Genetically engineered mice serve as valuable models of human disease, contributing to major medical breakthroughs. Often, biomedical researchers must develop unique genetically modified strains of mice for experimentation, a costly and time-consuming process. Now, more researchers in fields from immunology to cancer may be able to save time and money by acquiring genetic material from a repository of previously engineered strains.
Immunologist Dr. Bruce Beutler of the University of Texas Southwestern Medical Center contributed sperm from genetically modified mouse strains that have more than 175,000 genetic mutations to the Mutant Mouse Resource and Research Centers (MMRRC), a repository supported by the National Institutes of Health (NIH). Dr. Beutler’s team created the mouse strains while working toward identifying genes that regulate immunity and inflammation in a project supported by the National Institute of Allergy and Infectious Diseases, part of the NIH.
The contribution from Dr. Beutler’s laboratory increases tenfold the number of induced mouse mutations publicly available in sperm or egg cells. Through in vitro fertilization, the MMRRC can use cryogenically frozen sperm in its repository to produce mice with desired genetic modifications and transfer the mice to researchers.
The UT Southwestern team rapidly produced this large number of genetically modified mouse strains through a technique known as ENU mutagenesis. In this process, scientists expose mice to N-ethyl-N-nitrosourea (ENU), a chemical that stimulates genetic mutations in the stem cells that produce sperm. Although Dr. Beutler’s team screened the mice to look specifically for effects on immune regulation, genetic mutations frequently influence more than one cellular or bodily process, and thus this resource would be of interest to a wide range of researchers. For example, researchers studying genetic regulation of muscle repair or neurological communication could use these genetically modified mouse models for their own studies. Information on each mutation the team created is available in a publicly available internet database called Mutagenetix under “Incidental Mutations.”
Kentner Singleton, Ph.D., program officer in the Basic Immunology Branch of NIAID’s Division of Allergy, Immunology and Transplantation, is available to comment.