Germplasm Preservation of Animal Models for Biomedical Research

Figure 1. Cryopreservation tank and vials. Image courtesy of the U.S. Department of Agriculture.

Animal models are essential to understanding human diseases and in maintaining human health through development of diagnostic approaches and therapeutic interventions. Large numbers of animal models of human disease are being generated at an unprecedented rate due to rapidly evolving technological advancements, such as gene-editing techniques. However, this rapid increase in essential animal models also is creating challenges in how to maintain these critical resources in reliable and cost-effective ways, as long-term preservation of such animal models will be key in ensuring efficiency, reproducibility, and transparency in biomedical research.

Figure 2. Rat pronuclear injection. Image courtesy of Dr. Elizabeth Bryda, University of Missouri.

One solution to these challenges is to use germplasm preservation methods for long-term storage of valuable and evolving animal models. The Office of Research Infrastructure Programs (ORIP) has supported research projects on developing efficient germplasm preservation methods, including cryopreservation methods, for diverse animal models, such as mouse, rat, and fish. These projects are developing new methods or improving existing methods to preserve embryos, eggs, or sperms for a variety of animal model species. Development of effective germplasm preservation technologies would serve the entire biomedical research community and further promote and conserve the value of animal models for human diseases.

Figure 3. Drosophila embryos in liquid nitrogen. Image courtesy of Dr. John Bischof, University of Minnesota.

As part of the effort to respond to the needs and challenges identified by the research community and outlined in the reports of two workshops—“Cryopreservation of Aquatic Biomedical Models” organized by ORIP and “Cryopreservation of Drosophila Strains” organized by ORIP, in collaboration with the National Institute of General Medical Sciences and the National Institute of Neurological Disorders and Stroke—ORIP has published several funding opportunity announcements, including PAR-19-176, titled “Methods Development for Cryogenic or Other Long-term Preservation and Revival of Drosophila and Zebrafish Genetic Stocks (R21 Clinical Trial Not Allowed).”

Other recent ORIP activities in this area include the following:

• ORIP Commentary in Nature Lab Animal: “Nonhuman primate models for SARS-CoV-2 research: Cryopreservation as a means to maintain critical models and enhance the genetic diversity of colonies”
• ORIP Fact Sheet: Cryopreservation: Research and Resources
• ORIP Research Highlight: “Safeguarding the Valuable Genetic Stock Collections of Public Repositories”

Examples of projects funded by ORIP include—

Drosophila cryopreservation and rewarming for long-term storage
R21 OD028758
John C. Bischof
University of Minnesota
Related Publication: Nature Communications

Development of a novel method for cryopreservation of Drosophila melanogaster
R24 OD028444
Daryl Gohl
University of Minnesota

Safeguarding Genetic Resources of Aquatic Biomedical Models
R24 OD028443
Terrence R. Tiersch
Louisiana State University

An Ultra-fast Cooling Device for Vitrification and Cryopreservation of Cells and Tissues
R44 OD020163
Xu Han
CryoCrate LLC

Drying, Storing, and Reanimating Egg Germinal Vesicles to Preserve Fertility
R01 OD023139
Pierre Comizzoli
Smithsonian Institute