摘要：日週時鐘是從單細胞生物到人類都有的內在計時系統，其讓生物在分子、生理、行為各層面表現出日週律動。截至目前為止，絕大多數關於日週時鐘的分子機制的了解都來自於在黃果蠅的遺傳與生化研究。第一個時鐘基因 (period)在果蠅被廣泛的分析，其日週律動的表現乃是藉由本身的蛋白質產物 (PER) 對 per 基因轉錄的負回匱來達成。最近per 基因在許多昆蟲都被選殖出來，包括鱗翅目、蜚蠊、非果蠅的雙翅目以及蜜蜂等，其中社會性昆蟲的研究相當缺乏。研究發現蜜蜂工蜂職務分工的發展與per 基因的表現程度有關。因此，為了了解per基因的表現如何影響社會性昆蟲的職務分工，蚜蟲 (非常原始社會性昆蟲) 可能是探討這個問題的好材料。舉例來說，某些蚜蟲行孤雌生殖產生的部份後代個體會變成表現利他行為的兵蚜，其犧牲自身的生殖能力以維護同群其它個體的生殖利益。兵蚜這種生殖與利他行為的權衡 (trade-off) 可用來探討per 基因的表現與階級分化的關係。 另一方面，最新的研究顯示果蠅的per 基因在卵巢並沒有日週律動，由此推測該基因在果蠅的卵巢可能有其它未知的功能；由於蚜蟲的生活史為無性及有性世代的循環而且其生殖策
Abstract: Circadian clocks are endogenous timing systems that control molecular, cellular, physiological, and behavioral rhythms in all organisms from unicellular organisms to humans. Up to date, the knowledge about the molecular mechanisms responsible for circadian clocks comes largely from genetic and biochemical studies in Drosophila melanogaster. The first clock gene (period, per) was extensively characterized, and rhythmic expression of per gene caused by negative feedback in which transcription of the per gene is regulated by its protein product (PER) in Drosophila. Recently, per genes were cloned in many insects, including Lepidoptera, cockroach and dipteran species other than Drosophila and honey bee (Toma et al., 2000; Shimizu et al., 2001), while other social insects remained neglected. The ontogenic development of division of labor as well as expression of per gene was reported in honeybee workers. Therefore, in order to realize expression of per gene how to affect the caste determination in social insects. Aphid (a very primitive social insect) is a good model to explore this question. For example, some aphids parthenogenetically produce solider individuals that altruistically sacrifice their own reproduction for the benefit of their colony mates. The trade-off between reproduction and altruistic functions in soldier aphid could be used to realize the relationship between expression of per gene and caste differentiation. On the other hand, the study indicated that per gene is involved in an unknown non-circadian function in the ovary of Drosophila. Since the basic life cycle of an aphid is characterized by the alternation of sexual and asexual reproduction which depends on seasonality, a photoperiodic clock is though to be involved in the regulation of reproduction. Two aphids including pea aphid (Acyrthosiphon pisum) (model species in aphid) and one soldier-producing aphid (Pseudoregma bambucicola) are used to explore two questions in this project: the first is the effects of photoperiod on the expression of per gene, the second is per gene whether is involved in caste determination, the third is to analyze whether the expression of per gene in ovary of aphid as well as that of Drosophila.