Fig. 5: Candidate-based RNAi screen identified that GTF-2F2, GTF-2H2C, MDT-8, and RPB-5 are required for piRNA production.

a, b A candidate-based RNAi screen identified transcription factors required for piRNA focus formation of UAD-2 and TAF-12. These candidates include factors of the RNA Pol II, the Mediator complex, the P-TEFb complex and general transcription factors TFIIA, -B, -D, -E, -F, and -H. n > 30. Source data are provided as a Source Data file. c Fluorescence images of representative meiotic germ cells of the indicated animals expressing UAD-2::GFP and AID::RPB-5, AID::GTF-2F2, AID::GTF-2H2C, or AID::MDT-8 (with or without auxin treatment). Scale bar, 5 μm. n = 4 independently imaged worms over three independent experiments with similar results. d The relative abundance of total mature piRNAs (n = 28,219) in young adult hermaphrodites expressing UAD-2::GFP and AID::RPB-5, AID::GTF-2F2, AID::GTF-2H2C, or AID::MDT-8 (with or without auxin treatment). The central horizontal line within the box represents the median piRNA abundance. Each box displays the interquartile range of the data (between the 25th and 75th percentile). Unpaired Wilcoxon test was used to derive p values. ****p value  <  2.2 × 10⁻¹⁶. e Meiotic germ cells of animals that express mCherry::PRDE-1 and GFP::GTF-2H2C, GFP::MDT-8, GFP::GTF-2F2, or GFP::RPB-5. GTF-2H2C and MDT-8 aggregate at piRNA foci and colocalize with PRDE-1. The white arrows indicate piRNA foci, the purple arrow indicates an unidentified focus of GFP::GTF-2H2C in germ cells. Scale bar, 5 μm. n = 6 independently imaged worms over three independent experiments with similar results. f Yeast two-hybrid assay to probe for protein-protein interactions between UAD-2, TAF-12, MDT-8, GTF-2F2, GTF-2H2C, and RPB-5. On nonselective medium (left) all constructs allow growth equally, under selection (right) only strains expressing proteins that interact can grow.