1. Ecdysone regulates the Drosophila imaginal disc epithelial barrier, determining the length of regeneration checkpoint delay.
- Author
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DaCrema D, Bhandari R, Karanja F, Yano R, and Halme A
- Subjects
- Animals, Drosophila melanogaster genetics, Drosophila melanogaster growth & development, Ecdysone genetics, Gene Expression Regulation, Developmental, Imaginal Discs metabolism, Larva genetics, Larva growth & development, Neurons metabolism, Signal Transduction genetics, Drosophila Proteins genetics, Imaginal Discs growth & development, Intercellular Signaling Peptides and Proteins genetics, Receptors, G-Protein-Coupled genetics, Regeneration genetics
- Abstract
Regeneration of Drosophila imaginal discs, larval precursors to adult tissues, activates a regeneration checkpoint that coordinates regenerative growth with developmental progression. This regeneration checkpoint results from the release of the relaxin-family peptide Dilp8 from regenerating imaginal tissues. Secreted Dilp8 protein is detected within the imaginal disc lumen, in which it is separated from its receptor target Lgr3, which is expressed in the brain and prothoracic gland, by the disc epithelial barrier. Here, we demonstrate that following damage the imaginal disc epithelial barrier limits Dilp8 signaling and the duration of regeneration checkpoint delay. We also find that the barrier becomes increasingly impermeable to the transepithelial diffusion of labeled dextran during the second half of the third instar. This change in barrier permeability is driven by the steroid hormone ecdysone and correlates with changes in localization of Coracle, a component of the septate junctions that is required for the late-larval impermeable epithelial barrier. Based on these observations, we propose that the imaginal disc epithelial barrier regulates the duration of the regenerative checkpoint, providing a mechanism by which tissue function can signal the completion of regeneration., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)
- Published
- 2021
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