【目的】基于橘小实蝇（Bactrocera dorsalis）转录组数据，系统分析橘小实蝇幼虫解毒代谢酶系基因在受到高效氯氰菊酯持续胁迫时的表达模式，鉴定其中起主要作用的基因，并探讨这些基因组织差异表达的生物学意义。【方法】利用qPCR技术检测橘小实蝇幼虫受到高效氯氰菊酯持续胁迫后，30个解毒代谢酶系（GSTs、P450s、CCEs）基因在整虫、中肠以及脂肪体的表达水平变化情况。【结果】在高效氯氰菊酯持续胁迫作用下，橘小实蝇8个GSTs基因中，其mRNA表达量出现明显上调的主要是Delta家族的4个基因，它们在中肠和脂肪体均出现了5.6—32.5倍的过量表达，而其他家族的GSTs基因经高效氯氰菊酯胁迫后没有出现明显的应激反应。同时， Delta家族的GSTs基因虽然在中肠和脂肪体对药剂胁迫有积极的响应，但是它们的表达在整虫却没有明显的变化。6个CCEs基因在整虫中出现一定程度的上调，其中α-E3基因的表达量上调了4.1倍，但是这些基因在中肠和脂肪体均没有出现上调的情况。16个P450s基因的定量分析结果表明，有多个P450s基因的mRNA的表达出现了上调，且大部分基因属于CYP4和CYP6两个家族。其中，CYP4家族中出现明显上调反应的主要有CYP4D47（中肠）、CYP4E9（整虫、脂肪体）和CYP4P5（整虫、脂肪体）。CYP4AD1的表达量在中肠和脂肪体均有一定程度的上调，而在整虫中没有变化。另外，CYP4S18和CYP4AC4没有出现应激表达或者表达量的变化不明显。CYP6家族中，CYP6A48和CYP6A41在脂肪体的表达量显著上调，分别提高了18.0和9.6倍，CYP6G6和CYP6A50在脂肪体的表达量也有一定程度的上升，而CYP6EK1的表达量虽然在整虫提高了4.8倍，但是在中肠和脂肪体并没有明显的变化。其他家族的P450s基因，如CYP12C2、CYP9F6、CYP12N1和CYP309B1等基因的表达量经高效氯氰菊酯胁迫后在脂肪体中也出现了显著的上调，而CYP317B1的表达量在药剂压力下并没有明显的变化。【结论】橘小实蝇幼虫在应对高效氯氰菊酯胁迫时，体内的解毒代谢酶系基因集中在中肠和脂肪体高水平表达，但存在整体保持平衡的现象，推测橘小实蝇在应对杀虫剂的持续胁迫时，存在趋于平衡的能量分配策略，即通过提高能量的利用效率，减少在抵御外源杀虫剂伤害时额外能量的消耗。这种可以避免出现适合度代价的策略可能是昆虫应对环境压力的一种重要适应机制。%Objective]Based on the transcriptome data ofBactrocera dorsalis, the aim of this study is to systematically analyze the expression of genes in larvae encoding detoxification enzymes underβ-cypermethrin exposure, identify important detoxification genes, and focus on the discussion of biological significance of tissue specific expression of these genes.[Method] The expressions of 30 detoxification genes in the whole body of larvae, midgut, and fat body were detected underβ-cypermethrin exposure by using qPCR.[Result]Under the stress ofβ-cypermethrin, the qPCR results of 8 GSTs genes showed that the mRNA levels of 4 Delta class genes significantly increased. The expressions of genes from Delta class were up-regulated to 5.6-32.5 folds in the midgut and fat body, but the expressions of other GST genes did not show very active reaction when exposed toβ-cypermethrin. Meanwhile, although the expressions of Delta class GSTs genes significantly increased in midgut and fat body, the expression changes of these genes were not so apparent in the whole body. As for the 6 CCEs genes, their expressions were up-regulated in some degree in the whole body, andα-E3 was up-regulated to 4.1 folds. However, in the midgut and fat body, the expressions of these genes did not increase significantly. The qPCR results of 16 P450s genes showed that the expressions of most P450s genes were up-regulated, especially the genes from CYP4 and CYP6 families. In CYP4 family, the expressions ofCYP4D47 (midgut),CYP4E9(whole body and fat body), CYP4P5(whole body and fat body) were highly up-regulated. The expression ofCYP4AD1 increased in some degree in the midgut and fat body, but no significant changes were found in the whole body.CYP4S18andCYP4AC4 did not show any positive reaction or their expression changes were not apparent. In CYP6 family, the expressions ofCYP6A48 andCYP6A41 had a significant increase in the fat body, 18.0 and 9.6 folds up-regulated, respectively. The expression of others likeCYP6G6 and CYP6A50also increased. The expression ofCYP6EK1was up-regulated by 4.8 folds in the whole body, but did not change in midgut and fat body. The expressions of the other genes, such asCYP12C2,CYP12N1,CYP9F6, andCYP309B1 also significantly increased in the fat body when exposed toβ-cypermethrin. But the expression ofCYP317B1 did not change under the stress.[Conclusion]When under the stress ofβ-cypermethrin, the detoxification genes inB. dorsalis larvae were highly enriched in midgut and fat body, but showed a balance in the whole body. It suggests that when under the toxic stress, the pests may have special strategy for efficient use and proper distribution of energy, which increase the energy efficiency to decrease the extra energy cost to resist the damage of exogenous toxin. This kind of strategy might be an important acclimation of insects to avoid fitness cost when under the environmental pressures.
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