# Cytokinesis and RNA segregation in zebrafish development

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2021 · $306,034

## Abstract

Project Summary / Abstract
In many animal species, germ cell fate determination depends on the maternal inheritance of the germ plasm,
a specialized cytoplasm composed of ribonucleoparticles (RNPs) and enriched in cytoskeletal elements. Germ
plasm RNPs are typically inherited as particles within the egg, which during early embryogenesis become
aggregated into large masses. These become segregated into primordial germ cells (PGCs), where they are
thought to promote the initiation of the germ cell transcriptional program. In zebrafish, as in a number of other
vertebrate species, gathering and segregation of germ plasm RNPs is coupled to cell division. Zebrafish germ
plasm has been shown to be required and sufficient for germ cell induction in this organism. We have
previously delineated specific steps during cell division that result in germ plasm RNP recruitment to the
furrows for the first several cycles, with subsequent compaction at the furrow distal ends. These steps entail a
gradual increase in germ plasm RNP aggregation and result in the stabilization of four large germ plasm
masses. These masses are inherited by PGCs, to eventually disperse through the cytoplasm during PGC
specification. Our overarching hypothesis is that germ plasm RNP aggregation is mediated by adaptations
of the cellular machinery, relying on the interaction between a dynamic, excitable cortex and fluid
phase-like properties of RNPs and associated intrinsically disordered proteins (IDPs). In Aim 1, we will
address how the regulation of an excitable actomyosin network mediates germ plasm RNP movement and
aggregation, and will study the function of factors components of the Chromosomal Passenger Complex (CPC)
in cytoskeletal network dynamics and germ plasm RNP anchoring. In Aim 2, we will study the behavior of
segregating germ plasm RNPs as ordered supramolecular structures at the furrows, as well as the role in germ
plasm segregation of the previously uncharacterized IDP Bucky ball 2-like. The germ cell fate shares
characteristics with pluripotency and cancer, and our studies will provide new knowledge applicable not only to
reproduction but also cell reprogramming and cancer biology. Understanding of membrane-less
compartmentalization through fluid phase behavior will provide additional fundamental insights relevant to
human biology and disease.

## Key facts

- **NIH application ID:** 10116404
- **Project number:** 5R01GM065303-15
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** FRANCISCO J PELEGRI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $306,034
- **Award type:** 5
- **Project period:** 2002-03-01 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10116404

## Citation

> US National Institutes of Health, RePORTER application 10116404, Cytokinesis and RNA segregation in zebrafish development (5R01GM065303-15). Retrieved via AI Analytics 2026-06-14 from https://api.ai-analytics.org/grant/nih/10116404. Licensed CC0.

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