The Black 6 mouse strain is the most commonly used lab mouse in the United States, and its highly inbred nature has led scientists to believe that closely related strains are just that, harboring very few genetic differences. But a study published in Science suggested that not only do mice of Black 6 substrains differ at the level of their DNA, but that those genetic variations can translate into some fairly significant behavioral differences.
Read the full, original story: Common Lab Mice Differ