Figure 5.

RT–PCR expression analysis of novel and extended polycistronic snoRNA gene clusters. (A–C) RT–PCR of polycistronic snoRNA clusters. Primers were positioned in the genes indicated above the lanes (see also Supplementary Figures S1 and S2) and the expected RT–PCR product sizes are indicated below the lanes and are consistent with size markers. Some primers pairs were able to amplify more than one related precursor RNA (B). (A and D) Transcripts from single genes were amplified using primers to the 5′ and 3′ ends of the coding sequences.