Lane Steven J, Frankino W Anthony, Elekonich Michelle M, Roberts Stephen P
Department of Biology, Central Michigan University, Mt Pleasant, MI 48858, USA.
J Exp Biol. 2014 May 1;217(Pt 9):1437-43. doi: 10.1242/jeb.095646.
The effects of flight behavior on physiology and senescence may be profound in insects because of the extremely high metabolic costs of flight. Flight capacity in insects decreases with age; in contrast, limiting flight behavior extends lifespan and slows the age-related loss of antioxidant capacity and accumulation of oxidative damage in flight muscles. In this study, we tested the effects of age and lifetime flight behavior on flight capacity by measuring wingbeat frequency, the ability to fly in a hypo-dense gas mixture, and metabolic rate in Drosophila melanogaster. Specifically, 5-day-old adult flies were separated into three life-long treatments: (1) those not allowed to fly (no flight), (2) those allowed - but not forced - to fly (voluntary flight) and (3) those mechanically stimulated to fly (induced flight). Flight capacity senesced earliest in flies from the no-flight treatment, followed by the induced-flight group and then the voluntary flight group. Wingbeat frequency senesced with age in all treatment groups, but was most apparent in the voluntary- and induced-flight groups. Metabolic rate during agitated flight senesced earliest and most rapidly in the induced flight group, and was low and uniform throughout age in the no-flight group. Early senescence in the induced-flight group was likely due to the acceleration of deleterious aging phenomena such as the rapid accumulation of damage at the cellular level, while the early loss of flight capacity and low metabolic rates in the no-flight group demonstrate that disuse effects can also significantly alter senescence patterns of whole-insect performance.
由于飞行的代谢成本极高，飞行行为对昆虫生理和衰老的影响可能极为深远。昆虫的飞行能力会随着年龄增长而下降；相反，限制飞行行为可延长寿命，并减缓飞行肌肉中与年龄相关的抗氧化能力丧失以及氧化损伤的积累。在本研究中，我们通过测量黑腹果蝇的翅膀拍击频率、在低密度气体混合物中飞行的能力以及代谢率，来测试年龄和终生飞行行为对飞行能力的影响。具体而言，将5日龄的成年果蝇分为三种终生处理组：（1）不允许飞行的果蝇（无飞行组），（2）允许但不强迫飞行的果蝇（自愿飞行组），以及（3）机械刺激飞行的果蝇（诱导飞行组）。无飞行组的果蝇飞行能力衰老最早，其次是诱导飞行组，然后是自愿飞行组。所有处理组的翅膀拍击频率均随年龄增长而衰老，但在自愿飞行组和诱导飞行组中最为明显。诱导飞行组在剧烈飞行期间的代谢率衰老最早且最快，而无飞行组在整个年龄段的代谢率都很低且较为一致。诱导飞行组的早期衰老可能是由于有害衰老现象加速，例如细胞水平的损伤快速积累，而无飞行组飞行能力的早期丧失和低代谢率表明，废用效应也可显著改变昆虫整体性能的衰老模式。
