Peptidergic signaling from clock neurons regulates reproductive dormancy in Drosophila melanogaster

PLoS Genet. 2019 Jun 13;15(6):e1008158. doi: 10.1371/journal.pgen.1008158. eCollection 2019 Jun.

Abstract

With the approach of winter, many insects switch to an alternative protective developmental program called diapause. Drosophila melanogaster females overwinter as adults by inducing a reproductive arrest that is characterized by inhibition of ovarian development at previtellogenic stages. The insulin producing cells (IPCs) are key regulators of this process, since they produce and release insulin-like peptides that act as diapause-antagonizing hormones. Here we show that in D. melanogaster two neuropeptides, Pigment Dispersing Factor (PDF) and short Neuropeptide F (sNPF) inhibit reproductive arrest, likely through modulation of the IPCs. In particular, genetic manipulations of the PDF-expressing neurons, which include the sNPF-producing small ventral Lateral Neurons (s-LNvs), modulated the levels of reproductive dormancy, suggesting the involvement of both neuropeptides. We expressed a genetically encoded cAMP sensor in the IPCs and challenged brain explants with synthetic PDF and sNPF. Bath applications of both neuropeptides increased cAMP levels in the IPCs, even more so when they were applied together, suggesting a synergistic effect. Bath application of sNPF additionally increased Ca2+ levels in the IPCs. Our results indicate that PDF and sNPF inhibit reproductive dormancy by maintaining the IPCs in an active state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified / genetics
  • Brain / metabolism
  • CLOCK Proteins / genetics*
  • Circadian Rhythm / genetics
  • Diapause / genetics
  • Diapause / physiology
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / growth & development
  • Gene Expression Regulation / genetics
  • Insulin / genetics
  • Neurons / metabolism
  • Neuropeptides / genetics*
  • Reproduction / genetics*
  • Signal Transduction / genetics

Substances

  • Clk protein, Drosophila
  • Drosophila Proteins
  • Insulin
  • Neuropeptides
  • neuropeptide F, Drosophila
  • pdf protein, Drosophila
  • diapause hormone
  • CLOCK Proteins

Grants and funding

This work was funded by INsecTIME (FP7- PEOPLE-2012-ITN, grant no. 316790) to RC, CHF, CPK and ER. CHF and CHL were additionally supported by the CRC 1047 “Insect timing” (project-A1). RC was also supported by the National Research Council of Italy grant (EPIGEN Progetto Bandiera Epigenomica – subproject 4). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.