Mutations define she-1 (spermless hermaphrodites), a novel F-box gene whose loss transforms C. briggsae XX hermaphrodites into self-sterile females that produce oocytes but no sperm; the gene is required for XX spermatogenesis.

she-1 acts in germline sex determination; mutants fail to produce FOG-3 protein, and she-1 arose by a recent gene duplication independent of the unrelated C. elegans F-box gene fog-2, demonstrating convergent recruitment of F-box genes to control hermaphrodite development.