Transcriptional noise and the fidelity of initiation by RNA polymerase II.

Eukaryotes transcribe much of their genomes, but little is known about the fidelity of transcriptional initiation by RNA polymerase II in vivo. I suggest that 90% of Pol II initiation events in yeast represent transcriptional noise, and that the specificity of initiation is comparable to that of DNA-binding proteins and other biological processes. This emphasizes the need to develop criteria that distinguish transcriptional noise from transcription with a biological function.