Lee Soon-Mi, Lee Se-Bum, Park Chul-Hwi, Choi Jinhee
Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, South Korea.
Chemosphere. 2006 Nov;65(6):1074-81. doi: 10.1016/j.chemosphere.2006.02.042. Epub 2006 Apr 19.
To identify a sensitive biomarker of freshwater monitoring, we evaluated pollutant-induced expression of heat shock proteins (HSPs) and hemoglobins (Hbs) genes in the larvae of the aquatic midge Chironomus tentans (Diptera, Chironomidae). As pollutants, we examined nonylphenol, bisphenol-A, 17alpha-ethynyl estradiol, bis(2-ethylhexyl) phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride. We also investigated larval growth as a physiological descriptor by measuring changes in the body fresh weight and dry weight after chemical exposure. The response of the HSPs gene expression by chemical exposure was rapid and sensitive to low chemical concentrations but it was not stressor specific. Interestingly, an increase in the expression of HSPs genes was observed not only in a stress inducible form (HSP70), but also in a constitutively (HSC70) expressed form. The expression of Hb genes showed chemical-specific responses: that is, alkyl phenolic compounds increased the expression of hemoglobin genes, whereas pesticides decreased the expression. As expected, molecular-level markers were more sensitive than physiological endpoints, suggesting that gene expression could be developed as an early warning biomarker in this animal. The overall results suggest that the expression of HSP and Hb genes in Chironomus could give useful information for diagnosing general health conditions in fresh water ecosystem. The expression of Hb genes, in particular, seems to be a promising biomarker, especially in view of the potential of Chironomus larvae as a biomonitoring species and of the physiological particularities of their respiratory pigments.
为了确定淡水监测的敏感生物标志物，我们评估了污染物诱导水生摇蚊（双翅目，摇蚊科）幼虫中热休克蛋白（HSPs）和血红蛋白（Hbs）基因的表达。作为污染物，我们检测了壬基酚、双酚A、17α-乙炔基雌二醇、邻苯二甲酸二（2-乙基己基）酯、硫丹、百草枯二氯化物、毒死蜱、杀螟硫磷、氯化镉、硝酸铅、重铬酸钾、苯并[a]芘和四氯化碳。我们还通过测量化学暴露后幼虫的鲜重和干重变化，将幼虫生长作为一种生理指标进行了研究。化学暴露对HSPs基因表达的影响迅速且对低化学浓度敏感，但不具有应激源特异性。有趣的是，不仅在应激诱导型（HSP70）中观察到HSPs基因表达增加，在组成型（HSC70）表达形式中也观察到了增加。Hb基因的表达表现出化学特异性反应：即烷基酚化合物增加了血红蛋白基因的表达，而农药则降低了表达。正如预期的那样，分子水平的标志物比生理终点更敏感，这表明基因表达可以作为这种动物的早期预警生物标志物来开发。总体结果表明，摇蚊中HSP和Hb基因的表达可为诊断淡水生态系统的总体健康状况提供有用信息。特别是Hb基因的表达似乎是一种有前景的生物标志物，尤其是考虑到摇蚊幼虫作为生物监测物种的潜力及其呼吸色素的生理特性。
