臺灣博碩士論文加值系統

生物要維持生存與生殖，對環境中的變化要有應變的能力，而反應能力的降低，是老化的一種現象。反應能力的降低，有可能是生活史中累積的傷害所造成。在果蠅（Drosophila melanogaster），已經知道熱壓力與γ-ray照射所導致的傷害會降低果蠅壽命、促進果蠅老化。近年來紫外輻射對生物所造成的傷害（包括老化）逐漸受到重視。在本研究中，我們利用特別設計的UV照射器，來觀察混合光源紫外輻射（UVR）對果蠅成蟲的影響。實驗結果顯示：（一）UVR對果蠅的致死效應會受到溫度的影響，例如兩天大果蠅連續照射48 h 的UV，當照射時環境溫度上升為31℃時，其平均存活率較28℃下降12%。（二）年輕果蠅對UVR的耐受力較年老果蠅好，例如5天大的果蠅其耐受力是一個月大的果蠅的1.5倍。（三）年輕果蠅抗UVR的能力是可以誘導的。例如兩天大的果蠅施予15 h的UVR前處理，於7天大時照射48 h 的UV，其存活率較對照組提高約20%。

The ability of an organism to react to unfavorable environmental changes is crucial for survival and reproduction. And decline in that ability may be a result of random damage that is incurred and accumulates throughout the life span of an organism. It has been reported that in fruit flies (Drosophila melanogaster) the damage caused by elevated temperature and γ-ray radiation could shorten the life span and accelerate the rate of aging. We are interested in knowing factors that influence the lethal effect of UV radiation (UVR). In this studying, we used an UV irradiator that provided broad-spectrum UVR (including UVA, UVB and UVC) on adult fruit flies. Our results are summarized as follows. (1) The lethal effect of UVR is influenced by ambient temperature: the survival of flies exposed to 48 h UVR on the 2nd day after eclosion was reduced 12% when the temperature was elevated from 28℃ to 31℃. (2) Young flies are higher in UVR resistance than old flies: resistance in two-day-old flies was 1.5 times that of one-month-old flies. (3) The UVR resistance was found to be inducible in young flies: pretreatment with 15-h UVR on the 2nd day after eclosion resulted in 20% higher survival against a 48-h UVR challenge than that of control.

1. 中文摘要……………………………………………………………1
2. 英文摘要……………………………………………………………2
3. 前言…………………………………………………………………3
4. 材料與方法…………………………………………………………5
5. 結果…………………………………………………………………9
6. 討論…………………………………………………………………13
7. 參考文獻…………………………………………………………….18
8. 圖表…………………………………………………………………..i

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