# Genetically enabling Hydra oligactis for comparative studies in development, regeneration and aging.

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2024 · $241,500

## Abstract

PROJECT SUMMARY
The small freshwater cnidarian Hydra has played a crucial role in several scientific breakthroughs, most
notably being the first animal where regeneration was discovered in 1744. Over the years, different Hydra
species contributed to fundamental findings, but Hydra vulgaris has become the standard "Hydra model" in
modern molecular research. With a chromosome-level genome assembly and tools to test gene function, H.
vulgaris is a prime model for developmental and regenerative biology but is also an emerging model in various
fields including neuroscience and microbiome research. In contrast, Hydra oligactis, another Hydra species,
remains underutilized despite its biologically relevant distinct features. Unlike H. vulgaris, H. oligactis
exhibits deficiencies in regenerating its aboral end and undergoes senescence and death upon gamete
production. The sharp contrasts between these closely related species offer a unique comparative platform for
exploring molecular mechanisms in regeneration and aging.
Despite being behind in tools and resources, H. oligactis can be reliably cultured, making it a promising
candidate for functional studies. Completion of the proposed aims will bridge the gap between the two species:
 1. Build Genomic and Transcriptomic Resources: Develop a chromosome-scale genome assembly with
 gene regulatory annotations, and a single-cell expression atlas for H. oligactis, paralleling the resources
 available for H. vulgaris.
 2. Implement Transgenesis and siRNA Knockdown: Establish transgenesis in H. oligactis and create
 transgenic lines that express fluorescent proteins in specific lineages. These lines will enable the
 optimization of gene knockdown through siRNA electroporation.
 3. Develop CRISPR Gene Editing: Utilize the inducible egg production in H. oligactis to troubleshoot
 CRISPR-Cas9 mediated gene editing. The immediate goal is to tag the endogenous EF1-alpha gene, a
 strategy that will inform future gene editing attempts in both H. oligactis and H. vulgaris.
The completion of these aims will equip H. oligactis with tools and resources comparable to H. vulgaris,
enabling functional studies and comparative analyses. This comparative approach holds potential implications
for various scientific fields, including developmental and regenerative biology, aging, neuroscience,
microbiome research, and biophysics. This project is therefore highly responsive to the FOA (PAR-21-167),
which calls for the development and improvement of animal models that are relevant to multiple NIH
Institutes.

## Key facts

- **NIH application ID:** 10997108
- **Project number:** 1R21OD037741-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Celina Juliano
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $241,500
- **Award type:** 1
- **Project period:** 2024-07-15 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10997108

## Citation

> US National Institutes of Health, RePORTER application 10997108, Genetically enabling Hydra oligactis for comparative studies in development, regeneration and aging. (1R21OD037741-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/10997108. Licensed CC0.

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