(A) Screening assay for mutants with reduced male precedence, showing outcomes for mating failure, mating by wild-type males, and mating by males with less-competitive sperm. (B) me69 males have decreased precedence in the screen assay. Males were mated to spe-8(hc53); dpy-4 hermaphrodites, and offspring were scored as Dumpy (self) or non-Dumpy (cross) progeny. (C) me69 and gk1149 mutant hermaphrodites have normal self fertility. Total self progeny of unmated hermaphrodites were counted. Error bars, 95% confidence intervals; p > 0.05 (Student's t test). (D) Mutants for comp-1 have defects in male precedence. Males were mated to dpy-4 hermaphrodites, and offspring were scored as Dumpy (self) or non-Dumpy (cross). (E) Schematic of the F37E3.3 gene showing the kinase-like domain (green) predicted by the Conserved Domains Database (Marchler-Bauer et al., 2011) and the locations of the me69 and gk1149 alleles. Boxes, exons; black, coding regions; gray, 5′ and 3′UTRs. (F) Expression of the F37E3.3 gene in sperm rescues the comp-1 male precedence defect. Male precedence was assayed for comp-1(gk1149); jnSi168[Ppeel::comp-1] and control strains as in Figure 1D. (B, D, F) Each point represents the result of an individual cross; lines indicate medians. ***, p < 0.001; **, p < 0.01; ns, not significant (Kolmogorov–Smirnov test; all comparisons are to wild-type). In addition to the genotypes shown, all males were homozygous (B, C, F) or heterozygous (D) for him-5(ok1896), and control strains in (F) harbored oxSi221.