a, Examples of cryptic unstable transcripts (CUTs, orange data) upstream and antisense of DBF2,DRN1 and VAS1 promoters. The fold increase of CUT transcription in the rco1δ strain is marked. b, The transcription ratio (antisense/sense) in the rco1δ strain is plotted against the transcription ratio in the wild-type strain for each gene. c, A metagene analysis of well-expressed antisense transcription (n = 171, >1 read per bp).