Dou Wei, Tian Yi, Liu Hong, Shi Yan, Smagghe Guy, Wang Jin-Jun
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China.
Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China; Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Comp Biochem Physiol B Biochem Mol Biol. 2017 Nov;213:8-16. doi: 10.1016/j.cbpb.2017.07.005. Epub 2017 Jul 21.
To explore the functions of small heat shock proteins (sHsps) in relation to thermal stress and development in Bactrocera dorsalis (Hendel), one of the most economically important pest species attacking a wide range of fruits and vegetables, six full-length cDNAs of sHsp genes (BdHsp17.7, 18.4, 20.4, 20.6, 21.6 and 23.8) were cloned, and the expression patterns in different developmental stages and tissues, as well as in response to both thermal and 20-hydroxyecdysone (20E) exposures, were examined using real time quantitative PCR. The open reading frames (ORFs) of six sHsps are 453, 489, 537, 543, 567 and 630bp in length, encoding proteins with molecular weights of 17.7, 18.4, 20.4, 20.6, 21.6 and 23.8kDa, respectively. BdHsp18.4 and BdHsp20.4 maintained lower expression levels in both eggs and larvae, whereas remarkably up-regulated after the larval-pupal transformation, suggesting that these two sHsps may be involved in metamorphosis. Significant tissue specificity exists among sHsps: the highest expression of BdHsp20.6 and BdHsp23.8 in the Malpighian tubules and ovary, respectively, versus a peak in the fat body for others. BdHsp20.4 and BdHsp20.6 were significantly up-regulated by thermal stress. In contrast, BdHsp18.4 and BdHsp23.8 reacted only to heat stress. BdHsp17.7 and BdHsp21.6 were insensitive to both heat and cold stresses. The degree of sHsps response depends on intensity of 20E treatment, i.e., dose and time. These results strongly suggest functional differentiation within the sHsp subfamily in B. dorsalis. The physiological function of sHsp members under thermal stress and normal growth remains the subjects of further investigation.
为探究小型热休克蛋白（sHsps）在桔小实蝇（Bactrocera dorsalis (Hendel)）热应激和发育过程中的功能，桔小实蝇是一种对多种水果和蔬菜造成严重经济损失的重要害虫，本研究克隆了6个sHsp基因的全长cDNA（BdHsp17.7、18.4、20.4、20.6、21.6和23.8），并利用实时定量PCR检测了它们在不同发育阶段和组织中的表达模式，以及对热应激和20-羟基蜕皮激素（20E）暴露的响应。6个sHsps的开放阅读框（ORFs）长度分别为453、489、537、543、567和630bp，分别编码分子量为17.7、18.4、20.4、20.6、21.6和23.8kDa的蛋白质。BdHsp18.4和BdHsp20.4在卵和幼虫中的表达水平较低，而在幼虫-蛹转化后显著上调，表明这两个sHsps可能参与变态发育。sHsps之间存在显著的组织特异性：BdHsp20.6和BdHsp23.8分别在马氏管和卵巢中表达最高，而其他sHsps在脂肪体中表达最高。BdHsp20.4和BdHsp20.6在热应激下显著上调。相比之下，BdHsp18.4和BdHsp23.8仅对热应激有反应。BdHsp17.7和BdHsp21.6对热应激和冷应激均不敏感。sHsps的响应程度取决于20E处理的强度，即剂量和时间。这些结果强烈表明桔小实蝇sHsp亚家族内存在功能分化。sHsp成员在热应激和正常生长条件下的生理功能仍有待进一步研究。
