The Running Mice

Researchers of the University of Pennsylvania and his colleagues genetically engineered mice to lack the IL-15Rα gene, and the modified mice ran six times farther than normal mice each night. Previous studies had suggested that IL-15Rα is important for muscle strength. The genetically-modified mice seemed to lack fast-twitch muscles - muscles that allow more precise movements but tire faster - and to have only slow-twitch muscles - which have more endurance but do not allow fine movements. This could explain why the mice did not tire, but the cause of their behavioral changing was not clear. Why they wanted to run for hours every night? The scientists argue that human resistance to fatigue could be affected by this same gene and that this could be a possible target for human diseases.
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Missing Gene Helps Mice Run for Hours - ScienceNOW