Fig. 2. DAF-19 regulation of nph-1 and nph-4. RT-PCR analysis of (A) nph-1 and (B) nph-4 showed a marked decrease in expression of both genes in the daf-19(m86) mutant background compared to that seen in the daf-19(+) background. Synaptotagmin (snt-1) was used as a control for a neuronal gene whose expression is DAF-19 independent. (C) In vivo expression analysis of nph-1::CFP in daf-19(m86) mutant (left panels) and daf-19(+) (right panels) backgrounds. nph-1::CFP expression was greatly diminished in the daf-19(m86) background compared with daf-19(+). A similar reduction in expression is seen for che-13::DsRed2, a gene encoding an IFT protein that is known to be regulated by DAF-19. The merged image of nph-1::CFP and che-13::DsRed2 expression in the daf-19 (+) background shows that both of these genes are expressed in the same cells. (D) In vivo expression analysis in wild-type worms using the nph-4(mut)::DsRed transgene in which the X-box has been mutated. Mutation of the X-box results in the loss of nph-4 expression in the ciliated sensory neurons relative to the same nph-4 transgene with a wild-type X box (see Fig. 1B) or the IFT gene osm-5::CFP with wild-type X-box.