The objective of this study was to explore the function of carboxylesterase gene in pesticide detoxification.The Lb estl and Lb est2 encoding CarE (GenBank Accession No are EU854151 and EU854152) were cloned from L.bostrychophila in the way of reverse transcriptase PCR (RT-PCR) and rapid amplification of cDNA ends (RACE).Full-length of these two genes were 2 049 and 2 525 bp,encoded 570 and 617 amino acids,the isoelectric point were 6.85 and 4.74 respectively.Phosphorylation sites were predicted and gene sequences were analyzed,both two genes contained the catalytic activity sites and conserved sequences of the insect carboxylesterase gene as a result.Cluster analysis showed that these two genes were clustered in clade F catalytic activity sites.qRT-PCR (quantitative real time PCR) was used to test the mRNA expression level of these two carboxylesterase gene among different strains,different developmental stages,and after treatment by DDVP or PH3 were also studied.Based on the results,it was concluded that Lb est1 could regulate the growth and development of insects,Lb est2 might play an important role in metabolic detoxification and degradation of exogenous substances.%为探明羧酸酯酶CarE在嗜卷书虱抗药性中的作用,本研究采用RT-PCR和RACE方法,从嗜卷书虱体内克隆获得了2条CarE基因全长序列,命名为Lb est1与Lb est2(GenBank登录号分别为EU854151与EU854152),2条基因全长为2 049和2 525 bp,编码570和617个氨基酸组成的蛋白质,理论等电点分别为6.85和4.74.2条基因均具有昆虫羧酸酯酶的催化活性位点和保守序列,并具有多个磷酸化位点.聚类分析结果表明,2条CarE基因均属于羧酸酯酶的F簇.定量分析结果表明,Lb est2在敌敌畏和磷化氢抗性品系中的表达水平均显著高于敏感品系(P＜0.05),而Lb est1在不同品系中的表达水平没有显著差异;敌敌畏和磷化氢处理均可诱导2条基因表达水平的提高;Lb est1在发育过程中表达水平逐渐降低,而Lb est2在若虫期表达水平维持不变.结果表明,Lb est1主要参与调节昆虫的生长发育,Lb est2具有降解外源性物质和代谢解毒的功能.
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