Rngo is required for ring canal growth and plasma membrane integrity in the female germline. (a–c) A control germline clone (glc, a) and rngo^GE3956 germline clones (b and c) stained for F-actin (red) and Hts-RC (blue). Note the abnormally large ring canal (b, arrows) and the fusion of at least two nurse cells with the oocyte (c). Insets to the right of a and c show higher magnifications of the oocyte nucleus (red arrows) and an adjacent nurse cell nucleus in the boxed regions. Note the elongated shape of the oocyte nucleus in c. (d and e) A control germline clone (d) and rngo^GE3956 germline clone (e) stained for Filamin (red) and Kel (blue). Note the rudimentary ring canals (arrowheads) and the diffuse cytosolic localization of Kel in e. (f and g) A control germline clone (f) and rngo^GE3956 germline clone (g) stained for PY epitopes (blue). Rudimentary ring canals in g are marked by arrowheads. DNA was stained with DAPI (turquoise). Germline clones are marked by an absence of GFP (green) expression. Note that for imaging of Hts-RC, Kel, Filamin, and PY in rngo^GE3956 germline clones, a much higher gain of the photomultiplier was used than in the respective wild-type controls. Egg chambers are at stages 7 and 8. Anterior is to the left. (h and i) Quantification of outer ring canal diameter of ring canals connecting nurse cells (h) and a nurse cell with the oocyte (i). (j) Quantification of the fusion between nurse cells and the oocyte. In h, n = 40 for stages 3–7, and n = 19 for stage 8. In i, n = 16 for stages 3–7, and n = 6 for stage 8. The statistical significance of the differences was calculated with the Student’s t test; ***, P < 0.01. In j, n = 15 for all stages. Error bars represent SDs from three independent experiments. Bars: 20 µm; (insets) 10 µm.