DJ-1 KO mice show motor and mitochondrial dysfunction. (A) Rotorod test of control (solid) and DJ-1 KO (dashed) animals of different ages, showing a significant (P < 0.01) difference by 15 months (mean ± SD, n = 6–10 animals per time point). (B, Upper) ATP levels (moles/mg) in hindlimb skeletal muscle (a mixture of soleus and gastrocnemius muscle) of control (white) and DJ-1 null (gray) mice (mean ± SEM, n = 6 animals) (two-tailed t test, P = 0.017 between 14-month control and KO samples). (Lower) ATP levels from brain extracts (mean ± SEM, n = 6 animals).