Department of Entomology, The Ohio State University, 318 W. 12th Ave., Columbus, OH 43210, USA.
J Insect Physiol. 2011 Jan;57(1):203-10. doi: 10.1016/j.jinsphys.2010.11.007. Epub 2010 Nov 21.
In this study, pharate adults of the flesh fly Sarcophaga crassipalpis were exposed to two, four, seven, or ten days of severe hypoxia (3% oxygen) to evaluate its impact on emergence and the expression of genes encoding heat shock proteins (Hsps) and heat shock regulatory elements. A four-day exposure to hypoxia significantly reduced survival, but more than seven days was required to reach the LD(50). Eight genes encoding Hsps, at least one from each major family of Hsps (Hsp90, Hsp70, Hsp60, Hsp40, and sHsps) and two genes encoding proteins involved in Hsp regulation (heat shock factor, hsf, and sirtuin) were cloned, and expression levels were assessed during and after hypoxia using qRT-PCR. Most, but not all hsps studied, were significantly up-regulated during hypoxia, and expression levels for most of the hsps reverted to control levels a few hours after return to normoxia. Hsp70 was the most responsive to hypoxia, increasing expression several hundred fold. By contrast, hsp90 and hsp27 showed little response to hypoxia but did respond to recovery. Neither hsf nor sirtuin were elevated by hypoxia, an observation consistent with their assumed post-transcriptional regulatory roles. These data demonstrate a strong Hsp response to hypoxia, suggesting an important role for Hsps in responding to low oxygen environments.
在这项研究中，将肉蝇 Sarcophaga crassipalpis 的预成体成虫暴露于严重缺氧（3%氧气）2、4、7 或 10 天，以评估其对出蛹和热休克蛋白（Hsps）和热休克调节元件编码基因表达的影响。四天的缺氧暴露显著降低了存活率，但需要超过七天才能达到 LD（50）。克隆了至少来自 Hsp 各主要家族（Hsp90、Hsp70、Hsp60、Hsp40 和 sHsps）的一个编码 Hsps 的 8 个基因和两个参与 Hsp 调节的基因（热休克因子 hsf 和 sirtuin），并使用 qRT-PCR 在缺氧期间和之后评估了它们的表达水平。大多数（但不是全部）研究的 hsps 在缺氧期间显著上调，并且大多数 hsps 的表达水平在返回常氧数小时后恢复到对照水平。Hsp70 对缺氧最敏感，表达水平增加了数百倍。相比之下，hsp90 和 hsp27 对缺氧的反应很小，但对恢复有反应。hsf 和 sirtuin 都没有被缺氧上调，这一观察结果与它们假定的转录后调节作用一致。这些数据表明对缺氧有强烈的 Hsp 反应，表明 Hsps 在应对低氧环境中起着重要作用。
