The noncoding region of Nop60B (Uhg6) oscillates with peak expression at ZT6. (A) The Nop60B.a transcript includes six protein-coding exons and seven noncoding exons ([solid black bars] exons) separated by a large intron (thin blue line). Smaller introns separating exons 7–13 are excised from Nop60B.a transcripts and processed to form mature snoRNAs and snmRNAs. (Black boxes) Mature ncRNAs expressed at detectable levels; (gray boxes) undetectable ncRNAs. (Red histograms) The depth of sequencing coverage in this region at ZT0, ZT6 (peak), ZT12, and ZT18 (trough). (B) Expression levels of Nop60B's coding exons show weak or nonexistent circadian oscillations while the noncoding exons (C) and (the median-normalized) ncRNAs they encode (D) oscillate with peak expression at ZT6.
