Physiological effect of mild thermal stress and its induction of gene expression in the common cutworm, Spodoptera litura.
Physiological effect of mild thermal stress and its induction of gene expression in the common cutworm, Spodoptera litura.
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DOI：
10.1016/j.jinsphys.2013.12.007
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发表时间：
2014-02
影响因子：
2.2
通讯作者：
Ying Shen;Yan-Jun Gong;J. Gu;Li-Hua Huang;Q. Feng
中科院分区：
文献类型：
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作者：
Ying Shen;Yan-Jun Gong;J. Gu;Li-Hua Huang;Q. Feng
热休克蛋白（Hsp）及其同源蛋白（Hsc）在帮助昆虫在极端温度下生存中起着重要作用。然而，高水平的Hsp表达往往会给生物体带来负面的生理效应。这种权衡的机制尚不清楚。以鳞翅目昆虫斜纹夜蛾（Spodoptera litura）为材料，研究了不同温度胁迫对斜纹夜蛾耐热性和繁殖力的影响。测定了4种Hsp/Hscs（Hsp 90、Hsc 90、Hsp 70和Hsc 70）和2种蜕皮激素受体（EcRs、EcRA和EcRB 1）在不同胁迫条件下和幼虫-蛹变态过程中的mRNA水平。结果表明，轻度胁迫下的预驯化提高了成虫的耐热性，但降低了产卵量。在胁迫过程中，所有Hsp/Hsc和蜕皮激素受体基因的mRNA水平均显著上调。两种Hsp/Hsc 70和EcRs在幼虫-蛹变态过程中的表达谱相互一致。免疫共沉淀和Western blotting分析表明Hsp/Hsc 70与EcRs相互作用。Hsc 70的RNA干扰降低了E74和E75两个20 E诱导基因的mRNA水平。热休克蛋白70在冷胁迫下从细胞质转移到细胞核。这些结果表明，Hsp/Hsc 70可能参与了20 E信号的调控，Hsp/Hsc 70与EcRs之间的蛋白质-蛋白质相互作用可能是调节高耐热性与生理缺陷之间的桥梁。
Heat shock protein (Hsp) and its cognate protein (Hsc) play important roles in helping insects survive extreme temperatures. However, high level of Hsp expression usually brings negative physiological effects on organisms. The mechanism of this trade-off is unclear. In this study, a lepidopteran insect, the common cutwormSpodoptera litura, was stressed at different temperatures, and the impact on both thermotolerance and fecundity was examined. The mRNA levels of fourHsp/Hscs (Hsp90,Hsc90,Hsp70andHsc70) and two ecdysone receptors (EcRs,EcRAandEcRB1) in different stresses and during the larval–pupal metamorphosis were determined. The results revealed that the pre-acclamation at mild stress increased the thermotolerance but decreased the egg production in adults. During the stress process, the mRNA levels of all the Hsp/Hsc and ecdysone receptor genes were significantly up-regulated. The twoHsp/Hsc70s andEcRs revealed consistent expression profiles with each other during the larval–pupal metamorphosis. Co-immunoprecipitation and Western blotting analysis indicated that Hsp/Hsc70 interacted with EcRs. RNAi ofHsc70decreased the mRNA levels of two 20E-induced genes such asE74BandE75. Hsp70 transferred from the cytoplasm to nucleus in response to cold stress. These data together suggest that Hsp/Hsc70 might be involved in the regulation of 20E signaling, and the protein–protein interaction between Hsp/Hsc70 and EcRs probably act as a bridge mediating the trade-off between high thermotolerance and physiological defects.