title: A genetic deficiency that spans the flightin gene of Drosophila melanogaster affects the ultrastructure and function of the flight muscles.
abstract: We have developed a reverse-genetic approach to study the function of flightin, a unique protein of the flight muscle myofibril of Drosophila melanogaster. We describe the generation and characterization of Df(3L)fln1, a lethal genetic deficiency in the 76BE region of the third chromosome which deletes several genes, including the gene for flightin. We show that heterozygous flies harboring the Df(3L)fln1 mutation exhibit both impaired flight and ultrastructural defects in their flight muscle myofibrils. We found that the mutation does not interfere with assembly of the myofibril but leads to disorganization of peripheral myofilaments in adult myofibrils. Most myofibrils, nevertheless, retain an intact core that represents approximately 80 % of the normal lattice diameter. Mechanical analysis of single skinned flight muscle fibers demonstrates that the mutation has no significant effect on net power output but increases the frequency at which maximum power is delivered to the wings, potentially reducing the overall performance of the flight system. The results suggest that flightin is an indispensable part of the flight muscle contractile mechanism.
authors.affiliation: Department of Biology and Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA. jvigorea@zoo.uvm.edu
authors.forename: J O
authors.initials: JO
authors.lastname: Vigoreaux
authors.forename: C
authors.initials: C
authors.lastname: Hernandez
authors.forename: J
authors.initials: J
authors.lastname: Moore
authors.forename: G
authors.initials: G
authors.lastname: Ayer
authors.forename: D
authors.initials: D
authors.lastname: Maughan
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000648:ultrastructure; D064448:Filamins; D005426:Flight, Animal; D017353:Gene Deletion; D007700:Kinetics; D008854:Microscopy, Electron; D009119:Muscle Contraction / Q000235:genetics / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics* / Q000502:physiology; D009132:Muscles / Q000648:ultrastructure*; D009154:Mutation; D009210:Myofibrils / Q000648:ultrastructure
chemical_list: D029721:Drosophila Proteins; D064448:Filamins; D009124:Muscle Proteins; C081072:fln protein, Drosophila; D002118:Calcium