Published on December 22, 2013 at 1:20 PM
The C57BL/6J "J" mouse is the gold-standard strain for most research involving the mouse. For example, the reference sequence for the mouse genome, as well as most behavioral and physiological experiments, are based on the "J" strain. However, the International Knockout Mouse Consortium will be shifting emphasis to the "N" strain since they have created 17,000 embryonic stem cell lines with gene mutations that originate from the "N" strain. Thus, identifying genetic differences between these two mouse strains is important, Dr. Takahashi said.
"Although mouse geneticists pay close attention to the specific strains of mice that they use, it has not been generally appreciated that sublines of the same strain of mouse might differ so profoundly. Thus, a 'C57BL/6' mouse might appear to be the same, but in fact there are many, many sublines of this laboratory mouse, and it is important to know which exact one you are using. Since the knockout mouse project has produced so many mutations (17,000) derived from the 'N' strain, it will be even more important to keep in mind that not all C57BL/6 mice are the same."
Source: UT Southwestern Medical Center