Fig. 8. The NPH-4 protein is required for proper localization of NPH-1 to the transition zone. To explore the possibility that the NPH proteins function as part of the same complex, we analyzed the localization of the NPH proteins in the reciprocal mutant background. (A) Compared to wild-type controls, NPH-4::YFP localization was not altered by loss of nph-1. (B) In contrast, NPH-1::CFP was not detected at the transition zone in nph-4 mutants indicating that NPH-4 is required for NPH-1 localization. (C) The localization of NPH-1::CFP to the transition zone was restored by crossing the strain back to wild-type worms.