartment border as the pre-eminent organizational feature of disc growth and patterning.

scholarly journals Hedgehog produced by the Drosophila wing imaginal disc induces distinct expression responses in three target tissues

2020 ◽  
Author(s):  
Ryo Hatori ◽  
Thomas B. Kornberg
Keyword(s):  
Imaginal Disc ◽  
Wing Disc ◽  
Wing Imaginal Disc ◽  
Cell Type ◽  
Concentration Gradients ◽  
Anterior Compartment ◽  
Animal Development ◽  
Drosophila Wing ◽  
Evolutionarily Conserved ◽  
Cell Type Specific

AbstractHedgehog (Hh) is an evolutionarily conserved signaling protein that has essential roles in animal development and homeostasis. We investigated Hh signaling in the region of the Drosophila wing imaginal disc that produces Hh and is near the tracheal air sac primordium (ASP) and myoblasts. Hh distributes in concentration gradients in the wing disc anterior compartment, ASP, and myoblasts and activates different sets of genes in each tissue. Some transcriptional targets of Hh signal transduction are common to the disc, ASP, and myoblasts, whereas others are tissue-specific. Signaling in the three tissues is cytoneme-mediated and cytoneme-dependent. We conclude that a single source of Hh in the wing disc regulates cell type-specific responses in three discreet target tissues.SummaryHedgehog produced by the wing imaginal disc signals to wing disc, myoblast and tracheal cells

groucho and hedgehog regulate engrailed expression in the anterior compartment of the Drosophila wing

Development ◽  
1995 ◽  
Vol 121 (10) ◽  
pp. 3467-3476 ◽  
Author(s):  
J.F. de Celis ◽  
M. Ruiz-Gomez
Keyword(s):  
Cell Growth ◽  
Normal Growth ◽  
Wing Disc ◽  
Anterior Compartment ◽  
Drosophila Wing ◽  
Compartment Boundary ◽  
Ectopic Activation ◽  
Selector Genes ◽  
Dorsoventral Boundary ◽  
Anterior Posterior

Drosophila imaginal discs are divided into units called compartments. Cells belonging to the same compartment are related by lineage and express a characteristic set of ‘selector genes’. The borders between compartments act as organizing centres that influence cell growth within compartments. Thus, in the cells immediately anterior to the anterior-posterior compartment boundary the presence of the hedgehog product causes expression of decapentaplegic, which, in turn, influences the growth and patterning of the wing disc. The normal growth of the disc requires that posterior-specific genes, such as hedgehog and engrailed are not expressed in cells of the anterior compartment. Here we show that hedgehog can activate engrailed in the anterior compartment and that both hedgehog and engrailed are specifically repressed in anterior cells by the activity of the neurogenic gene groucho. In groucho mutant discs, hedgehog and engrailed are expressed at the dorsoventral boundary of the anterior compartment, leading to the ectopic activation of decapentaplegic and patched and to a localised increase in cell growth associated with pattern duplications. The presence of engrailed in the anterior compartment causes the transformation of anterior into posterior structures.

scholarly journals Dpp from the anterior stripe of cells is crucial for the growth of the Drosophila wing disc

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Shinya Matsuda ◽  
Markus Affolter
Keyword(s):  
Null Allele ◽  
Growth Control ◽  
Wing Disc ◽  
The Other ◽  
Morphogen Gradient ◽  
Posterior Compartment ◽  
Time Points ◽  
Larval Stages ◽  
Drosophila Wing ◽  
Control Growth

The Dpp morphogen gradient derived from the anterior stripe of cells is thought to control growth and patterning of the Drosophila wing disc. However, the spatial-temporal requirement of dpp for growth and patterning remained largely unknown. Recently, two studies re-addressed this question. By generating a conditional null allele, one study proposed that the dpp stripe is critical for patterning but not for growth (Akiyama and Gibson, 2015). In contrast, using a membrane-anchored nanobody to trap Dpp, the other study proposed that Dpp dispersal from the stripe is required for patterning and also for medial wing disc growth, at least in the posterior compartment (Harmansa et al., 2015). Thus, growth control by the Dpp morphogen gradient remains under debate. Here, by removing dpp from the stripe at different time points, we show that the dpp stripe source is indeed required for wing disc growth, also during third instar larval stages.

scholarly journals Membrane potential regulates Hedgehog signaling and compartment boundary maintenance in the Drosophila wing disc

2020 ◽  
Author(s):  
Maya Emmons-Bell ◽  
Riku Yasutomi ◽  
Iswar K. Hariharan
Keyword(s):  
Membrane Potential ◽  
Hedgehog Signaling ◽  
Membrane Depolarization ◽  
Wing Disc ◽  
Anterior Compartment ◽  
Drosophila Wing ◽  
Compartment Boundary ◽  
Boundary Maintenance ◽  
Elevated Expression ◽  
Hh Signaling

AbstractThe Drosophila wing imaginal disc is composed of two lineage-restricted populations of cells separated by a smooth boundary. Hedgehog (Hh) from posterior cells activates a signaling pathway in anterior cells near the boundary which is necessary for boundary maintenance. Here, we show that membrane potential is patterned in the wing disc. Anterior cells near the boundary, where Hh signaling is most active, are more depolarized than posterior cells across the boundary. Elevated expression of the ENaC channel Ripped Pocket (Rpk), observed in these anterior cells, requires Hh. Antagonizing Rpk reduces depolarization and disrupts the compartment boundary. Using genetic and optogenetic manipulations, we show that membrane depolarization promotes membrane localization of Smoothened and augments Hh signaling. Thus, membrane depolarization and Hh-dependent signaling mutually reinforce each other in this region. Finally, clones of depolarized cells survive preferentially in the anterior compartment and clones of hyperpolarized cells survive preferentially in the posterior compartment.

Quantitative EM of gap junction distribution in mutant drosophila wing discs

1983 ◽  
Vol 41 ◽  
pp. 720-721
Author(s):  
J.S. Ryerse
Keyword(s):  
Gap Junctions ◽  
Growth Control ◽  
Intercellular Junctions ◽  
Wing Disc ◽  
En Bloc ◽  
Metabolic Cooperation ◽  
Drosophila Wing ◽  
Adult Wing ◽  
Wing Discs ◽  
Wing Pouch

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.

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