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.

Role of knot (kn) in Wing Patterning in Drosophila

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1203-1212 ◽  
Author(s):  
Katerina Nestoras ◽  
Helena Lee ◽  
Jym Mohler
Keyword(s):  
Hedgehog Signaling ◽  
Imaginal Disc ◽  
Hedgehog Signaling Pathway ◽  
Posterior Compartment ◽  
Drosophila Wing ◽  
Compartment Boundary ◽  
Hh Signaling ◽  
Embryonic Segmentation ◽  
Anterior Posterior

We have undertaken a genetic analysis of new strong alleles of knot (kn). The original kn1 mutation causes an alteration of wing patterning similar to that associated with mutations of fused (fu), an apparent fusion of veins 3 and 4 in the wing. However, unlike fu, strong kn mutations do not affect embryonic segmentation and indicate that kn is not a component of a general Hh (Hedgehog)-signaling pathway. Instead we find that kn has a specific role in those cells of the wing imaginal disc that are subject to ptc-mediated Hh-signaling. Our results suggest a model for patterning the medial portion of the Drosophila wing, whereby the separation of veins 3 and 4 is maintained by kn activation in the intervening region in response to Hh-signaling across the adjacent anterior-posterior compartment boundary.

Positional signaling by hedgehog in Drosophila imaginal disc development

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A.L. Felsenfeld ◽  
J.A. Kennison
Keyword(s):  
Hedgehog Signaling ◽  
Imaginal Disc ◽  
Ectopic Expression ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Segment Polarity ◽  
Wing Structures ◽  
Wing Discs ◽  
Segment Polarity Gene ◽  
Polarity Gene

We describe a dominant gain-of-function allele of the segment polarity gene hedgehog. This mutation causes ectopic expression of hedgehog mRNA in the anterior compartment of wing discs, leading to overgrowth of tissue in the anterior of the wing and partial duplication of distal wing structures. The posterior compartment of the wing is unaffected. Other imaginal derivatives are affected, resulting in duplications of legs and antennae and malformations of eyes. In mutant imaginal wing discs, expression of the decapentaplegic gene, which is implicated in the hedgehog signaling pathway, is also perturbed. The results suggest that hedgehog protein acts in the wing as a signal to instruct neighboring cells to adopt fates appropriate to the region of the wing just anterior to the compartmental boundary.

engrailed and polyhomeotic interactions are required to maintain the A/P boundary of the Drosophila developing wing

Development ◽  
1998 ◽  
Vol 125 (15) ◽  
pp. 2771-2780 ◽  
Author(s):  
F. Maschat ◽  
N. Serrano ◽  
N.B. Randsholt ◽  
G. Geraud
Keyword(s):  
Cell Fate ◽  
Regulatory Protein ◽  
Polycomb Group ◽  
Posterior Compartment ◽  
Cubitus Interruptus ◽  
Anterior Compartment ◽  
Embryonic Segmentation ◽  
Wing Morphogenesis ◽  
Anterior Posterior

Engrailed is a nuclear regulatory protein with essential roles in embryonic segmentation and wing morphogenesis. One of its regulatory targets in embryos was shown to be the Polycomb group gene, polyhomeotic. We show here that transheterozygous adult flies, mutant for both engrailed and polyhomeotic, show a gap in the fourth vein. In the corresponding larval imaginal discs, a polyhomeotic-lacZ enhancer trap is not normally activated in anterior cells adjacent to the anterior-posterior boundary. This intermediary region corresponds to the domain of low engrailed expression that appears in the anterior compartment, during L3. Several arguments show that engrailed is responsible for the induction of polyhomeotic in these cells. The role of polyhomeotic in this intermediary region is apparently to maintain the repression of hedgehog in the anterior cells abutting the anterior-posterior boundary, since these cells ectopically express hedgehog when polyhomeotic is not activated. This leads to ectopic expressions first of patched, then of cubitus interruptus and decapentaplegic in the posterior compartment, except for the dorsoventral border cells that are not affected. Thus posterior cells express a new set of genes that are normally characteristic of anterior cells, suggesting a change in the cell identity. Altogether, our data indicate that engrailed and polyhomeotic interactions are required to maintain the anterior-posterior boundary and the posterior cell fate, just prior to the evagination of the wing.

Signaling through both type I DPP receptors is required for anterior-posterior patterning of the entire Drosophila wing

Development ◽  
1997 ◽  
Vol 124 (1) ◽  
pp. 79-89 ◽  
Author(s):  
M.A. Singer ◽  
A. Penton ◽  
V. Twombly ◽  
F.M. Hoffmann ◽  
W.M. Gelbart
Keyword(s):  
Cell Fate ◽  
Type I ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Hypomorphic Allele ◽  
Compartment Boundary ◽  
Adult Wing ◽  
Mutant Cells ◽  
Narrow Stripe ◽  
Anterior Posterior

The imaginal disk expression of the TGF-beta superfamily member DPP in a narrow stripe of cells along the anterior-posterior compartment boundary is essential for proper growth and patterning of the Drosophila appendages. We examine DPP receptor function to understand how this localized DPP expression produces its global effects upon appendage development. Clones of saxophone (sax) or thick veins (tkv) mutant cells, defective in one of the two type I receptors for DPP, show shifts in cell fate along the anterior-posterior axis. In the adult wing, clones that are homozygous for a null allele of sax or a hypomorphic allele of tkv show shifts to more anterior fates when the clone is in the anterior compartment and to more posterior fates when the clone is in the posterior compartment. The effect of these clones upon the expression pattern of the downstream gene spalt-major also correlates with these specific shifts in cell fate. The similar effects of sax null and tkv hypomorphic clones indicate that the primary difference in the function of these two receptors during wing patterning is that TKV transmits more of the DPP signal than does SAX. Our results are consistent with a model in which a gradient of DPP reaches all cells in the developing wing blade to direct anterior-posterior pattern.

scholarly journals Modified laparoscopic lateral suspension with a five-arm mesh in pelvic organ prolapse surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Eren Akbaba ◽  
Burak Sezgin
Keyword(s):  
Pelvic Organ Prolapse ◽  
De Novo ◽  
Pelvic Organ ◽  
Laparoscopic Technique ◽  
Life Questionnaire ◽  
Advanced Stage ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Mesh Graft ◽  
Laparoscopic Lateral Suspension

Abstract Background Laparoscopic lateral suspension (LLS) is a laparoscopic technique used to treat pelvic organ prolapse (POP) in apical and anterior compartment defect with the use of a synthetic T-shaped mesh graft. The posterior compartment is repaired using a second mesh or a procedure along with LLS, such as posterior colporrhaphy. The aim of this study was to evaluate the clinical results of LLS for POP using a five-arm mesh instead of a T-shaped mesh graft to repair the defect of the posterior compartment in addition to the apical and anterior compartments. Methods Data from 37 patients with a diagnosis of advanced-stage (≥ 3) POP undergoing LLS with the use of a five-arm mesh were retrospectively analysed. Pre-operative and post-operative examinations and, surgical outcomes were determined. The results of measurements and examinations, reoperation rates, erosion rates, lower urinary tract symptoms, and complications were analysed. The Prolapse Quality of Life Questionnaire (P-QOL) was also used. Results The median post-operative follow-up was 20 (13–34) months. There was a significant improvement in POP-Q scores in all treated compartments, with overall objective cure rates of 94.5% for the apical compartment, 86.4% for the anterior compartment, and 91.8% for the posterior compartment. The median operative time was 96 (76–112) minutes. The median length of hospitalization was 2 (1–3) days. A significant improvement in vaginal bulge, urinary urgency, incomplete voiding, urinary frequency, and constipation was observed after surgery. The sexuality among patients increased from 13 (35.1%) preoperatively to 22 (59.4%) post-operatively. De novo stress urinary incontinence developed in 7 (18.9%) patients. The P-QOL scores improved significantly after surgery. Conclusions In advanced-stage POP patients, the posterior compartment damage can also be repaired in LLS with the use of a single five-arm mesh without the need for an additional procedure, and the recurrence rate can be reduced.

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.

Expression and function of decapentaplegic and thick veins during the differentiation of the veins in the Drosophila wing

Development ◽  
1997 ◽  
Vol 124 (5) ◽  
pp. 1007-1018 ◽  
Author(s):  
J.F. Celis de
Keyword(s):  
Imaginal Disc ◽  
Signal Transduction Pathways ◽  
Pupal Development ◽  
Transmembrane Receptors ◽  
Notch Ligand ◽  
Regulatory Interactions ◽  
Drosophila Wing ◽  
Signalling Molecule ◽  
And Function

The differentiation of the veins in the Drosophila wing involves the coordinate activities of several signal transduction pathways, including those mediated by the transmembrane receptors Torpedo and Notch. In this report, the role of the signalling molecule Decapentaplegic during vein differentiation has been analysed. It is shown that decapentaplegic is expressed in the pupal veins under the control of genes that establish vein territories in the imaginal disc. Decapentaplegic, acting through its receptor Thick veins, activates vein differentiation and restricts expression of both veinlet and the Notch-ligand Delta to the developing veins. Genetic combinations between mutations that increase or reduce Notch, veinlet and decapentaplegic activities suggest that the maintenance of the vein differentiation state during pupal development involves cross-regulatory interactions between these pathways.

Hedgehog is required for activation of engrailed during regeneration of fragmented Drosophila imaginal discs

Development ◽  
1999 ◽  
Vol 126 (8) ◽  
pp. 1591-1599 ◽  
Author(s):  
M.C. Gibson ◽  
G. Schubiger
Keyword(s):  
Normal Growth ◽  
Imaginal Discs ◽  
Ideal Model ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
In Vivo Culture ◽  
Pattern Regulation ◽  
Regulative Capacity ◽  
Anterior Posterior

Surgically fragmented Drosophila appendage primordia (imaginal discs) engage in wound healing and pattern regulation during short periods of in vivo culture. Prothoracic leg disc fragments possess exceptional regulative capacity, highlighted by the ability of anterior cells to convert to posterior identity and establish a novel posterior compartment. This anterior/posterior conversion violates developmental lineage restrictions essential for normal growth and patterning of the disc, and thus provides an ideal model for understanding how cells change fate during epimorphic pattern regulation. Here we present evidence that the secreted signal encoded by hedgehog directs anterior/posterior conversion by activating the posterior-specific transcription factor engrailed in regulating anterior cells. In the absence of hedgehog activity, prothoracic leg disc fragments fail to undergo anterior/posterior conversion, but can still regenerate missing anterior pattern elements. We suggest that hedgehog-independent regeneration within the anterior compartment (termed integration) is mediated by the positional cues encoded by wingless and decapentaplegic. Taken together, our results provide a novel mechanistic interpretation of imaginal disc pattern regulation and permit speculation that similar mechanisms could govern appendage regeneration in other organisms.

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.

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