OSM-6∷GFP overexpression in nphp-4 mutants results in a severe SynDyf phenotype. Compression of a 3D deconvoluted z stack of amphid ciliated neurons filled with DiI. Wild type (a) and kap-1 mutants (b) fill with DiI. In contrast, osm-3 animals (c) lacking distal segments of cilia fail to fill with DiI. Some but not all amphid neurons fill with DiI in nphp-4 single (d) and kap-1;nphp-4 double mutants (e). Panel f is a 2.5× view of wild-type and nphp-4 neuron cell bodies that filled with dye. There is slight variability in the neurons that fail to fill between individual animals. The OSM-6∷GFP transgene in the nphp-4 mutant background causes a SynDyf defect (j–l). The mnIs17 OSM-6∷GFP transgene does not interfere with dye filling in the wild type (g–i) or kap-1 or nphp-1 mutants (not depicted), nor does OSM-6∷GFP interfere with ciliogenesis in any published reports (Collet et al., 1998; Snow et al., 2004; Ou et al., 2005). Bars: (a) 20 μm; (f) 5 μm.