title: Adult Muscle Formation RequiresDrosophilaMoleskin for Proliferation of Wing Disc-Associated Muscle Precursors.
abstract: Adult muscle precursor (AMP) cells located in the notum of the larval wing disc undergo rapid amplification and eventual fusion to generate theDrosophila melanogasterindirect flight muscles (IFMs). Here we find that loss of Moleskin (Msk) function in these wing disc-associated myoblasts reduces the overall AMP pool size, resulting in the absence of IFM formation. This myoblast loss is due to a decrease in the AMP proliferative capacity and is independent of cell death. In contrast, disruption of Msk during pupal myoblast proliferation does not alter the AMP number, suggesting that Msk is specifically required for larval AMP proliferation. It has been previously shown that Wingless (Wg) signaling maintains expression of the Vestigial (Vg) transcription factor in proliferating myoblasts. However, other factors that influence Wg-mediated myoblast proliferation are largely unknown. Here we examine the interactions between Msk and the Wg pathway in regulation of the AMP pool size. We find that a myoblast-specific reduction of Msk results in the absence of Vg expression and a complete loss of the Wg pathway readout β-catenin/Armadillo (Arm). Moreover,msk RNA interferenceknockdown abolishes expression of the Wg target Ladybird (Lbe) in leg disc myoblasts. Collectively, our results provide strong evidence that Msk acts through the Wg signaling pathway to control myoblast pool size and muscle formation by regulating Arm stability or nuclear transport.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506.
authors.forename: Kumar
authors.initials: K
authors.lastname: Vishal
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506.
authors.forename: David S
authors.initials: DS
authors.lastname: Brooks
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506.
authors.forename: Simranjot
authors.initials: S
authors.lastname: Bawa
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506.
authors.forename: Samantha
authors.initials: S
authors.lastname: Gameros
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506.
authors.forename: Marta
authors.initials: M
authors.lastname: Stetsiv
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506 geisbrechte@ksu.edu.
authors.forename: Erika R
authors.initials: ER
authors.lastname: Geisbrecht
mesh_terms: D000818:Animals; D051186:Armadillo Domain Proteins / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D018398:Homeodomain Proteins / Q000235:genetics*; D007814:Larva / Q000235:genetics / Q000254:growth & development; D024510:Muscle Development / Q000235:genetics; D032446:Myoblasts / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics*; D014921:Wings, Animal / Q000254:growth & development; D051155:Wnt1 Protein / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C086967:Lbe protein, Drosophila; D009687:Nuclear Proteins; D014157:Transcription Factors; D051155:Wnt1 Protein; C095064:vg protein, Drosophila; C074622:wg protein, Drosophila
keywords: Drosophila melanogaster; Moleskin; indirect flight muscles; proliferation