Thrashing rates of L1 animals. The total number of body thrashes was counted during a 2 min period. A thrash was scored as a movement of the animal's body in either the dorsal or ventral direction. Error bars are ±SD. Values that are statistically different from wild type using the Student's t test (p ≪ 0.001) are marked with anasterisk. Results of experiments performed withunc-37(wd17) strains are denoted withgray shading.