Distance and force production during jumping in wild-type and mutant Drosophila melanogaster
Distance and force production during jumping in wild-type and mutant Drosophila melanogaster
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DOI：
10.1242/jeb.01181
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发表时间：
2004-09-01
影响因子：
2.8
通讯作者：
Elliott, CJH
中科院分区：
文献类型：
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作者：
Zumstein, N;Forman, O;Elliott, CJH
在许多以跳跃能力著称的昆虫中，使用了弹性存储，以便在跳跃之前产生较大的力。我们结合了生理学、行为学和遗传学的方法来测试弹性能量存储是否对果蝇的跳跃做出了主要贡献。我们描述了一种灵敏的应变计装置，它测量被拴住的果蝇通过它们的胸间腿产生的力。来自野生型(广州-S)品系的雌蝇的主要跳跃肌肉产生的峰值力量为101+/-4.4mun[这与第二个野生型(德克萨斯州)品系没有区别]。这股力量需要8.2毫秒才能达到峰值。在75-120度范围内，改变腿角(股骨-胫骨关节角)对峰值力量的影响不明显，但随着腿的进一步伸展，峰值力量有所下降。跳跃能力(距离跳跃)的测量表明，广州-S和德克萨斯两个野生品系的雌性果蝇(去掉翅膀)产生的跳跃分别为28.6+/-0.7和30.2+/-1.0 mm(平均+/-S.E.M.)。对于雌性野生型果蝇来说，30毫米的跳跃相当于起飞时200nJ的动能(允许20%的能量来克服空气阻力)。我们建立了一个线性的力-时间起飞模型的运动方程，计算出起飞时间为5.0ms，最大力应为274mun(137 mun腿(-1))。我们从章鱼胺对几种蝗虫肌肉的增强肌肉张力的作用预测，如果储存的弹性能量不参与力量的发展，那么章鱼胺系统的遗传操作将直接影响果蝇的力量产生和跳跃。使用两个章胺能系统缺陷的突变体tbh(Nm18)(M18)和tyrR(Hono)(Hono)，我们发现与野生型相比，跳跃距离(分别为20.7+/-0.7 mm和20.7+/-0.4 mm)和力量产生(分别为52%和55%)显著减少。从缺乏章鱼胺合成的突变体m18和酪胺/章鱼受体突变体hono的距离和力量产生的减少来看，我们得出结论，在果蝇中，就像蝗虫一样，章鱼胺调节逃逸跳跃。我们的结论是，苍蝇不需要储存大量的弹性能量来进行跳跃，因为(1)测量和计算的力在40%以内，(2)突变体跳跃距离的减少与它们测量的峰值力的减少有很好的相关性。
In many insects renowned for their jumping ability, elastic storage is used so that high forces can be developed prior to jumping. We have combined physiological, behavioural and genetic approaches to test whether elastic energy storage makes a major contribution to jumping in Drosophila.We describe a sensitive strain gauge setup, which measures the forces produced by tethered flies through their mesothoracic legs. The peak force produced by the main jumping muscle of female flies from a wild-type (Canton-S) strain is 101+/-4.4 muN [and this is indistinguishable from a second wild-type (Texas) strain]. The force takes 8.2 ms to reach its peak. The peak force is not affected significantly by altering the leg angle (femur-tibia joint angle) in the range of 75-120degrees, but the peak force declines as the leg is extended further.Measurements of jumping ability (distance jumped) showed that female Drosophila (with their wings removed) of two wild-type strains, Canton-S and Texas, produced jumps of 28.6+/-0.7 and 30.2+/-1.0 mm (mean +/- S.E.M.). For a female wild-type Drosophila, a jump of 30 mm corresponds to a kinetic energy of 200 nJ on take-off (allowing 20% of the energy to overcome air resistance). We develop equations of motion for a linear force-time model of take-off and calculate that the time to take-off is 5.0 ms and the peak force should be 274 muN (137 muN leg(-1)).We predicted, from the role of octopamine in enhancing muscle tension in several locust muscles, that if stored elastic energy plays no part in force development, then genetic manipulation of the octopaminergic system would directly affect force production and jumping in Drosophila. Using two mutants deficient in the octopaminergic system, Tbh(nM18) (M18) and TyrR(hono) (hono), we found significantly reduced jumping distances (20.7+/-0.7 and 20.7+/-0.4 mm, respectively) and force production (52% and 55%, respectively) compared with wild type.From the reduced distance and force production in M18, a mutant deficient in octopamine synthesis, and in hono, a tyramine/octopamine receptor mutant, we conclude that in Drosophila, as in locusts, octopamine modulates escape jumping. We conclude that the fly does not need to store large quantities of elastic energy in order to make its jump because (1) the measured and calculated forces agree to within 40% and (2) the reduction in distances jumped by the mutants correlates well with their reduction in measured peak force.