The Mouse Mutant Resource

Exceptional mice, extraordinary insights

Mice bearing spontaneous, naturally occurring mutations are identified because they exhibit an apparent phenotype — the physical manifestation of a disease. This phenotype provides information about the function and biomedical relevance of the underlying mutant gene.

Mice harboring spontaneous mutations have long been a major source for animal models of human genetic disorders, but until recently the process of identifying causative mutations has been time-consuming and labor-intensive. Now, high-throughput DNA sequencing technologies have revolutionized the process of mutation detection, greatly reducing the time, effort and expense associated with disease-gene identification. Within the Mouse Mutant Resource at The Jackson Laboratory, we are using these technologies to study rare phenotypic deviant mice that arise spontaneously within the Laboratory's numerous large mouse colonies.

By identifying causative mutations and associated genes that underlie rare phenotypic anomalies, we are able to assign physiological functions to genes for which no role has previously been identified. In the process we also develop phenotypic deviant mice into animal models of human disease including rare human genetic diseases.


As the world's largest collection of novel strains of mice carrying spontaneous genetic mutations, the MMR has three key objectives:

  • To characterize — genetically, genomically and phenotypically — the spontaneous mutants that arise within our large breeding colonies;
  • To maintain and distribute mutant strains and associated information to the scientific community, and encourage use of these unique disease models;
  • To cryopreserve spontaneous mutation-bearing strains for future researchers.

Over 700 established mutant stocks are maintained in the Mouse Mutant Resource and 90-100 new mutations are at various stages of characterization. New mutant mice are made available to the scientific community once they have been characterized and described in journal publications.

Funding Sources

The Mouse Mutant Resource is supported by a National Institutes of Health grant, The Jackson Laboratory institutional funds, and fees from the sale and distribution of mice. Read more

Find out about strain availability and distribution

Leah Rae Donahue

"In mice with spontaneous mutations, you notice the clinical symptoms of a disease first, and you may discover a gene that no one suspected was involved with that disorder. Spontaneous mutations in the mouse offer the opportunity for true causative gene discovery."

~Leah Rae Donahue, Ph.D.
Director, Genetic Resource Science
The Jackson Laboratory


World's largest collection of spontaneous mutants

For more than 50 years, the Lab has maintained and expanded this unique resource of research models. 

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