Fig. 1. The exc-5 gene is required for formation of excretory canals. (A) Diagram showing the position of excretory canals. The apical surface is shown in pink, the basolateral in blue. (B–E) The excretory canal (arrowheads) is visualized using sek-1::GFP expression. The photos show posterior excretory canals. Cysts are shown by arrows. Vu, vulva. (B) unc-119(e2498) with sek-1:GFP and pDP#MM016B (unc-119) (Maduro and Pilgrim, 1995). (C) exc-5(km508) with sek-1::GFP and pRF4 (rol-6d). (D) exc-5(rh232) with sek-1::GFP and pRF4 (rol-6d). (E) exc-5(rh232); mig-2(gm38) with sek-1::GFP and pRF4. The right panel shows the excretory canal at high magnification. The cyst (arrow) is much smaller than that in exc-5(rh232) single mutants. Scale bars, 20 µm.