NFM-1, which may be the upstream regulator of WTS-1, is involved in the maintenance of intestinal membrane polarity. (A) Defective GFP::ACT-5 localization in nfm-1 mutant. nfm-1 mutant initially established normal apical polarity, but gradually lost the polarized distribution of GFP::ACT-5 at the apical domain. Lower graph: quantified results. Worms were categorically scored and quantified as done in Figure 2B. (B) WTS-1 subcellular localization in nfm-1(ok754)/+ and nfm-1(ok754) intestines. (A and B) hT2[qIS48], which has a pharyngeal GFP signal, was used as a dominant balancer for nfm-1. The GFP signal was used as a marker to identify control heterozygotes. Bar, 10 µm.