Fig 1. An RNAi screen of putative de novo genes identifies CG13541 as a major contributor to Drosophila melanogaster male fertility.

A) All RNAi lines that showed at least partial knockdown of the target gene were screened in group fertility assays (see Materials and Methods). Relative fertility was calculated by dividing the average number of progeny produced per female mated to knockdown males by the average number of progeny produced per female mated to control males in a contemporaneous experiment. Relative fertility measurements lack error bars because each gene was tested in only 1–2 replicates. Knockdown of goddard was used as a positive control. B) A single-mating, single-pair fertility assay confirms the observed defect when males are knocked down for CG13541, as knockdown males showed significantly reduced fertility (control fertility (mean ± SEM): 109.0 ± 5.3; knockdown fertility: 0.2 ± 0.1; two-sample t-test assuming unequal variances, p = 5.6 x 10⁻¹³).