# Epitope Tagging by Prime Editing in Zebrafish

> **NIH NIH R21** · TEMPLE UNIV OF THE COMMONWEALTH · 2021 · $237,750

## Abstract

Project Summary
Recently published search-and-replace genome editing tools utilize the Cas9 nickase to make a
single strand break at the target site, followed by introduction of the desired edit by reverse
transcriptase using the 3' end of a specifically modified guide RNA (pegRNA) as the template.
These tools, named Prime Editors, appear far superior to current state-of-the-art methodologies
such as homology directed repair using oligonucleotide templates. It is important to test if this
superior performance will reproduce in other model systems including the zebrafish. We propose to
use Prime Editors to carry out epitope tagging of several zebrafish genes which play important roles
in a variety of biological processes from early embryo patterning to axon guidance and
regeneration. Over the course of this work we will determine which Prime Editor has optimal activity
in zebrafish, test several important variables of pegRNA design such as the length of the Primer
Binding Site, and produce transgenic lines maternally expressing Prime Editor(s), thus facilitating
broad application of this method by the research community.

## Key facts

- **NIH application ID:** 10303928
- **Project number:** 1R21HD103982-01A1
- **Recipient organization:** TEMPLE UNIV OF THE COMMONWEALTH
- **Principal Investigator:** Darius Balciunas
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $237,750
- **Award type:** 1
- **Project period:** 2021-08-01 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10303928

## Citation

> US National Institutes of Health, RePORTER application 10303928, Epitope Tagging by Prime Editing in Zebrafish (1R21HD103982-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10303928. Licensed CC0.

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