Hedgehog signalling is required for cell survival in Drosophila wing pouch cells

Juan Lu,Jie Shen,Dan Wang

doi:10.1038/s41598-017-10550-4

Abstract

An appropriate balance between cell survival and cell death is essential for correct pattern formation in the animal tissues and organs. Previous studies have shown that the short-range signalling molecule Hedgehog (Hh) is required for cell proliferation and pattern formation in the Drosophila central wing discs. Signal transduction by one of the Hh targets, the morphogen Decapentaplegic (Dpp), is required for not only cell proliferation, but also cell survival in the pouch cells. However, Hh function in cell survival and cell death has not been revealed. Here, we found that loss of Hh signal activity induces considerable Caspase-dependent cell death in the wing pouch cells, and this process was independent of both Dpp signalling and Jun-N-terminal kinase (JNK) signalling. Loss of Hh induced activation of the pro-apoptotic gene hid and inhibition of diap1. Therefore, we identified an important role of Hh signalling in cell survival during Drosophila wing development.

Highlights

The balance between cell death and cell survival is essential for the development of animal tissues and organs
The Cubitus interruptus (Ci)[act] enters the nucleus and induces target genes expression, including engrailed, ptc, Collier, and dpp. These target genes are activated in a Hh-concentration dependent manner: The cells close to the AP compartment boundary receive the highest level of Hh and induce the ptc and en; the cells away from the AP compartment boundary will receive the lowest level of Hh and induce the expression of col; the cells between these two type of cells receive the moderate level of Hh and induce the expression of dpp49–52. ptc acting as the target gene of Hh signaling inhibits Smo expression in the absence of Hh46
The Hh transportation from the posterior to the anterior was blocked by expressing ttvRNAi in the dpp-Gal[4] domain, obvious apoptosis was consistently observed in the central wing discs (Fig. 1C)

Summary

Introduction

The balance between cell death and cell survival is essential for the development of animal tissues and organs. We found that Hh signaling plays an important role in the cell survival in the Drosophila wing pouch. The Hh transportation from the posterior to the anterior was blocked by expressing ttvRNAi in the dpp-Gal[4] domain, obvious apoptosis was consistently observed in the central wing discs (Fig. 1C).

Results

Conclusion