Mutations in the RNAi machinery change the repertoire of hp-esiRNAs. (A) Size distribution and abundance of hp-esiRNAs in dicer-2 and r2d2 mutant fly heads compared to their heterozygous siblings or ago2414 mutants compared to Oregon R fly heads. (B) Decrease in hp-esiRNAs in dicer-2L811fsX, r2d21, and ago2414 mutant fly heads. (C) Change in full-length esi-2.1, esi-1.1, or esi-1.2 in dicer-2L811fsX, r2d21, and ago2414 mutant fly heads. (D) Relative abundance of hp-esiRNAs starting with each possible 5′ nucleotide as deduced from sequencing of small RNAs from the heads of ago2414 and r2d21 heterozygote or homozygote or Oregon R flies.