Differences of tsRNA expression profiles efficiently discriminate monozygotic twins in peripheral blood

Since monozygotic twins (MZTs) share extremely similar genomic DNA sequences, they cannot be distinguished by conventional forensic STR genotyping. The utilization of epigenetic factors in forensic application has gradually risen over the last few years. Epigenetic factors are characterized by dynamic changes and can be either inherited or accumulated as a result of acquired environmental influences. In this study, we analyzed the tsRNAs expression profiles in peripheral blood from four pairs of adult MZTs using PANDORA-sequencing (PANDORA-seq). Subsequently, the differential expressed tsRNAs (DEtsRNAs) were screened and confirmed by RT-qPCR and droplet digital PCR (ddPCR) in both adult and newborn MZTs. Additionally, the characteristics of the DEtsRNAs including longitudinal temporal stability, suitability for aged bloodstains and multigelation were evaluated. Overall design: To explore the potential of using epigenetic factors to distinguish monozygotic twins, we used PANDORA-seq to investigate the differential expression of tRNA-derived small RNA(tsRNA) in human peripheral blood of monozygotic twins.