Features of 26G siRNAs are conserved. (A) The proportions of conserved embryo and sperm class 26G siRNA target genes are shown for each species. (B) The percentages of C. elegans sperm class 26G siRNA target genes that contain an ortholog in C. briggsae, C. remanei, or C. brenneri, as well as the percentage of orthologous genes that produce 26G siRNAs in each species, are shown. (C) Box plots show the level of 22G siRNAs generated from embryo and sperm class 26G siRNA targets in adult hermaphrodites or females+males (purple), embryos (green), and adult males (gray). (D) Distribution of embryo and sperm class 26G siRNAs across each C. elegans or C. briggsae chromosome is overlaid in one plot. Position is relative to the total length of each chromosome. (E) Venn diagrams show the numbers of embryo and sperm class 26G siRNA targets and their overlap in each of the four species.