Effect of gtl-1 and gon-2 loss-of-function mutations on intestinal Ca²⁺ oscillation rhythmicity. (A) Calcium oscillations in single intestines isolated from wild-type, GTL-1 mutant, GON-2 mutant, and double mutant worms. (B) Calcium oscillation rhythmicity in wild-type and mutant worm intestines. Rhythmicity is quantified as coefficient of variance. Values are means ± SEM (n = 6–10). *, P < 0.05; **, P < 0.001, compared with wild-type worms. All worm strains were grown at 25°C.