噻虫嗪对意大利蜜蜂6种CYP6AS基因表达的影响

Effects of thiamethoxam on expression of cytochrome P6AS genes, in honeybees (Apis mellifera ligustica)

细胞色素P450单氧酶(cytochrome P450 monooxygenase,CYP)是昆虫体内重要的解毒酶。 CYP 6 AS 亚家族基因特异性的存在于膜翅目昆虫中,一些特异性的 CYP 6 AS 基因已经被证实参与到蜜蜂对某些外源物质和杀虫剂的解毒和代谢过程中。本研究主要探测了亚致死浓度噻虫嗪对意大利蜜蜂 Apis mellifera ligustica CYP单氧酶活性及 CYP 6 AS 亚家族基因表达水平的影响。首先测定了噻虫嗪LC 10 和LC 5 经口处理4日龄意大利蜜蜂后48 h CYP酶活性,然后应用荧光定量PCR技术检测了6种 CYP 6 AS 基因( CYP6AS3 ,CYP6AS4,CYP6AS5,CYP6AS10,CYP6AS14 和 CYP6AS15 )表达变化情况。结果表明,噻虫嗪LC 10 和LC 5 处理后,意大利蜜蜂CYP酶活性均极显著增加( P <0.01)。噻虫嗪LC 10 和LC 5 处理对意大利蜜蜂 CYP6AS4 ,CYP6AS10 和 CYP6AS15 基因表达没有显著影响;LC 10 和LC 5 处理后 CYP6AS3 基因表达量显著增加( P <0.05);LC 10 处理能够显著诱导 CYP6AS5 基因上调表达( P <0.05);而LC 10 和LC 5 处理极显著抑制 CYP6AS14 基因的表达( P <0.01)。这为进一步探究蜜蜂对噻虫嗪的解毒机制提供了新的线索。

Cytochrome P450 monooxygenase (CYP) is an important detoxifying enzyme in insect.The CYP 6 AS subfamily are unique to hymenopterans,and several CYP 6 AS genes have been implicated in detoxification and metabolism of xenobiotics and insecticides in honeybees.This study aims to investigate sublethal effects of thiamethoxam on CYP activity,and expression of six CYP 6 AS genes,in honeybees ( Apis mellifera ligustica ).We firstly tested the activity of CYP in 4-day-old honeybees oral treated with LC 10 and LC 25 of thiamethoxam at 48 h.Then the expression levels of six CYP 6 AS genes ( CYP6AS3 ,CYP6AS4 ,CYP6AS5 ,CYP6AS10 ,CYP6AS14 and CYP6AS15 ) were measured by RT-qPCR.The activity of CYP was significantly increased with both LC 10 and LC 5 of thiamethoxam ( P <0.01).There was no significant difference in CYP6AS4 ,CYP6AS10 and CYP6AS15 expression compared with the control.However,the expression level of CYP6AS3 was significantly increased by LC 10 and LC 5 of thiamethoxam ( P <0.05),and the expression level of CYP6AS5 was up-regulated by LC 10 of thiamethoxam ( P <0.05).While,the expression level of CYP6AS14 was distinctly inhibited by LC 10 and LC 5 of thiamethoxam ( P <0.01).Our findings provided important information for exploring the detoxication mechanisms of honeybees to thiamethoxam.