C57BL6MouseModelInformationSheetCharlesRiver-.PDFVIP

research models C57BL/6 Mice NOMENCLATURE: C57BL/6NCrl Strain Origin Developed by C.C. Little in 1921 from a mating of Miss Abbie Lathrop’s stock that also gave rise to strains C57BR and C57L. Strains 6 and 10 separated about 1937. To The Jackson Laboratory from Hall in 1948. To NIH in 1951 from The Jackson Laboratory at F32. To Charles River in 1974 from NIH. Coat Color: Black Produced: North America, Europe and Japan C57BL/6 Mice NOMENCLATURE: C57BL/6NCrl Genetic Management of C57BL/6 Mouse Colony Inbred strains are defined as animals produced by a minimum of 20 generations of brother-sister mating, traceable to a single founding pair. Charles River uses our International Genetic Standardization (IGS) program coupled with a pyramid mating system designed to maintain authenticity and the highest possible levels of genetic uniformity. The pyramid mating system (see Figure 1) ensures that our C57BL/6 colonies are genetically identical within each strain (i.e., fundamentally free of genetic differences that could increase variation in experimental results). In this system, the foundation colony serves as the genetic and health standard and provides breeders for the top level of the pyramid in every barrier room. This top level, the nucleus colony, is composed of a relatively small number of pedigreed brother-sister mating pairs that produce breeders for the next level of the pyramid, in addition to replenishing itself. In larger colonies, the next level is called the expansion colony, and it provides breeders to the production colony, which in turn produces the anima