# Stem cell and regeneration regulatory genes in planarians

> **NIH NIH R01** · WHITEHEAD INSTITUTE FOR BIOMEDICAL RES · 2020 · $377,910

## Abstract

Project Summary
Planarian flatworms are famous for their ability to rapidly regenerate new heads or even entire organisms from
a tiny fragment of the animal. Planarian regeneration involves a population of proliferative cells (neoblasts) that
include pluripotent adult stem cells (cNeoblasts) and that can produce every cell of the adult animal. Despite
centuries of fascination with regeneration, mechanistic explanations await elucidation. The broad, long-term
objectives of this proposal are to use planarians as a model system to identify and understand the molecular
mechanisms that regulate stem cells to promote regeneration. The specific aims are: 1) To determine the
mechanism of tissue-specific regeneration, 2) To determine how progenitors organize into a regenerated
structure, and 3) To identify in vivo regulatory mechanisms of stem cell fate specification. Stem cells and
regenerative biology are the subjects of recent and intense interest for regenerative medicince. In addition, the
misregulation of stem cells may be central to many types of cancer. A newly developed arsenal of tools for
molecular genetic study of stem cell biology in planarians now exists. For example, systematic gene
perturbation with RNA interference (RNAi) is possible and the planarian genome has been sequenced. Greater
than half of planarian genes have counterparts in the human genome; therefore, planarian studies should
identify conserved stem cell regulatory mechanisms. Aim #1 will determine the mechanisms by which a stem
cell response can bring about the specific regeneration of exactly those tissues that were missing. This is a
fundamental problem of wound repair and regeneration in most organisms, including humans. Aim #2 will
determine the mechanisms that lead regenerative progenitors to incorporate into the correct tissues at the
correct locations. We will utilize the study of planarian eye progenitors for this work. These eye progenitors
"home" to the exact location where eyes should form, and are incorporated into existing eyes. Aim #3 will
study the mechanisms of stem cell fate specification. Some processes must exist to regulate stem cell number
in planarians, and their choice to make more stem cells or to make differentiated cells. We will study how
contextual cues regulate this process by investigating candidate neoblast regulatory cells and by study of the
specialization of planarian stem cells into regenerative progenitors of the nervous system. Successful
completion of proposed aims will greatly advance our understanding of the mechanistic basis for regeneration
and advance planarians as a model system for the study of genes conserved in humans in stem cell and
regenerative biology, areas of great importance in human health.

## Key facts

- **NIH application ID:** 9965991
- **Project number:** 5R01GM080639-13
- **Recipient organization:** WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
- **Principal Investigator:** PETER REDDIEN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $377,910
- **Award type:** 5
- **Project period:** 2008-03-20 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9965991

## Citation

> US National Institutes of Health, RePORTER application 9965991, Stem cell and regeneration regulatory genes in planarians (5R01GM080639-13). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9965991. Licensed CC0.

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