Fig. 1.

Muscle weakness and exercise intolerance in TR4^{−/ −} mice. A, Determination of muscle strength by rotarod test. Four pairs of TR4^−/− vs. TR4^+/+ mice were tested, and the mean latency for TR4^−/− mice to fall off the rod was significantly shorter than that for TR4^+/+ mice. **, P < 0.01. B, Determination of muscle strength by whole-animal muscle strength and fatigability test. Three pairs of TR4^−/− vs. TR4^+/+ mice were used, and the percentage of passes over 15 trials of the test in a 3-min period in TR4^{−/ −} mice was significantly reduced. **, P < 0.01. KO, Knockout; WT, wild type.