tRF-mRNA chimeras are abundant in AGO1 CLASH data. (A) Numbers of CLASH reads that started with a perfect match to a miRNA, tRF-3, tRF-5 or tRF-1 and deemed to not be pre-miRNA, tRNA or a RNA in Ref-Seq. (B) Numbers of miRNA, tRF-5, tRF-3 or tRF-1 chimeras with mRNAs. (C) Alignments of the mRNA portion of the 45 most abundant reads for the tRF-3003a-HIST2H2AA4 interaction and the tRF-3034a-RPL35A interaction to the corresponding mRNA. The tRF-3 portion of the reads is depicted in dashed blue while the mRNA fragment is depicted in red. CLASH, cross-linking, ligation, and sequencing of hybrids.