RNAseq analysis of skeletal muscle transcriptomes from wild-type, FNIP1-knockout (FNIP1-KO) mice, and mice expressing FNIP1 only in skeletal muscle (FNIP1-TgKO).

This experiment was conducted to identify FNIP1-dependent mRNA transcripts alteration in skeletal muscle. Mouse FNIP1 was specifically overexpressed in skeletal muscle in FNIP1-transgenic (FNIP1-Tg) mice. FNIP1-Tg mice were crossed with FNIP1-knockout (FNIP1-KO) mice to generate FNIP1-TgKO mice expressing FNIP1 only in skeletal muscle but not in other tissues. The muscle glycolytic-to-oxidative transformation is determined, largely in part, at the level of gene expression. To gain insight into the FNIP1-dependent regulation of skeletal muscle energy metabolism, transcriptome analysis was performed by whole-genome gene expression profiling experiments in gastrocnemius (GC) muscle from both FNIP1-KO and FNIP1-TGKO mice. We were particularly interested in the subset of genes that were regulated only in the FNIP1-KO mice but not in FNIP1-TGKO mice. Gene ontology (GO) analysis revealed that the primary FNIP1-regulated genes were mitochondrial metabolic genes. A broad array of genes involved in mitochondria was regulated FNIP1-KO muscle in a FNIP1-dependent manner. Together, the transcriptional profiling results indicate that a significant subset of FNIP1 target genes, were those involved in mitochondrial function. Gastrocnemius muscle mRNA profiles of 8-week-old WT, FNIP1-KO and FNIP1-TGKO mice were generated by deep sequencing, in duplicate, using Illumina HiSeq 4000.