Figure 1

Evidence for piRNA-guided cleavage of target mRNAs. (A) Sequence overlap between 5′-RACE-identified mRNA fragments and predicted targeting piRNAs in the 3′-UTR of Psma8 transcripts. The upper part shows the location of Psma8 mRNA fragments. The piRNA data are from normal mouse testes (GSM822760, Miwi^+/+), and the mRNA fragment data are from normal (GSM822765, Miwi^+/−) or catalytic mutant (GSM822766, Miwi^−/ADH) mice¹⁷. Blue dots: mRNA fragments at the single-nucleotide resolution; green dots: piRNAs with extensive base paring with the mRNA; red dots: mismatches; yellow dots: G-U wobble pairs; short lines: gaps. (B) The distribution of matched piRNA reads near the mRNA fragment in A. (C) Comparison of Psma8 mRNA levels (log₂ transferred followed by subtracting the mean of the control values) in Miwi slicer activity-deficient mutant (Miwi^−/ADH) mouse testes relative to Miwi^+/− controls (data from GEO: GSE32180¹⁷). (D) mRNA fragment reads and targeting piRNAs at 3′-UTR of BC026590 similarly illustrated as in A. (E) The distribution of matched piRNA reads near the mRNA fragment as in B. (F) Expression difference of BC026590 in Miwi catalytic (Miwi^−/ADH) mutants relative to Miwi^+/− controls as described in C.