Production of proliferative Follicle Cells (FCs) and quiescent Escort Cells (ECs) by Follicle Stem Cells (FSCs) in adult Drosophila ovaries is regulated by niche signals from anterior (Cap Cells, ECs) and posterior (polar FCs) sources. Here we show that ECs, FSCs and FCs develop from common pupal precursors, with different fates acquired by progressive separation of cells along the AP axis and a graded decline in anterior cell proliferation. ECs, FSCs and most FCs derive from Intermingled Cell (IC) precursors interspersed with germline cells. Precursors also accumulate posterior to ICs before engulfing a naked germline cyst projected out of the germarium to form the first egg chamber and posterior polar FC signaling center. Thus, stem and niche cells develop in appropriate numbers and spatial organization through regulated proliferative expansion together with progressive establishment of spatial signaling cues that guide adult cell behavior, rather than through rigid early specification events.
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files are provided for all graphical data.
- Daniel Kalderon
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Claude Desplan, New York University, United States
- Received: April 24, 2021
- Accepted: September 29, 2021
- Accepted Manuscript published: September 30, 2021 (version 1)
© 2021, Reilein et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.