
An RPM was calculated based on short RNA-seq in each subcellular fraction—total chromatin fraction (CHR; red), total cytoplasmic fraction (CYT; yellow), total nucleoli fraction (NL; green), total nucleoplasmic fraction (NP; light blue), total nuclear fraction (NUC; purple), total whole-cell fraction (WC; pink)—and summed for all genes encoding for U1-RNA (A), U2-RNA (B), U3-RNA (C), U4-RNA (D), U5-RNA (E), U6 RNA (F), U6atac (G), and non–U-RNA snoRNAs (H).











