Role of the gene Miniature in Drosophila wing maturation

Abstract

Summary: Miniature is an extracellular zona pellucida domain-containing protein, required for flattening of pupal wing epithelia in Drosophila. Here, we show that Miniature also plays an important role in the post-eclosion wing maturation processes triggered by the neurohormone bursicon. Wing expansion and epithelial apoptosis are drastically delayed in miniature loss-of-function mutants, and sped up upon overexpression of the protein in wings. Miniature acts upstream from the heterotrimeric Gs protein transducing the bursicon signal in wing epithelia. We propose that Miniature interacts with bursicon and regulates its diffusion through or stability within the wing tissue. genesis 50:525-533, 2012.

The downregulation of the Miniature gene does not replicate Miniature loss-of-function phenotypes in Drosophila melanogaster wing to the full extent

“…If we address to our previous hypothesis again which propose that Miniature can serve as stabilizer of the neurohormone bursicon maintaining its active concentration and providing its diffusion in and through the wing tissue during its maturation [16], this last observation could confirm the «sink» hypothesis in some extent. In this particular experiment miniature expression was downregulated in the posterior wing compartment, while in anterior its levels is considered to be normal.…”

“…In our previous research it was found, that the extracellular Miniature protein is also important for proper progress of the wing maturation of D. melanogaster. This protein is definitely involved in apoptosis of wing epithelial cells, and presumably also in EMT: different miniature mutants (including m 1 loss-of-function allele) showed a delay of apoptosis in their wings normally triggered by bursicon after eclosion of the fly from a pupal case, and they also showed different deviations from normal wing expansion [16], which is used for the indirect investigation of EMT [9].…”

“…So Miniature acts cell-autonomously, but also to a certain extent in a nonautonomous manner within the wing [16].…”

“…For fluorescence labeling, 2h post-eclosion wings were fixed, stained and mounted as described [16].…”

“…This time we did not try to rescue miniature phenotype, but mimic it [16]. Such local expression of UAS-constructs permitted us to compare resulting phenotypes between two compartments (one of which served as the internal control) within one single wing.…”