title: Extradenticle and homothorax control adult muscle fiber identity in Drosophila.
abstract: Here we identify a key role for the homeodomain proteins Extradenticle (Exd) and Homothorax (Hth) in the specification of muscle fiber fate in Drosophila. exd and hth are expressed in the fibrillar indirect flight muscles but not in tubular jump muscles, and manipulating exd or hth expression converts one muscle type into the other. In the flight muscles, exd and hth are genetically upstream of another muscle identity gene, salm, and are direct transcriptional regulators of the signature flight muscle structural gene, Actin88F. Exd and Hth also impact muscle identity in other somatic muscles of the body by cooperating with Hox factors. Because mammalian orthologs of exd and hth also contribute to muscle gene regulation, our studies suggest that an evolutionarily conserved genetic pathway determines muscle fiber differentiation.
authors.affiliation: Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
authors.forename: Anton L
authors.initials: AL
authors.lastname: Bryantsev
authors.forename: Sandy
authors.initials: S
authors.lastname: Duong
authors.forename: Tonya M
authors.initials: TM
authors.lastname: Brunetti
authors.forename: Maria B
authors.initials: MB
authors.lastname: Chechenova
authors.forename: TyAnna L
authors.initials: TL
authors.lastname: Lovato
authors.forename: Cloyce
authors.initials: C
authors.lastname: Nelson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Shaw
authors.forename: Juli D
authors.initials: JD
authors.lastname: Uhl
authors.forename: Brian
authors.initials: B
authors.lastname: Gebelein
authors.forename: Richard M
authors.initials: RM
authors.lastname: Cripps
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004330:Drosophila / Q000166:cytology / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C083405:exd protein, Drosophila; C108704:hth protein, Drosophila