RNA interference of the clock gene period disrupts circadian rhythms in the cricket Gryllus bimaculatus
RNA interference of the clock gene period disrupts circadian rhythms in the cricket Gryllus bimaculatus
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DOI：
10.1177/0748730408320486
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发表时间：
2008-08-01
影响因子：
3.5
通讯作者：
Tomioka, Kenji
中科院分区：
文献类型：
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作者：
Moriyama, Yoshiyuki;Sakamoto, Tomoaki;Tomioka, Kenji
所谓的时钟基因的周期性表达是生物钟的重要组成部分。在果蝇中，per和tim通过自动调节反馈环的循环表达被认为在昼夜节律的产生中起核心作用。然而，这一假设是否适用于其他昆虫物种仍然是难以捉摸的。在这里，它表明，每一个基因在蟋蟀节律的产生中起着关键作用。在视叶的每mRNA水平的测量揭示了节奏的表达，每在光周期与高峰在深夜到深夜，持续在恒定的黑暗。将每双链RNA（dsRNA）单次注射到末龄幼虫的腹部中，有效地将成虫的mRNA水平敲低至对照动物的约50%。在持续黑暗条件下，大多数注射过dsRNA的蟋蟀在注射后50天内完全丧失了昼夜运动活动节律，而注射过DsRed2 dsRNA的蟋蟀则明显保持了昼夜运动活动节律，并且视叶传出神经的电活动也变得异常。这些结果不仅表明PER在蟋蟀的昼夜节律产生中起着重要作用，而且还表明RNA干扰是剖析蟋蟀昼夜节律的分子机制的有力工具。
Periodic expression of so-called clock genes is an essential part of the circadian clock. In Drosophila melanogaster the cyclic expression of per and tim through an autoregulatory feedback loop is believed to play a central role in circadian rhythm generation. However, it is still elusive whether this hypothesis is applicable to other insect species. Here it is shown that per gene plays a key role in the rhythm generation in the cricket Gryllus bimaculatus. Measurement of per mRNA levels in the optic lobe revealed the rhythmic expression of per in light cycles with a peak in the late day to early night, persisting in constant darkness. A single injection of per double-stranded RNA ( dsRNA) into the abdomen of the final instar nymphs effectively knocked down the mRNA levels as adult to about 50% of control animals. Most of the per dsRNA-injected crickets completely lost the circadian locomotor activity rhythm in constant darkness up to 50 days after the injection, whereas those injected with DsRed2 dsRNA as a negative control clearly maintained it. The electrical activity of optic lobe efferents also became arrhythmic in the per dsRNA-injected crickets. These results not only suggest that per plays an important role in the circadian rhythm generation also in the cricket but also show that RNA interference is a powerful tool to dissect the molecular machinery of the cricket circadian clock.