circTAIL-seq, a targeted method for deep analysis of RNA 3′ tails, reveals transcript-specific differences by multiple metrics

(A) Schematic illustrating steps of circTAIL-seq. Thick gray line indicates a coding region of a generic mRNA that is not amplified in the process. The generic RNAs 5′ UTR and 3′ UTRs are represented in violet and red, respectively. “AAUAAA” represents all potential nonencoded tails on the ends of the RNAs. The orange region on PCR products is the bar code introduced during PCR. (B) Informatics workflow for circTAIL-seq data analysis.