The sperm-oocyte switch in the C. elegans hermaphrodite is controlled through steady-state levels of the fem-3 mRNA

FEM-3 and MOG-6 expression in germlines. (A–C) In late L3 larvae, spermatids are not yet visible, but FEM-3 staining is present in the proximal part of the hermaphrodite germline. Sperm precursors are visible between the two arrowheads. Nuclear MOG-6 is present throughout the germline. The region between the two arrowheads is enlarged in D–F. (G–I) In L4 hermaphrodites, FEM-3 is visible throughout the sperm lineage, while MOG-6 is absent from secondary spermatocytes and spermatids. (1°) and (2°), primary and secondary spermatocytes, respectively; (Sp) spermatids. Bar, 10 μm.