根據果蠅調控其日夜週期的研究指出，控制果蠅日夜週期節律的細胞為一群位於腦內腹側的8顆細胞，稱為腹側神經元 ( ventral Lateral neurons ,LNvs)。 這些LNvs的神經分佈於果蠅兩邊的視葉和中央腦，並且會釋出一種稱做色素傳播因子 ( pigment dispersing factor, PDF) 的神經胜肽來控制其生理行為。 在我的研究上，由於近來許多基因轉殖果蠅的產生，讓我可以配合共軛交顯微鏡等影像技術來更進一步探討這8顆細胞的發育和神經網路。 Flip-out的技術讓我們知道單一顆細胞的表現型態；而利用表現在細胞膜上和只表現在細胞核中的綠螢光蛋白，並在發育中不同時期中解剖，讓我們可以知道pdf基因在腦內發育各個時期的表現和細胞數目。我也探討這些LNvs的軸突和樹突分佈，與之前人們猜測不同的是，我發現有數條由l-LNvs來的後視覺神經束 (posterior optic tract) 和數條從s-LNVs伸入中央腦的神經纖維是樹突。 除此之外，我也發現了這些LNvs所用的神經傳導物質不是乙烯膽鹼和章魚涎胺。 最後，我對於由我們實驗室所做的一株對紫外線敏感的果蠅UAS-Kaede做了一些討論，UAS-kaede能否用於解開這些LNvs的細胞出生時間和細胞血統 (cell lineage) 呢? 我認為，由於這些LNvs代謝速率很快的原因，使得我們很難去完全解開這些問題，但至少，kaede提供了我們一個新的方向和新的思維，將來，也許可以結合其他的影像技術諸如MARCM等等，來真正的完全解開這些所謂的時鐘細胞的神秘面紗。

The circadian researches in Drosophila melanogaster indicated that the fly pacemaker cells are 8 cells located on ventral bilateral of the brain called “lateral neurons” (LNvs). The expression patterns of these 8 cells innervate both optic lobes and central brain, and release a kind of neuropeptide called pigment-dispersing factor (PDF) served as behavior circadian. In my study, since many transgenic flies were produced recent years， I was able to express different reporters on these LNvs by UAS/GAL4 system and to study further the development and circuit of these LNvs. Flip-out let us known the expression pattern of single LNvs. Combing mCD8-GFP and nuclear localized GFP let us to know the pdf expression pattern and cell number during different developmental stages. In the study of the axonal and dendritic distribution of these LNvs, unlike previous guesses, I found that several posterior optic tracts (POT) originated from l-LNvs and fibers send to central brain from s-LNvs are dendrites. In addition, I also found Acetylcholine and octopamine are not the neurotransmitters used in LNvs. Finally, I used a UV sensitive fly “UAS-kaede” constructed by our lab to prove that the cell lineage between 3 instar larvae and adults. In aspect of cell birth, I think it is difficult to solve these questions entirely because the metabolic rate of LNvs is very fast. However, kaede do provide us a new direction and a new insight to study the development of these LNvs. In the future, we may combine more image techniques, like MARCM, to unravel the mystery of these clock neurons entirely.

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