Natural thermal stress and heat-shock protein expression in Drosophila larvae and pupae
Natural thermal stress and heat-shock protein expression in Drosophila larvae and pupae
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DOI：
10.1046/j.1365-2435.1997.00060.x
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发表时间：
1997-02-01
影响因子：
5.2
通讯作者：
Figueras, H
中科院分区：
文献类型：
--
作者：
Feder, ME;Blair, N;Figueras, H
1. 果蝇幼虫和蛹是否自然经历会导致热损伤或死亡的温度尚不清楚，但与果蝇热生物学和热休克反应的大量研究直接相关。据此，检测了果蝇幼虫和蛹栖息的坏死果的温度、实验室外幼虫和蛹的温度以及自然界中幼虫表达的热休克蛋白hsp 70的水平。 2．当坏死的果实受到阳光照射时，内部温度上升到可能伤害体内昆虫的水平，果实大小和蒸发水分损失会影响这些温度。田间幼虫和蛹的温度通常超过 35 摄氏度，活幼虫记录温度 >44 摄氏度，蛹温度 >41 摄氏度。自然死亡率明显，可能是由于高温所致。3．在实验室中，这些温度可迅速杀死幼虫，LT(50)s（杀死一半样品所需的时间）在 39 摄氏度下为 30 分钟，在 40 摄氏度下为 15 分钟，在 41 摄氏度下为 8.5 分钟。从 25 摄氏度逐渐转移到这些温度所导致的死亡率并不比直接转移低。使用 hsp 70 特异性抗体通过 ELISA（酶联免疫吸附测定）测量整个幼虫裂解物中的 Hsp 70 水平。对于通过实验从阴凉处转移到阳光下的坏死苹果内以及原位坏死果实内的幼虫，hsp 70 水平等于或超过对整个幼虫或培养细胞的平行实验室研究中检测到的水平5。这些数据为果蝇热应激和热休克反应的研究提供了迄今为止所缺乏的生态背景。
1. Whether Drosophila larvae and pupae naturally experience temperatures that can cause heat damage or death is poorly understood, but bears directly on numerous investigations of the thermal biology and heat-shock response in Drosophila. Accordingly, the temperatures of necrotic fruit, which Drosophila larvae and pupae inhabit, the temperatures of larvae and pupae outside the laboratory, and the levels of the heat-shock protein hsp 70 expressed by larvae in nature were examined.2. When necrotic fruit was sunlit,internal temperatures rose to levels that can harm indwelling insects, Fruit size and evaporative water loss affected these temperatures. Temperatures of larvae and pupae in the field commonly exceeded 35 degrees C, with living larvae recorded at >44 degrees C and pupae at >41 degrees C. Natural mortality was evident, presumably because of heat.3. In the laboratory, these temperatures kill larvae rapidly, with LT(50)s (time taken fur half the sample to be killed) of 30 min at 39 degrees C, 15 min at 40 degrees C and 8.5 min at 41 degrees C. Gradual transfer from 25 degrees C to these temperatures resulted in no lesser mortality than did direct transfer4. Hsp 70 levels in lysates of whole larvae were measured by ELISA (enzyme-link immunosorbent assay) with an hsp 70-specific antibody. For larvae within necrotic apples experimentally transferred from shade to sun and within necrotic fruit in situ, hsp 70 levels equalled or exceeded levels detected in parallel laboratory studies of whole larvae or cells in culture,5. These data provide an ecological context for studies of thermal stress and the heat-shock response in Drosophila that has heretofore been lacking.