Fig. 1. Dauer larva formation of unc-31(e169);sdf-14 double mutants. All the unc-31(e169);sdf-14 double mutants formed dauer larvae at high percentages at 25.5°C, whereas the unc-31(e169) single mutant formed dauer larvae only at 27°C and not at 25.5°C. sdf-14 mutants and wild-type animals did not form dauer larvae at either 25.5°C or 27°C. The results of the deletion mutant mrp-1(pk89) and unc-31(e169);mrp-1(pk89) are also shown, because sdf-14 was found to be allelic to mrp-1 in this study. The means of three plates are shown (33-199 animals/plate). The error bars indicate s.e.m. in all the figures of this paper.