Myotubes derived from XaXa 609-hiPS cells restore normal dystrophin expression and nonskewed expression of the androgen receptor gene. (a) 409B2 iPSCs (normal), DMD-iPSCs (401-8, duplication of exons 45–50 of the dystrophin (DMD) gene), and manifesting carrier of DMD-iPS clones (609S-2, 609S-3, and 609S-4) were induced to differentiate into multinucleated myotubes. Normal iPS-derived myotubes expressed dystrophin. DMD-iPS-derived myotubes were negative for dystrophin. 609 iPSC-derived myotubes expressed dystrophin at comparable levels with wild-type myotubes. Scale bar: 500 μm. (b) RT-PCR analysis for dystrophin (DMD) and androgen receptor (AR) in myotubes derived from 409B2 iPSCs (normal), DMD-iPSCs (401-8), and manifesting carrier of DMD-iPSCs (609S-2, 609S-3, and 609S-4). Primer positions and directions for dystrophin transcripts are indicated by arrows. (c) Direct sequencing of CAG repeats of AR transcripts in myotubes derived from manifesting carrier of DMD-iPS clones (609S-2, 609S-3, and 609S-4). 609S-2 myotubes show allele 1(23 CAG repeats)—dominant expression. In 609S-3 and 609S-4 myotubes, two alleles (23 and 24 CAG repeats) are equally expressed.