多环麝香污染胁迫对蚯蚓特异性蛋白基因表达的影响

Polycyclic Musks Exposure Affects Gene Expression of Specific Proteins in Earthworm Eisenia fetida

为了探讨蚯蚓特异性蛋白基因表达在监测多环麝香低水平长期暴露污染中的应用,选择蚯蚓热休克蛋白(HSP70)、钙网蛋白(CRT)、亲环素A(cyPA)、翻译控制肿瘤蛋白(TCTP)等代表性蛋白基因作为供试基因.采用自然土壤污染模拟实验,基于mRNA表达分子水平,研究吐纳麝香(AHTN)与佳乐麝香(HHCB)长期(28 d)污染胁迫对以上各特异性蛋白基因响应表达的影响.通过序列同源性比较与荧光定量PCR熔解曲线结果分析,表明设计的引物适合供试基因mRNA表达水平的检测.染毒暴露28 d后,当AHTN染毒浓度小于30μg.g-1或HHCB浓度小于50μg.g-1时,蚯蚓HSP70基因表达水平无显著变化,而AHTN浓度等于或大于30μg.g-1和HHCB浓度等于或大于50μg.g-1时,HSP70基因表达水平呈显著下调趋势;而各AHTN或HHCB浓度处理组中蚯蚓CRT基因显著上调表达;cyPA和TCTP基因表达水平与对照组比较均无呈现显著性差异.研究结果表明,HSP70与CRT等基因的响应表达有望成为表征多环麝香土壤污染暴露水平及生态毒理效应的潜在生物标志物.

To investigate the changes in gene expression of earthworm specific proteins following long-term exposure to low-dose polycyclic musks in soil,the mRNA expression levels of the four representative protein-coding genes（HSP70,CRT,cyPA,TCTP） were examined in earthworm Eisenia fetida exposed to polycyclic musks using real-time quantitative PCR（RT-qPCR）.The purpose of this study was to investigate mRNA expression profiles of test protein genes in response to sublethal galaxolide（HHCB） and tonalide（AHTN） for 28 d exposure.The analysis results of both sequence alignment and melting curves of RT-qPCR reactions showed that the selected primers were appropriately qualified for quantitative mRNA analysis.mRNA expressions of HSP70 gene were not significantly changed in Eisenia fetida exposed to low concentrations of AHTN（less than 30 μg·g^-1） and HHCB（less than 50 μg·g^-1）.But HSP70 gene expressions were significantly down-regulated at concentrations of AHTN or HHCB equal to or greater than 30 or 50 μg·g^-1.However,up-regulation of CRT gene expressions was induced in response to all test concentrations of AHTN and HHCB.Both cyPA and TCTP gene expressions were not varied compared to control groups after 28 days of exposure.Overall,the results indicated that HSP70 and CRT genes expression patterns might be potential early molecular biomarkers for predicting the harmful exposure level and ecotoxicological effects of polycyclic musks contaminated soil.