Anatomy of the anterior face of the stage 10B oocyte. (A–A″″′) Stage 10B egg chamber marked with nuclear GFP (green), phalloidin fluorescence (purple), and α-cadherin staining (red) identifies oocyte, NCs, NCN, follicle cells, border cells, and RCs, but phalloidin or cadherin staining is absent at the anterior face of the oocyte at the site of entering NC nucleus. Frontal optical sections, orientation anterior up (A and A″–A″″′) and transverse section created from a 3D projection of confocal optical sections (A′). (B–F) 3D projection images of stage 10B egg chambers with channel at oocyte anterior face, rotated for partially axial orientations, marked with membrane-tethered GFP (green) and α-lamin (red; B), α-lamin (red) and phalloidin fluorescence (C), phalloidin fluorescence (D), and Dpp:Cherry (red) and α-cadherin (green; E, E′, and F). Arrow indicates channel (B). (G) EM images of successive sections of a stage 10B oocyte showing continuous plasma membrane across the anterior oocyte face (1 and 6) and channel through which a NC nucleus enters (2–5). Orientation anterior up (B, C, and G). Cartoons depict sectioned egg chamber. Scale bars: 50 µm (bar in A for A–D and F; bar in A′ for A′–A″″′, E, and E′); 20 µm (G).