# Drying, Storing, and Reanimating Egg Germinal Vesicles to Preserve Fertility

> **NIH NIH R01** · SMITHSONIAN INSTITUTION · 2021 · $89,029

## Abstract

Project Summary
 The ability to preserve the female gamete (oocyte) is critical for women wanting to retain fertility
before cancer therapy, treat infertility or delay reproduction. However, oocyte freezing is complex
because of the cell’s large size, significant water content and fragile cellular skeleton. Storing this cell
and other biomaterials at ultra-low temperature also is costly, which complicates the USA-wide need for
more biorepositories to address human health issues. Our research is advancing a transformative way of
preserving the maternal genome by compacting, drying, storing at supra-zero temperatures and
reanimating the oocyte’s nucleus (germinal vesicle, GV) rather than the entire cell. We study the
domestic cat, a model that shares many physiological mechanisms and genomic similarities with the
human. In the recent years, we have demonstrated that: 1) good quality oocytes can be reconstructed
with competent GVs from early stage follicles that are delivered into high quality, recipient cytoplasts; 2)
fundamental epigenetic marks and key proteins of the GV are controlled and sustained within the
nucleus, thereby confirming the value of preserving isolated nuclei; and 3) desiccated cat GVs retain
viability for weeks, with the remaining challenge being to maintain a low and stable moisture content to
prevent degradations during storage. Findings to date have guided us to three priorities: 1) desiccation
of the GV to an intermediate moisture level combined with biostabilizing agents; 2) a precisely formulated
rehydration protocol; and 3) production of embryos and viable offspring with unaltered epigenetic
patterns. The overall hypotheses are: 1) the maternal genome and associated nuclear factors are
securely preserved at room temperature by desiccating the GV at a higher (more accommodating)
moisture content when combined with biostabilizing agents; 2) key GV components are fully
recovered by an appropriate rehydration process after storage; and 3) these enhancements
promote GV survival and reanimation in a recipient cytoplast as well as the ability of the
reconstructed oocyte to mature, be fertilized and successfully develop into a normal embryo in
vitro/in vivo. Likelihood of achieving the project’s priorities is high given our recent results and our
access to novel, advanced tools, including new controlled environmental chambers for the desiccation
and Tubular Perfusion Systems for rehydration as well as computational transcriptomics/epigenomics to
validate the viability of resulting embryos. Besides providing an improved understanding of the resilience
of the oocyte’s nucleus, end products will inform on the practicality and safety of GV storage in
reproductive health care, management of biomedical models and alternative options in building lower-
cost repositories.

## Key facts

- **NIH application ID:** 10464007
- **Project number:** 3R01OD023139-05S2
- **Recipient organization:** SMITHSONIAN INSTITUTION
- **Principal Investigator:** Pierre Comizzoli
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $89,029
- **Award type:** 3
- **Project period:** 2017-08-15 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10464007

## Citation

> US National Institutes of Health, RePORTER application 10464007, Drying, Storing, and Reanimating Egg Germinal Vesicles to Preserve Fertility (3R01OD023139-05S2). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10464007. Licensed CC0.

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