Profile: C57BL/6J
JAX® NOTES Issue 438, July 1989
Over the years, The Jackson Laboratory has raised and distributed countless C57BL/6Js. But has anyone wondered why this particular mouse, first bred in 1921 by Jackson Laboratory founder C.C. Little, has been so popular or acquired its name?
Research associate Priscilla Lane calls the C57BL/6J "the mouse of choice" because not only is it a good breeder and long lived but also has a low suspectibility to tumors and few unfavorable characterizations.
During the 1950's and 1960's staff scientist emeritus Elizabeth Russell placed many pigment mutations including those with anemias onto the C57BL/6J background. Later Richard Sidman of Harvard and a member of the board of scientific overseers here along with his coauthors used the C57BL/6J mouse as the mode for the Atlas of the Mouse Brain and Spinal Cord. As a result of this study, neurological mutations arising spontaneously on this background were kept on it while many others were placed on it.
Because of its high alcohol preference, this strain has been used by some researchers to examine the mode of inheritance and the effects of alcohol on mice of different ages.
Blacks are also one of the oldest inbred strains. While at cold Spring Harbor in 1921, Little started a new "family of mice" descended from mice received from Miss Abby Lathrop, a mouse supplier from Granby, Massachusetts.
Sometime after 1900 Lathrop began raising small animals, including a waltzing mouse, as pets. Although initially she planned only to raise two or three hundred, she began receiving orders for hundreds of mice from research institutions, and her business expanded. Many of the mice used, for example, in the coat color experiments conducted while Little was an undergraduate at Harvard came from Lathrop.
To start this strain, Little bred female mouse number 57 to male mouse number 52. The result was a black mouse soon designated C57 black. Based on the earlier coding used by Little such as d, b, a for dilute, brown and nonagouti and c for albinos, Lane theorizes that the upper case "C" may have stood for the nonalbino allele (the normal full color allele). Today, however, all strain names are expected to adhere to standard nomenclature rules.
But the C57BL/6J mice are not only an old and venerable strain, they are also very lucky. During the May 10, 1989 fire, these mice were in a section of Morrell Park that was behind a fire wall. This JAX strain was not affected by the fire, and consequently stocks of this mouse are at prefire levels. "Fortunately for researchers the popular C57BL/6J strain is available in large enough quantities to supply both scientists who have traditionally used this mouse and those who may now elect to use it," said Barbara Witham, manager of service and distribution.
