条纹小斑蛾滞育解除的光周期时间测量特性及滞育解除的基因表达

In most published cases, the duration of the night is more important than that of the day in the determination of diapause, i.e. the photoperiodic clock only measured the dark period. However, it has shown that the zygaenid moth, Thyrassia penangae, unlike most insect species, ‘measures’ daylength rather than nightlength in photoperiodic induction of diapause. In the present study, the photoperiodic time measurement for diapause termination in T. penangae will be systematically investigated by testing (1) photoperiodic responses for diapasue termination under 24-h and non-24-h light–dark cycles; (2) the influence of low temperature on diapause termination; (3) night-interruption experiments for diapause termination under 24-h and non-24-h photoperiods; (4) diapause termination in Nanda-Hamner and Bünsow experiments; (5) the differences of transcriptome between diapausing individuals kept in a diapause-terminating long photoperiod and diapausing individuals kept in a diapause-maintaining short photoperiod by using RNA-Seq analysis. Through these studies, we try to reveal whether the photoperiodic time measurement for diapause termination in this moth is also based on daylength measurement, and to identify the photoperiodic response genes relation to diapause termination. The results from these studies will provide new insight and the basic materials for analyzing the time measurement and the construction and mechanisms of photoperiodic clock.

绝大多数昆虫光周期反应的研究揭示了暗期的长度在滞育的决定中发挥了关键作用，即昆虫的光周期钟只测量了暗期。然而，条纹小斑蛾Thracian penangae光周期反应则显示了光期的长度比暗期的长度更为重要。本项目拟系统研究条纹小斑蛾滞育解除的光周期时间测量特性及滞育解除过程中基因表达。研究内容包括：（1）24-h和非24-h昼夜循环的光周期反应;（2）低温对幼虫滞育解除的影响;（3）24-h和非24-h循环的夜间干扰试验;（4）光周期钟的共鸣试验和Bünsow试验; （5）采用 RNA-Seq 转录组测序和生物信息学分析，比较条纹小斑蛾滞育个体在滞育解除的长光周期和滞育维持的短光周期下转录组差异。通过这些研究，我们试图探明是否该虫滞育解除的光周期时间测量也是基于日长的测量; 鉴定参与滞育解除光周期基因。研究结果将为阐明和分析昆虫光周期钟的结构和机制提供新的思路和基础资料。

绝大多数昆虫光周期反应的研究揭示了暗期的长度在滞育的决定中发挥了关键作用，即昆虫的光周期钟只测量了暗期。然而，条纹小斑蛾Thyrassia penangae光周期反应则显示了光期的长度比暗期的长度更为重要。本项目从以下方面进行了研究，取得以下重要成果。（1）非24h昼夜循环的光周期反应试验：揭示了当光期长度大于临界日长，滞育率都很低，与暗期持续长度无关。（2）光周期钟的Bünsow试验：揭示了当被暗期干扰的光期大于临界日长时，滞育率都很低，没有出现昼夜节律性。以上两个试验进一步证明了该虫测量的是日长而不是夜长。（3）温度和光周期对滞育强度的影响试验：揭示了滞育期间的温度对条纹小斑蛾的滞育强度有显著影响，而滞育诱导的光周期对条纹小斑蛾的滞育强度影响不大。（4）温度和光周期对羽化和交配节律的影响试验：揭示了羽化高峰期随着温度升高而提前，成虫羽化时间基本不受光周期的影响；交配时间随日长的延长而推迟，交配时间受温度的影响较小。以上研究结果为阐明和分析昆虫光周期钟的结构和机制提供新的思路和基础资料。