The laboratory mouse or lab mouse is a small mammal of the order Rodentia which is bred and used for scientific research or feeder for certain pets. Laboratory mice are usually of the species Mus musculus. They are the most commonly used mammalian research model and are used for research in genetics, physiology, psychology, medicine, and other scientific disciplines. Mice belong to the Euarchontoglires clade, which includes humans. This close relationship, the associated high homology with humans, their ease of maintenance and handling, and their high reproduction rate, make mice particularly suitable models for human-oriented research. The laboratory mouse genome has been sequenced and many mouse genes have human homologs.

The history of mice in science.

The first record of animals being used as models for human anatomy and physiology dates back some 2,400 years to ancient Greece. Humans understood quite early on that by studying animals, we could learn much about ourselves. When these findings were documented they were conveyed to other countries via trade routes and animal modeling soon became a research tool of both European and Arab physicians.

However, it wasn’t until the Renaissance that animal modeling contributed to a true paradigm shift in our understanding of human physiology. The circulatory system was studied by William Harvey in many species. His comparisons of the different physiologies of eels and other fish, chicks, and pigeons, contributed to an accurate and detailed description of the physiology in humans. Harvey was particularly careful in his selection of model species, in order to exploit the different properties of each animal.

The first mouse models.

Scientists often turn to mice as their first choice if they need to study a mammalian model. Mice share around 80% of our genes, they are close to us on the evolutionary tree and are physiologically similar to humans. They are small and have a short lifespan, breed rapidly, and do well in captivity, and their genetic and behavioral traits have been studied for over 100 years now.

By the 1700s, many varieties of mice were domesticated as pets in China and Japan, and Europeans imported favorites and bred them with local mice. This breeding led to the creation of progenitors of modern laboratory mice as hybrids among M. m. domesticus, M. m. musculus, and other subspecies. In Victorian England, ‘fancy’ mice were prized and traded, and a National Mouse Club was founded in 1895.