# Discovery of germline genes and regulatory networks in planarians

> **NIH NIH R15** · WRIGHT STATE UNIVERSITY · 2020 · $163,167

## Abstract

SUMMARY
Proper development of gametes is crucial for the continuation of sexually reproducing species. To succeed,
germline stem cells that populate the gonads must complete a long developmental process that yields highly
differentiated cells: the sperm and egg. These can come together to form a totipotent zygote capable of
developing into an individual. Thus far, genetic screens in mice, flies, and nematodes, have identified
numerous genes required development of the germline. However, voids remain to be filled in our
understanding of the genetic mechanisms that secure the production of functional gametes. To fill some of
these voids, the proposed line of research will explore a new avenue for discovery of genes involved in
germline development. The planarian flatworm Schmidtea mediterranea is an increasingly popular organism
for stem cell research, which holds great promise as a model for reproductive biology studies. Planarians have
an unmatched ability to completely regenerate their entire reproductive system, including germ cells,
throughout their lifetime. This allows experimental analysis of the entire process of gametogenesis without
being confined to a specific developmental window, or limited by potential secondary effects on
embryogenesis. Also relevant is the fact that planarians specify their germline through inductive signals that
originate from the soma, which is also true of mammals (but not of flies or nematodes). Experiments performed
as part of this proposal are expected to reveal conserved pathways that control germ cell development by: 1)
Elucidating the structure and function of cytoplasmic ribonucleoprotein granules that regulate spermatogenesis
intrinsically; 2) Uncovering the identity and fate of mRNA targets of these granules through association with the
highly-conserved Cytoplasmic Polyadenylation Element Binding Protein-2; and 3) Identifying components of
genetic pathways involved in non-cell autonomous (i.e. extrinsic) regulation of germline development. Due to
availability of optimized protocols for assessing distribution of gene expression in planarians, ease of
maintenance and induction of systemic knockdown, as well as availability of molecular markers for virtually
every tissue, the expression and function of dozens of genes can be determined during the award period by
research performed in large part by undergraduate students. Completion of this project is important because it
will reveal conserved processes involved in development of functional gametes. Additionally, this work will
expose hundreds of undergraduate students to meritorious research, and strengthen the research environment
at Wright State University, which are specific goals of the AREA program.

## Key facts

- **NIH application ID:** 9964225
- **Project number:** 2R15HD082754-02A1
- **Recipient organization:** WRIGHT STATE UNIVERSITY
- **Principal Investigator:** Labib Rouhana
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $163,167
- **Award type:** 2
- **Project period:** 2014-09-25 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9964225

## Citation

> US National Institutes of Health, RePORTER application 9964225, Discovery of germline genes and regulatory networks in planarians (2R15HD082754-02A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9964225. Licensed CC0.

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