Transcriptional Maps of 10 Human Chromosomes at 5-Nucleotide Resolution

TLDR

The study mapped transcription sites of polyadenylated and nonpolyadenylated RNAs on ten human chromosomes at 5‑bp resolution across eight cell lines. The analysis revealed that most transcriptional output consists of unannotated, nonpolyadenylated RNAs, with 19.4% polyadenylated, 43.7% nonpolyadenylated, and 36.9% bimorphic, and that half of all transcribed sequences are nuclear‑restricted, forming interlaced networks that impact genotype‑phenotype interpretation, gene regulation, and gene definition.

Abstract

Sites of transcription of polyadenylated and nonpolyadenylated RNAs for 10 human chromosomes were mapped at 5–base pair resolution in eight cell lines. Unannotated, nonpolyadenylated transcripts comprise the major proportion of the transcriptional output of the human genome. Of all transcribed sequences, 19.4, 43.7, and 36.9% were observed to be polyadenylated, nonpolyadenylated, and bimorphic, respectively. Half of all transcribed sequences are found only in the nucleus and for the most part are unannotated. Overall, the transcribed portions of the human genome are predominantly composed of interlaced networks of both poly A+ and poly A– annotated transcripts and unannotated transcripts of unknown function. This organization has important implications for interpreting genotype-phenotype associations, regulation of gene expression, and the definition of a gene.