# Somatic stem cells in the Drosophila ovary

> **NIH NIH R01** · COLUMBIA UNIV NEW YORK MORNINGSIDE · 2021 · $362,241

## Abstract

Project Summary
 Adult stem cells supporting different tissues can meet the dual demands of lifelong persistence and
continued production of daughter cells that differentiate through a variety of strategies, which have
presumably evolved to suit demand. Highly proliferative stem cells that support continuously renewing
epithelia in skin and intestines are especially important targets of investigation to understand how a large
replicative burden is distributed, how mutations initiate pre-cancerous amplification, and how stem cells
might be used for regenerative therapies. Somatic follicle stem cells (FSCs) in the Drosophila ovary provide
an exceptional opportunity to examine highly proliferative epithelial stem cell organization, dynamics and
regulation in detail.
 This proposal builds on extensive prior use of genetic methods for lineage tracing and direct imaging
of stem cells and their progeny to construct a sophisticated and much revised picture of the location,
dynamics and immediate products of a community of FSCs in their niche. The arrangement of FSCs has
remarkable similarities to mammalian intestinal stem cells. In both cases, a group of about sixteen stem
cells is maintained by a population asymmetry mechanism where stem cell division and differentiation are
not coupled. Importantly, this leads inevitably to stabilization and amplification of faster-proliferating mutant
stem cell lineages. Both types of stem cell also exhibit heterogeneous behaviors along the major
developmental axis but individual stem cells also can exchange positions (“dynamic heterogeneity”). FSCs
in different locations directly produce two different cell types. For FSCs, genetic interrogation of signaling
pathways has defined three principal, graded external signals that regulate FSC behavior.
 These insights will be pursued further to build an integrated picture of FSC behavior and how it is
regulated by niche signals. One objective is to define how spatially graded FSC proliferation is imposed by
graded JAK-STAT and Wnt pathway signaling. A second objective is to define how these same signals
specify the location and alternative differentiation outcomes for individual FSCs and the community as a
whole. A third objective is to understand how FSCs and associated niche cells develop prior to adulthood
under the guidance of emerging patterns of external signals. The insights gained will provide information
about how stem cells co-operate and compete within a community, how niche cells communicate with stem
cells, a better understanding of how some cancers can initiate and how stem cell behavior might be
manipulated for therapeutic benefit.

## Key facts

- **NIH application ID:** 10135978
- **Project number:** 5R01GM079351-12
- **Recipient organization:** COLUMBIA UNIV NEW YORK MORNINGSIDE
- **Principal Investigator:** DANIEL D KALDERON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $362,241
- **Award type:** 5
- **Project period:** 2009-09-30 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10135978

## Citation

> US National Institutes of Health, RePORTER application 10135978, Somatic stem cells in the Drosophila ovary (5R01GM079351-12). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10135978. Licensed CC0.

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