STANDARD_NAME CHEMELLO_SOLEUS_VS_EDL_MYOFIBERS_DN SYSTEMATIC_NAME M3004 COLLECTION C2:CGP MSIGDB_URL https://www.gsea-msigdb.org/gsea/msigdb/human/geneset/CHEMELLO_SOLEUS_VS_EDL_MYOFIBERS_DN NAMESPACE Operon_V1.1 DESCRIPTION_BRIEF Genes down-regulated in type 2B (EDL) vs type 1 (soleus) myofibers. DESCRIPTION_FULL BACKGROUND: Skeletal muscle is a complex, versatile tissue composed of a variety of functionally diverse fiber types. Although the biochemical, structural and functional properties of myofibers have been the subject of intense investigation for the last decades, understanding molecular processes regulating fiber type diversity is still complicated by the heterogeneity of cell types present in the whole muscle organ. METHODOLOGY/PRINCIPAL FINDINGS: We have produced a first catalogue of genes expressed in mouse slow-oxidative (type 1) and fast-glycolytic (type 2B) fibers through transcriptome analysis at the single fiber level (microgenomics). Individual fibers were obtained from murine soleus and EDL muscles and initially classified by myosin heavy chain isoform content. Gene expression profiling on high density DNA oligonucleotide microarrays showed that both qualitative and quantitative improvements were achieved, compared to results with standard muscle homogenate. First, myofiber profiles were virtually free from non-muscle transcriptional activity. Second, thousands of muscle-specific genes were identified, leading to a better definition of gene signatures in the two fiber types as well as the detection of metabolic and signaling pathways that are differentially activated in specific fiber types. Several regulatory proteins showed preferential expression in slow myofibers. Discriminant analysis revealed novel genes that could be useful for fiber type functional classification. CONCLUSIONS/SIGNIFICANCE: As gene expression analyses at the single fiber level significantly increased the resolution power, this innovative approach would allow a better understanding of the adaptive transcriptomic transitions occurring in myofibers under physiological and pathological conditions. PMID 21364935 GEOID GSE23244 AUTHORS Chemello F,Bean C,Cancellara P,Laveder P,Reggiani C,Lanfranchi G CONTRIBUTOR Emmanuelle Fouilloux-Meugnier CONTRIBUTOR_ORG CarMeN Laboratory EXACT_SOURCE Dataset 1S: Fig4: MyHC1 < MyHC 2B FILTERED_BY_SIMILARITY EXTERNAL_NAMES_FOR_SIMILAR_TERMS EXTERNAL_DETAILS_URL SOURCE_MEMBERS M000088_01,M000364_01,M000684_01,M000959_01,M000962_01,M001311_01,M001670_01,M002107_01,M002331_01,M002642_01,M002819_01,M003013_01,M003795_01,M005611_01,M006959_01,M007009_01,M009524_01,M010368_01,M011496_01,M011796_01 GENE_SYMBOLS ,,,PVALB,,SOS2,,ACTN3,,,,,,,TNNC2,,,MYL7,, FOUNDER_NAMES