Effects of Tropomyosin Deficiency in Flight Muscle of Drosophila Melanogaster

摘要: We have studied the structure and function of muscle fibers in which tropomyosin stoichiometry has been reduced by genetic mutation. used a Drosophila melanogaster flightless mutant Ifm(3)3 cross this with wild type flies to achieve gradation gene dosage. measured flight ability wingbeat frequency live insects ultrastructure mechanochemistry isolated single fibers. Flight is impaired when dosage reduced. Wingbeat also depends upon as well severity myofilament lattice disruption number myofilaments organized core myofibrils. A reduction appears result active stiffness without resulting an appreciable change kinetics force production. trapped relaxed state cannot generate force. However, tight-binding rigor cross-bridges are able form; absence ATP, high