# Somatic stem cells in the Drosophila ovary

> **NIH NIH R01** · COLUMBIA UNIV NEW YORK MORNINGSIDE · 2024 · $376,727

## Abstract

Project Summary
 Adult stem cells must meet the dual demands of lifelong persistence and continued production of
derivatives, as needed. Highly proliferative stem cells that support continuously renewing epithelia, as in
human skin and intestines, are especially important medical targets of investigation to understand how
mutations initiate pre-cancerous amplification, and how stem cells might be used for regenerative therapies.
Recent investigations of Follicle Stem Cells (FSCs) in the Drosophila ovary have illuminated a detailed
picture of their behavior, including direct differentiation to two different cell types, locally graded proliferation,
independent regulation of division and differentiation, and remarkable similarities to the organization of
mammalian intestinal stem cells. FSCs now provide an exceptional opportunity to exploit Drosophila
genetics, accessibility to comprehensive high-resolution fixed and live imaging, and a relatively simple
system to examine the organization, dynamics and regulation of highly proliferative adult stem cells in detail.
 FSCs function as a community in which individual stem cells behave stochastically and compete for
niche space. FSCs directly differentiate to a quiescent cell type at the anterior face of the FSC domain and
to proliferative Follicle Cells (FCs) at the posterior face. FSCs also divide more rapidly in posterior regions
and dynamically exchange locations. FSC behaviors are substantially guided by the strength of two graded
signaling pathways (Wnt and JAK-STAT) of opposite polarity. Potential effectors of these signals will be
sought, in part, through single-cell expression profiling. Their function in regulating FSC proliferation and
differentiation will be tested using established lineage analyses of genetic variants that yield quantitative
measures of location, cell division and differentiation responses. These will be supplemented by new
methods that examine cell cycle reporters in fixed and live samples, and by developing “GRASP” reporters
of surface interactions between marked FSCs and neighboring FCs, ECM and germline cysts to explore the
mechanism of FSC conversion to FCs.
 Adult stem cell function depends on prior development of appropriate numbers and organization of
stem cells and supporting niche cells. Recent insights show that FSCs and niche cells share common
precursors, with fates acquired gradually through progressive refinement of cell locations. Potential signals
and mediators that guide specification of the first FCs will be investigated to provide complementary insights
to those gained from studying FC formation in adults, where the morphological changes and signaling
environment differ significantly.
 Genetic manipulations affecting division rates, differentiation and signaling profiles of the whole FSC
community will be used to expose community regulative mechanisms that can modify FSC behavior,
responses or the signaling environment in order to maintain stem cell numb...

## Key facts

- **NIH application ID:** 10919794
- **Project number:** 5R01GM079351-14
- **Recipient organization:** COLUMBIA UNIV NEW YORK MORNINGSIDE
- **Principal Investigator:** DANIEL D KALDERON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $376,727
- **Award type:** 5
- **Project period:** 2009-09-30 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10919794

## Citation

> US National Institutes of Health, RePORTER application 10919794, Somatic stem cells in the Drosophila ovary (5R01GM079351-14). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10919794. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*