title: Arrest is a regulator of fiber-specific alternative splicing in the indirect flight muscles of Drosophila.
abstract: Drosophila melanogaster flight muscles are distinct from other skeletal muscles, such as jump muscles, and express several uniquely spliced muscle-associated transcripts. We sought to identify factors mediating splicing differences between the flight and jump muscle fiber types. We found that the ribonucleic acid-binding protein Arrest (Aret) is expressed in flight muscles: in founder cells, Aret accumulates in a novel intranuclear compartment that we termed the Bruno body, and after the onset of muscle differentiation, Aret disperses in the nucleus. Down-regulation of the aret gene led to ultrastructural changes and functional impairment of flight muscles, and transcripts of structural genes expressed in the flight muscles became spliced in a manner characteristic of jump muscles. Aret also potently promoted flight muscle splicing patterns when ectopically expressed in jump muscles or tissue culture cells. Genetically, aret is located downstream of exd (extradenticle), hth (homothorax), and salm (spalt major), transcription factors that control fiber identity. Our observations provide insight into a transcriptional and splicing regulatory network for muscle fiber specification.
authors.affiliation: Department of Biology, University of New Mexico, Albuquerque, NM 87131.
authors.forename: Sandy T
authors.initials: ST
authors.lastname: Oas
authors.affiliation: Department of Biology, University of New Mexico, Albuquerque, NM 87131 abryant@unm.edu rcripps@unm.edu.
authors.forename: Anton L
authors.initials: AL
authors.lastname: Bryantsev
authors.affiliation: Department of Biology, University of New Mexico, Albuquerque, NM 87131 abryant@unm.edu rcripps@unm.edu.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Cripps
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005426:Flight, Animal; D018507:Gene Expression Regulation, Developmental; D007438:Introns; D018482:Muscle, Skeletal / Q000196:embryology / Q000378:metabolism*; D021381:Protein Transport; D016601:RNA-Binding Proteins / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; D016601:RNA-Binding Proteins; C093437:bru1 protein, Drosophila