title: Extraocular muscle is defined by a fundamentally distinct gene expression profile.
abstract: Skeletal muscle fibers are defined by patterned covariation of key traits that determine contractile and metabolic characteristics. Although the functional properties of most skeletal muscles result from their proportional content of a few conserved muscle fiber types, some, typically craniofacial, muscles exhibit fiber types that appear to lie outside the common phenotypic range. We analyzed gene expression profiles of three putative muscle classes, limb, masticatory, and extraocular muscle (EOM), in adult mice by high-density oligonucleotide arrays. Pairwise comparisons using conservative acceptance criteria identified expression differences in 287 genes between EOM and limb and/or masticatory muscles. Use of significance analysis of microarrays methodology identified up to 400 genes as having an EOM-specific expression pattern. Genes differentially expressed in EOM reflect key aspects of muscle biology, including transcriptional regulation, sarcomeric organization, excitation-contraction coupling, intermediary metabolism, and immune response. These patterned differences in gene expression define EOM as a distinct muscle class and may explain the unique response of these muscles in neuromuscular diseases.
authors.affiliation: Department of Ophthalmology, Case Western Reserve University, Cleveland, OH 44106, USA. jdp7@po.cwru.edu
authors.forename: J D
authors.initials: JD
authors.lastname: Porter
authors.forename: S
authors.initials: S
authors.lastname: Khanna
authors.forename: H J
authors.initials: HJ
authors.lastname: Kaminski
authors.forename: J S
authors.initials: JS
authors.lastname: Rao
authors.forename: A P
authors.initials: AP
authors.lastname: Merriam
authors.forename: C R
authors.initials: CR
authors.lastname: Richmonds
authors.forename: P
authors.initials: P
authors.lastname: Leahy
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: F H
authors.initials: FH
authors.lastname: Andrade
mesh_terms: D000818:Animals; D015870:Gene Expression; D020869:Gene Expression Profiling; D008297:Male; D008410:Masticatory Muscles / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000276:immunology / Q000378:metabolism; D009468:Neuromuscular Diseases / Q000235:genetics; D009801:Oculomotor Muscles / Q000276:immunology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010641:Phenotype; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics
chemical_list: D014157:Transcription Factors