RNA was isolated from XX primary myoblast and 24-h-differentiated myotube cells using Tripure (Roche) followed by the RNeasy Micro kit (Qiagen). Samples with RNA Integrity numbers of ≥9 were used for sequencing. RNA-Seq was performed in two batches: (A) two wild type myoblasts, three wild type myotubes and two ΔICR/ΔICR myotube samples were sequenced at the NIH Intramural Sequencing Center using Illumina HiSeq2000 sequencers; and (B) two wild type myoblasts, two wild type myotubes and two ΔICR/ΔICR myoblasts were sequenced at the NICHD Molecular Genomics Core using an ABI SOLiD 5500xl sequencer. Ribosomal RNA was depleted from 1 to 5 μg total RNA using the RiboZero Gold kit (Illumina). Library preparation for the Illumina HiSeq2000 was performed using the TruSeq RNA Sample Prep V2 kit (Illumina). Pooled barcoded libraries were sequenced to generate paired-end 101 bp reads and raw data was aligned to mouse genome version mm9 using Tophat2 (33 (link)). For the ABI SOLiD sequencing, libraries were prepared using the SOLiD Whole Transcriptome Analysis kit (Thermo Fisher Scientific). Pooled barcoded libraries were sequenced to generate paired-end 35 × 75 bp reads and colorspace XSQ data was aligned to mouse genome version mm9 using Lifescope software (Thermo Fisher Scientific).