Discovery of wing imaginal discs in the penultimate instar of the lacewing
            Mallada desjardinsi
            (Insecta: Neuroptera: Chrysopidae) with histological notes on postembryonic imaginal disc development

Hedgehog (Hh) is a secreted morphogen involved in both short- and long-range signaling necessary for tissue patterning during development. It is unclear how this dually lipidated protein is transported over a long range in the aqueous milieu of interstitial spaces. We previously showed that the long-range signaling of Hh requires its oligomerization. Here we show that Hh is secreted in the form of exovesicles. These are derived by the endocytic delivery of cell surface Hh to multivesicular bodies (MVBs) via an endosomal sorting complex required for transport (ECSRT)–dependent process. Perturbations of ESCRT proteins have a selective effect on long-range Hh signaling in Drosophila wing imaginal discs. Of importance, oligomerization-defective Hh is inefficiently incorporated into exovesicles due to its poor endocytic delivery to MVBs. These results provide evidence that nanoscale organization of Hh regulates the secretion of Hh on ESCRT-derived exovesicles, which in turn act as a vehicle for long-range signaling.

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The Serrate locus of Drosophila and its role in morphogenesis of the wing imaginal discs: control of cell proliferation

Development ◽

10.1242/dev.120.3.535 ◽

1994 ◽

Vol 120 (3) ◽

pp. 535-544 ◽

Cited By ~ 38

Author(s):

S.A. Speicher ◽

U. Thomas ◽

U. Hinz ◽

E. Knust

Keyword(s):

Cell Proliferation ◽

Transmembrane Protein ◽

Ectopic Expression ◽

Imaginal Discs ◽

Specific Cell ◽

Loss Of Function ◽

Severe Reduction ◽

Homozygous Mutant ◽

Wing Imaginal Discs ◽

Larval Lethality

The Drosophila gene Serrate encodes a transmembrane protein with 14 EGF-like repeats in its extracellular domain. Here we show that loss-of-function mutations in this gene lead to larval lethality. Homozygous mutant larvae fail to differentiate the anterior spiracles, exhibit poorly developed mouth-hooks and show a severe reduction in the size of the wing and haltere primordia, which is not due to cell death. The few homozygous mutant escapers that pupariate develop into pharate adults that almost completely lack wings and halteres. Clonal analysis in the adult epidermis demonstrates a requirement for Serrate during wing and haltere development. Targeted ectopic expression of Serrate in the imaginal discs using the yeast transcriptional activator Gal4 results in regionally restricted induction of cell proliferation, e.g. the ventral tissues in the case of the wings and halteres. The results suggest that the wild-type function of Serrate is required for the control of position-specific cell proliferation during development of meso- and metathoracic dorsal discs, which in turn exerts a direct effect on morphogenesis.

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Role of D-GADD45 in JNK-Dependent Apoptosis and Regeneration in Drosophila

Genes ◽

10.3390/genes10050378 ◽

2019 ◽

Vol 10 (5) ◽

pp. 378 ◽

Cited By ~ 2

Author(s):

Carlos Camilleri-Robles ◽

Florenci Serras ◽

Montserrat Corominas

Keyword(s):

Cell Cycle ◽

Cell Death ◽

Cell Cycle Control ◽

Imaginal Discs ◽

Cellular Functions ◽

Correct Function ◽

Response To Stress ◽

Wing Imaginal Discs ◽

Harmful Effects

The GADD45 proteins are induced in response to stress and have been implicated in the regulation of several cellular functions, including DNA repair, cell cycle control, senescence, and apoptosis. In this study, we investigate the role of D-GADD45 during Drosophila development and regeneration of the wing imaginal discs. We find that higher expression of D-GADD45 results in JNK-dependent apoptosis, while its temporary expression does not have harmful effects. Moreover, D-GADD45 is required for proper regeneration of wing imaginal discs. Our findings demonstrate that a tight regulation of D-GADD45 levels is required for its correct function both, in development and during the stress response after cell death.

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