The physiological mechanisms underlying photoperiodism in insects have been studied extensively, although the associated molecular machinery remains largely unknown. In the present study, we investigate the roles of the circadian clock gene cycle (cyc) and the endocrine regulator gene myoinhibitory peptide (Mip) in the photoperiodic response of the brown‐winged green bug Plautia stali Scott (Hemiptera, Pentatomidae). Typically, adult females of this species develop their ovaries under long‐day conditions, whereas they suppress its development under short‐day conditions. We find that RNA interference (RNAi) directed against cyc causes malfunction of the circadian clock governing the locomotor activity rhythm and yields abnormal activity profiles not only under constant darkness, but also under light/dark conditions. RNAi directed against cyc and Mip disrupts the photoperiodic response in ovarian development. cyc RNAi suppresses the ovarian development even under long‐day conditions, whereas Mip RNAi induces it even under short‐day conditions. We propose that the core circadian clock gene cyc regulates the photoperiodic response and that Mip is the causal regulator of juvenile hormone biosynthesis in the corpus allatum. Neither photoperiod, nor cyc RNAi affect Mip mRNA levels, and therefore it remains unknown how the photoperiodic information is processed and mediated by Mip.

中文翻译：

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生物钟和内分泌调节剂在棕翅绿虫 Plautia stali 光周期反应中的作用

昆虫光周期的生理机制已被广泛研究，尽管相关的分子机制在很大程度上仍是未知的。在本研究中，我们研究了生物钟基因周期 (cyc) 和内分泌调节基因肌抑制肽 (Mip) 在褐翅绿虫 Plautia stali Scott（半翅目，五足科）的光周期反应中的作用。通常，该物种的成年雌性在长日照条件下发育卵巢，而在短日照条件下抑制卵巢发育。我们发现针对 cyc 的 RNA 干扰 (RNAi) 会导致控制运动活动节律的生物钟出现故障，并且不仅在持续黑暗下，而且在明/暗条件下都会产生异常的活动特征。针对 cyc 和 Mip 的 RNAi 破坏了卵巢发育中的光周期反应。即使在长日照条件下，cyc RNAi 也能抑制卵巢发育，而 Mip RNAi 即使在短日照条件下也能诱导卵巢发育。我们提出核心生物钟基因 cyc 调节光周期反应，而 Mip 是 corpus allatum 中保幼激素生物合成的因果调节剂。光周期和 cyc RNAi 均不影响 Mip mRNA 水平，因此尚不清楚 Mip 如何处理和介导光周期信息。我们提出核心生物钟基因 cyc 调节光周期反应，而 Mip 是 corpus allatum 中保幼激素生物合成的因果调节剂。光周期和 cyc RNAi 均不影响 Mip mRNA 水平，因此尚不清楚 Mip 如何处理和介导光周期信息。我们提出核心生物钟基因 cyc 调节光周期反应，而 Mip 是 corpus allatum 中保幼激素生物合成的因果调节剂。光周期和 cyc RNAi 均不影响 Mip mRNA 水平，因此尚不清楚 Mip 如何处理和介导光周期信息。