Figure 5. RBFOX2₄₀ isoform driven transcriptome alterations in DM1 heart tissue.

(A) Overlap of differentially expressed (p<0.05, Wald test as described DESeq2; Log₂[Fold Change]>1, and TPM>4) with differentially spliced mRNAs (p<0.05, FDR<0.10 adjusted for multiple testing, Difference in Percent Spliced Index [ΔPSI]≥20%, and Junction Counts≥10) in cardiomyocytes isolated from hemizygous MHCrtTA, and TRE-RBFOX2₄₀; MHCrtTA bitransgenic mice after administration of 0.5g/kg Dox containing Chow for 3 days. (B) Position and relative enrichment of RBFOX-binding motif near RBFOX2₄₀ regulated cassette exons. (C) Breakup of 3144 RBFOX2₄₀ regulated splicing events in cardiomyocytes with or without RBFOX2₄₀ binding peaks and a GCAUG motif within those peaks from iCLIP data in mouse brain (Damianov et al., 2016). (D-E) Top 3 pentamers enriched within the binding peaks near RBFOX2₄₀ regulated exons with (D) or without (E) GCAUG motifs. Fractional enrichments of (D) UGUGU and (E) UUUUU sequences aligning at each nucleotide relative to the RBFOX2₄₀ crosslink site are also plotted. Overlap of (G) mRNA abundance, and (F) alternative splicing changes among cardiac transcriptomes of DM1 patients (Freyermuth et al., 2016), RBFOX2₄₀ overexpressing, CELF1 overexpressing, and Mbnl1^ΔE3/ΔE3 mice (Wang et al., 2015). (H) Directionality of mRNA abundance and alternative splicing changes in DM1 patient hearts and RBFOX2₄₀ overexpressing cardiomyocytes. (I) Distribution of changes in mRNA abundance and splicing events co-regulated in DM1 patient hearts and RBFOX2₄₀ overexpressing cardiomyocytes. (J) p-values of top Gene Ontology terms for alternatively spliced mRNAs in DM1 patient hearts (hypergeometric test; Benjamini method for multiple testing), and corresponding numbers of genes for each category that are similarly misspliced in the cardiomyocytes of RBFOX2₄₀ overexpressing, and hearts of CELF1 overexpressing, or Mbnl1^ΔE3/ΔE3 mice.