# Adaptive protein evolution of the Drosophila germline stem cell gene bag of marbles

> **NIH NIH R01** · CORNELL UNIVERSITY · 2020 · $322,164

## Abstract

Project Summary
Animals, including humans, contain a small number of cells in their gonads called germline stem
cells (GSCs). These cells are essential for making sperm or eggs throughout the lifetime of the
animal. The decision for a dividing stem cell to renew as a stem cell or to differentiate, and the
regulation of early divisions during GSC are some of the most critical decisions in development.
Studies in the fruit fly, Drosophila melanogaster, have identified many of the key genes involved
in the cellular signaling for GSC maintenance and differentiation. Several of the key GSC
regulatory genes are rapidly evolving under adaptive evolution in two closely related species of
Drosophila (D. melanogaster and its sibling species D. simulans) but not in several additional
closely related species. The key “switch” gene for GSC differentiation, bag of marbles (bam)
has accumulated a highly significant excess of amino-acid changes between these two closely
related species (13%). This proposal focuses on identifying the functional consequences of
these changes and gaining insight into possible evolutionary forces driving these changes,
including interactions with the endosymbiotic bacteria Wolbachia. This knowledge is essential
for understanding how GSCs are regulated during normal development and how their
misregulation due to mutation and interaction with germline parasites can lead to infertility,
germline cancers, and reproductive isolation. Our proposed studies provide a framework with
which to test the functional consequences and evolutionary forces driving these evolutionary
changes in genes controlling stem cell fate decisions in Drosophila as well as in other
organisms, including humans.

## Key facts

- **NIH application ID:** 9928301
- **Project number:** 5R01GM095793-08
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** CHARLES F AQUADRO
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $322,164
- **Award type:** 5
- **Project period:** 2011-08-01 → 2021-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9928301

## Citation

> US National Institutes of Health, RePORTER application 9928301, Adaptive protein evolution of the Drosophila germline stem cell gene bag of marbles (5R01GM095793-08). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9928301. Licensed CC0.

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