Circular RNA enrichment in platelets is a signature of transcriptome degradation

摘要: In platelets, splicing and translation occur in the absence of a nucleus. However, integrity stability mRNAs derived from megakaryocyte progenitor cells remain poorly quantified on transcriptome-wide level. As circular RNAs (circRNAs) are resistant to degradation by exonucleases, their abundance relative linear can be used as surrogate marker for mRNA transcription. Here we show that circRNAs enriched human platelets 17- 188-fold nucleated tissues 14- 26-fold samples digested with RNAse R selectively remove RNA. We compare RNAseq read depths inside outside provide silico evidence transcript circularity, exons within average 12.7 times identify 3162 genes significantly circRNAs, including some where all reads appear molecules. also confirm this is feature other anucleate through transcriptome sequencing mature erythrocytes, demonstrate not cultured megakaryocytes, decay more rapidly than platelet preparations. Collectively, these results suggest circulating have lost >90% occurs against backdrop highly degraded transcriptome. Finally, find transcripts previously classified products reverse transcriptase template switching both decay, countering recent suggestion up 50% rearranged artifacts.