Lehmann, Fritz-Olaf and Dickinson, Michael H. (1997) The changes in power requirements and muscle efficiency during elevated force production in the fruit fly Drosophila melanogaster. Journal of Experimental Biology, 200 (7). pp. 1133-1143. ISSN 0022-0949 http://resolver.caltech.edu/CaltechAUTHORS:20120119-134025923
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The limits of flight performance have been estimated in tethered Drosophila melanogaster by modulating power requirements in a 'virtual reality' flight arena. At peak capacity, the flight muscles can sustain a mechanical power output of nearly 80 W kg^(-1) muscle mass at 24 °C, which is sufficient to generate forces of approximately 150% of the animal's weight. The increase in flight force above that required to support body weight is accompanied by a rise in wing velocity, brought about by an increase in stroke amplitude and a decrease in stroke frequency. Inertial costs, although greater than either profile or induced power, would be minimal with even modest amounts of elastic storage, and total mechanical power energy should be equivalent to aerodynamic power alone. Because of the large profile drag expected at low Reynolds numbers, the profile power was approximately twice the induced power at all levels of force generation. Thus, it is the cost of overcoming drag, and not the production of lift, that is the primary requirement for flight in Drosophila melanogaster. By comparing the estimated mechanical power output with respirometrically measured total power input, we determined that muscle efficiency rises with increasing force production to a maximum of 10%. This change in efficiency may reflect either increased crossbridge activation or a favorable strain regime during the production of peak forces.
|Additional Information:||© 1997 The Company of Biologists Limited. Accepted 24 January 1997. This project was generously funded by a Packard Foundation Fellowship and NSF grant IBN-9208765 (to M.H.D.) and a DFG Post-Doctoral Fellowship (to F.-O.L.). The authors wish to acknowledge David Smith, Gerard Jendraszkiewicz and Brian Goers of the James Franck Institute at the University of Chicago for their work in the design and construction of the flight arena and Jeff Hamlin for his help with morphometric measurements.|
|Subject Keywords:||fruit fly; Drosophila melanogaster; power requirement; flight; muscle efficiency; aerodynamics; respirometry|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||13 Apr 2012 21:21|
|Last Modified:||26 Dec 2012 14:43|
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