Alternative splicing of <i>MBNL1</i> and <i>MBNL2</i> during myogenic differentiation in vitro in presence and absence of an expanded (CTG)2600 repeat.

(A, B) Gene structures of MBNL1 and MBNL2, adapted from [1,11]. Boxes represent exons, numbered 1–10, connected by horizontal lines, the introns. Exon lengths are indicated in base pairs. Primers for RT-PCR are shown as red arrows. (C, D) The main alternative splice modes for MBNL1 and MBNL2 identified in this study and the molecular weights of the corresponding protein products, adapted from [1,11]. (E, F) Summary of RNA-seq data of the most prominent alternative splice modes of MBNL1 and MBNL2 in proliferating myoblasts with and without (CTG)2600 repeat (averaged data of four cell lines for each condition). Numerals indicate the percentage of reads spanning an upstream exon to a downstream exon. (G, H) Representative QIAxcel images of RT-PCR analyses of the exon 4 to exon 10/9 region in MBNL1 and MBNL2, respectively, in proliferating myoblasts (-2) and at day 0 and 5 of myogenic differentiation. (I, J) Quantification of the RT-PCR data shown in (G, H).