The landscape of RNA polymerase II transcription initiation in C. elegans reveals a novel regulatory architecture

It has recently been shown that RNA Polymerase II transcription is far more extensive than previously thought, much of it not associated with protein-coding genes. To investigate this phenomenon, we determined the genome-wide landscape of RNA Polymerase II transcription initiation and elongation in C. elegans. We identify 73,500 distinct clusters of transcription initiation and find that initiation is often bidirectional. Strikingly, the majority of initiation events occur in regions with enhancer-like chromatin signatures. We also assign transcription initiation sites to 7691 protein coding genes, the majority previously unknown because of trans-splicing. Through mapping RNA PolII initiation (short capped RNAs) and elongation (long capped RNAs), we provide identification of transcription start sites.