Fig. (3) MBNL1/CUGBP1 target gene expression in immortalized DM1 cell lines. (A) RT-PCR analysis to detect splicing defects in MBNL1/CUGBP1 target genes using primers in flanking exons: TNNT2 exon 5 (E5) inclusion, INSR exon 11 (E11) exclusion and SERCA1 exon 22 (E22) exclusion in DM1 cells (in comparison to WT cells). Equal levels of cDNA template were confirmed by amplification of the GAPDH housekeeping gene. (B) Western blot analysis for CLCN1 skeletal muscle-specific chloride channel expression in immortalized WT and DM1 cell lines. β-actin protein expression was used as a loading control.