Activation of the EGFR/MAPK pathway drives transdifferentiation of quiescent niche cells to stem cells in the Drosophila testis niche

Elife. 2022 Apr 25:11:e70810. doi: 10.7554/eLife.70810.

Abstract

Adult stem cells are maintained in niches, specialized microenvironments that regulate their self-renewal and differentiation. In the adult Drosophila testis stem cell niche, somatic hub cells produce signals that regulate adjacent germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Hub cells are normally quiescent, but after complete genetic ablation of CySCs, they can proliferate and transdifferentiate into new CySCs. Here we find that Epidermal growth factor receptor (EGFR) signaling is upregulated in hub cells after CySC ablation and that the ability of testes to recover from ablation is inhibited by reduced EGFR signaling. In addition, activation of the EGFR pathway in hub cells is sufficient to induce their proliferation and transdifferentiation into CySCs. We propose that EGFR signaling, which is normally required in adult cyst cells, is actively inhibited in adult hub cells to maintain their fate but is repurposed to drive stem cell regeneration after CySC ablation.

Keywords: D. melanogaster; EGFR; niche cell; regeneration; regenerative medicine; stem cell; stem cells; testis; transdifferentiation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Transdifferentiation
  • Cysts* / metabolism
  • Drosophila / metabolism
  • Drosophila Proteins* / genetics
  • Drosophila Proteins* / metabolism
  • ErbB Receptors / metabolism
  • Male
  • Receptors, Invertebrate Peptide / genetics
  • Receptors, Invertebrate Peptide / metabolism
  • Stem Cells / physiology
  • Testis / metabolism
  • Tumor Microenvironment

Substances

  • Drosophila Proteins
  • Receptors, Invertebrate Peptide
  • Egfr protein, Drosophila
  • ErbB Receptors