Fig. 1

SRSF3 and SRSF7 exert opposite effects on 3′UTR length. a Scatter plots of percentage of distal poly(A) site usage index (PDUI) in Srsf3 (left) and Srsf7 (right) KD and control (Ctrl) P19 cells. Significant changes highlighted in blue and orange, respectively (adjusted P value ≤ 0.1, |ΔPDUI| ≥ 0.05). b Density plot of differences in ΔPDUI for significant changes shown in a. Dashed lines indicate median. c, d Venn diagram (c) and UpSet plot (d) of genes with significant changes in 3′UTR-APA after Srsf3 or Srsf7 KD. Numbers of target genes and direction regulated by either SR protein are given below. e Semiquantitative 3′RACE-PCR of selected transcripts affected by Srsf3 or Srsf7 KD. Proximal (pPAS; pink) or distal (dPAS; green) PAS usage as well as the positions of primers are indicated next to the gels. f Scheme of the MACE-seq library preparation. RT, reverse transcription. g Pie chart of protein-coding genes harboring one, two, three, or more PASs identified by MACE-seq. h Stacked bar charts show the proportion of PASs associated with a given CSE in gene categories as in c. Analyzed PASs included single (sPASs), pPASs, dPASs, and other PASs (oPASs)