Extended Data Fig. 3. Ribosomes directly bind to pachytene piRNA precursors.

a, Schematic of Ribo-seq library construction. b, Northern hybridization of a piRNA from a pachytene piRNA precursor, 7-qD1-16444. Total RNAs from equal amounts of testis lysates treated with or without RNaseA&T1 were resolved by electrophoresis and detected by northern hybridization. The intensity of probe signals has been confirmed to be linear with respect to the amount of RNA (r > 0.99). c, Length histogram of RPFs from mRNA protein coding regions. d, Fragment length analysis plot of total RPF reads per transcript and FLOSS relative to the nuclear coding sequence average from wild-type testes. Fragment Length Organization Similarity Score (FLOSS) was computed as previously described²³. For different raw read counts, to detect extremely large FLOSS values, outlier cutoffs were calculated using Tukey’s fences method and smoothed using LOESS regression. The purple curve shows the smoothed cutoff line. piRNAs were downsampled to match the read number of RPFs from piRNA precursors before calculating FLOSS. Statistical Source Data are provided in Source Data Extended Data Figure 3. Unprocessed blots are provided in Source Data Extended Data Figure 3.