Comments & suggestions  should be directed to Visit my website THE LABORATORY MOUSE The laboratory mouse was derived from the common house mouse, Mus musculus.   Development of the laboratory mouse began with pet fanciers who bred mice for their unique coat colors.  These fancy mice then became subjects for research due to interest in the mechanisms of inheritance of these coat colors.  W. E. Castle began studying the genetics of coat color in mice in the early 1900's.  Inbred strains of mice were later developed by Clarence Cook Little in 1909. As mice became more widely used in research, some individuals began breeding them for sale. Today commercial breeders such as Charles River and Harlan provide most of these animals for the research community.  The Jackson Laboratory (Jax), a nonprofit research and training institution, is one of the major suppliers of mice for research in the United States and throughout the world.  There are approximately 1750 strains, including inbred strains, hybrids, spontaneous mutants, induced mutants, chromosomal aberrations, and wild derived strains currently available from Jax.  Because of the constant discovery of new mutations and the production of knockout and transgenic mice, the number of mouse stocks and strains currently available continues to increase.  To give some idea of the importance of rodents in research, during 1998 17.2 million mice and 5.5 million rats were used at 1200 U.S. research institutions. compared to a total of 1.2 million animals of other species.  Mice, and rats together constitute approximately 90% of the total animals used for all research purposes. There are many advantages of mice as research animals.  Their genetic characterization, the large number of strains available, and the large list of catalogued mutant genes provide animals suited for a number of different areas of research.  Mice are easy to care for and handle, and are relatively inexpensive compared to other species.  A high reproductive performance with a large litter size and a short gestation means that many generations can be produced in a relatively short period of time (one million descendants after 425 days).  The disadvantages of mice as research animals include their small size, which limits the procedures that may be performed as well as the sample volume size that can be obtained from an individual animal.  To overcome the latter limitation, samples from several animals may be pooled for research analysis and statistical significance. The use of the mouse as a research animal has resulted in many scientific advancements.  Much of our early understanding of the immune system was derived from studying the mouse.  The use of the mouse continues to be an important part of various research endeavors including aging, embryology, cancer induction, pharmacological and toxicological testing, and infectious diseases research.  Transgenic and knockout mice have become important tools for investigating the relationship of genetic make-up to disease states as well as elucidating pathways of normal mammalian development. Behavior Housing Diet & Nutrition Animal ID Acclimatization Special Anatomic and Physiological Features Reproduction Pheromones Restraint & Handling Injection Sites Blood Collection Miscellaneous Techniques Pain & Distress Euthanasia Occupational Helath Concerns