We sequenced RNA16 from different cell lines and multiple subcellular fractions to develop an extensive RNA expression catalogue. Using a conservative threshold to identify regions of RNA activity, 62% of genomic bases are reproducibly represented in sequenced long (>200 nucleotides) RNA molecules or GENCODE exons. Of these bases, only 5.5% are explained by GENCODE exons. The majority of transcribed bases are within or overlapping annotated genes boundaries (i.e. intronic) and only31% of bases in sequenced transcripts were intergenic16.
