亚致死剂量马拉硫磷和西维因对飞蝗P450基因表达研究

采用实时定量PCR技术检测飞蝗Locusta migratoria细胞色素P450基因CYP4G62、CYP6EL1和CYP9AQ1经马拉硫磷和西维因不同亚致死剂量和不同时间处理后mRNA的表达水平。结果表明,经马拉硫磷不同亚致死剂量LD10、LD30和LD50处理后,飞蝗CYP4G62和CYP6EL1均在高剂量LD50被显著诱导,分别为对照的3.03和2.0倍,而在低剂量LD10无显著性差异。CYP9AQ1在3个亚致死剂量下表达量均显著提高,且增量随处理浓度增加而降低。经西维因3个亚致死剂量处理后,除在LD30这一浓度下引起CYP4G62表达提高外,其它的P450基因均无显著性差异。选择2种农药的LD15对飞蝗进行点滴处理,分别检测6、12、24和48 h基因的相对表达。经马拉硫磷LD15处理后,除CYP6EL1在12 h和CYP9AQ1在24 h表达量显著降低外,其它各时间点基因表达均无显著差异。经西维因处理不同时间后,3个P450基因的相对表达量均无显著性差异。综合上述结果说明马拉硫磷对3个细胞色素P450基因有一定的诱导作用,而西维因对其无诱导作用。

Effect of sublethal doses of malathion and carbaryl on the P450 genes of Locusta migratoria

Two insecticides containing malathion and carbaryl were used to evaluate the possible effects of these compounds on the expression of CYP4G62, CYP6EL1 and CYP9AQ1 in Locusta migratoria as assessed by Real time PCR. LDsodoses of both insecticides significantly increased the expression of CYP4G62 and CYP6EL1 compared to the control, but there was no significantly difference between treatments and control at LD10 doses. Exposure of insects to three, sublethal, pesticide doses was followed by a significant, dose dependent increase in the relative expression of cYPgAQ1, but the increase in gene expression decreased with increasing pesticide concentration. Treatment with carbaryl only increased the relative expression of CYP4G62 at LD30, but had no effect on the other P450 genes. LD15 was selected for a time effect experiment in which relative gene expression was measured at 6 , 12 , 24 and 48 h. After treatment with malathion at LD15, the relative expressions of CYP6EL1 and CYP9AQ1 were significantly reduced at 12 and 24 h, whereas there was no change in the expression of CYP4G62. The relative expression of all three genes was unaffected by different duration of exposure to earbaryl. The results indicate that malathion, but not carbaryl, may stimulate the relative expression of all three P450 genes.