Misplaced nuclei in fli-1(ky535) are partially surrounded by germ line plasma membrane. Shown are transmission electron microscopy cross-sections of gonads from wild-type and fli-1(ky535). (A) A cross-section through the meiotic pachytene zone of wild-type. The nuclei are arranged at the cortex (the arrowhead indicates a nucleus) and are partially surrounded by germ line plasma membrane, forming the "T" structure (arrow). (B) Cross section through the meiotic pachytene zone of a fli-1(ky535) mutant. Misplaced nuclei are apparent (arrow), and misplaced nuclei are surrounded by germ line plasma membrane in a manner similar to nuclei at the cortex (internal "T" structure-like membrane organization is indicated by the arrow). (C and D) Magnification of regions in the dashed boxes in (A) and (B). The arrowheads indicate nuclei and the arrows indicate germ line plasma membrane. Scale bars = 2 μm for all micrographs.