Expression of FEM-3 in mutant germlines. (A–C) fbf-1 mutants produce both spermatids and oocytes. Staining of one adult gonadal arm with DAPI (A). GLD-1 is expressed in the cytoplasm of meiotic germ cell precursors, from the transition zone throughout pachytene. GLD-1 levels decrease rapidly in the diplotene region (B). FEM-3 is found in primary spermatocytes and later steps of spermatogenesis (C); white arrows indicate secondary spermatocytes. The region containing spermatids (Sp) is outlined. Open arrows point at oocyte nuclei. (D–F) Adult fem-3(q96) germlines are masculinized at 20°C. GLD-1 is expressed throughout the early meiotic prophase in a fully masculinized germline. FEM-3 expression is found between two white arrowheads; it corresponds to the spermatogenic region. Insets (anti-Fem-3, left, and DAPI, right) show expression of FEM-3 in the diplotene region and in primary spermatocytes. (G,H) Adult fbf-1 fbf-2 germlines are fully masculinized. The distal expression of FEM-3 indicates an early onset of spermatogenesis. (I,J) mog-1 mutants produce less sperm than fbf double mutants but also show early expression of FEM-3. Asterisks indicate the distal end of the germline, dashed lines indicate the mitosis-to-meiosis transition zone. Bar, 10 μm.
