Vitellogenin-RNAi and ovariectomy each increase lifespan, increase protein storage, and decrease feeding, but are not additive in grasshoppers.
Vitellogenin-RNAi and ovariectomy each increase lifespan, increase protein storage, and decrease feeding, but are not additive in grasshoppers.
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DOI：
10.1007/s10522-015-9599-3
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发表时间：
2015-12
期刊：
影响因子：
4.5
通讯作者：
Hatle JD
中科院分区：
文献类型：
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作者：
Tetlak AG;Burnett JB;Hahn DA;Hatle JD
在许多动物中，减少繁殖已被证明可以延长寿命，但这种权衡背后的机制尚不清楚。我们通过结合两种不同的、直接的通过减少繁殖来延长寿命的方法来解决这个问题，以测试它们是否是相加的。在较笨的蚱蜢中，切除卵巢（OVX）的个体相对于对照（假手术）的寿命增加了约20%，储存量增加了一倍。同样，用针对卵黄蛋白原（蛋黄蛋白的前体）的RNAi治疗的年轻雌性蚱蜢增加了脂肪体质量并停止了卵巢生长。在这项研究中，我们将VgRNAi与两个不减少繁殖的对照组进行了比较，即缓冲液注射（Buffer）和注射针对六聚体储存蛋白的RNAi（Hex 90 RNAi）。在有和没有卵巢切除术的情况下测试每种注射处理。因此，我们在六个组中测试了进食、储存和寿命：OVX和缓冲液、OVX和Hex 90 RNAi、OVX和VgRNAi、假手术和缓冲液、假手术和Hex 90 RNAi以及假手术和VgRNAi。卵巢切除的蚱蜢和VgRNAi蚱蜢各自具有相似的摄食减少（~ 40%）、血淋巴中蛋白质储存增加（150- 300%）和寿命延长（13- 21%）。卵巢切除的蚱蜢具有比VgRNAi蚱蜢更高的卵黄蛋白原蛋白水平。最后但并非最不重要的是，当卵巢切除术和VgRNAi一起应用时，对进食，蛋白质储存或寿命没有更大的影响。因此，昆虫的摄食调节和蛋白质储存可能是通过减少繁殖延长寿命的保守组成部分。
Reduced reproduction has been shown to increase lifespan in many animals, yet the mechanisms behind this trade-off are unclear. We addressed this question by combining two distinct, direct means of life-extension via reduced reproduction, to test whether they were additive. In the lubber grasshopper,Romalea microptera, ovariectomized (OVX) individuals had a ~20 % increase in lifespan and a doubling of storage relative to controls (Sham operated). Similarly, young female grasshoppers treated with RNAi against vitellogenin (the precursor to egg yolk protein) had increased fat body mass and halted ovarian growth. In this study, we compared VgRNAi to two control groups that do not reduce reproduction, namely buffer injection (Buffer) and injection with RNAi against a hexameric storage protein (Hex90RNAi). Each injection treatment was tested with and without ovariectomy. Hence, we tested feeding, storage, and lifespans in six groups: OVX and Buffer, OVX and Hex90RNAi, OVX and VgRNAi, Sham and Buffer, Sham and Hex90RNAi, and Sham and VgRNAi. Ovariectomized grasshoppers and VgRNAi grasshoppers each had similar reductions in feeding (~40 %), increases in protein storage in the hemolymph (150–300 %), and extensions in lifespan (13–21 %). Ovariectomized grasshoppers had higher vitellogenin protein levels than did VgRNAi grasshoppers. Last but not least, when ovariectomy and VgRNAi were applied together, there was no greater effect on feeding, protein storage, or longevity. Hence, feeding regulation, and protein storage in insects, may be conserved components of life-extension via reduced reproduction.