Toxic assessment of environmental contaminant chemicals using DNA microarrray

我们进行了基因表达的筛选暴露于环境污染物的化学品，以检测对这些化学品的生物反应。本研究利用基因芯片技术研究了低剂量甲基汞暴露对围产期基因表达的影响。甲基汞进入水生食物链，成为人类饮食中汞的主要来源。在食肉鱼类和海洋哺乳动物体内发现的甲基汞含量最高。由于暴露水平较低，有必要考虑各种混杂因素。本研究以多氯联苯（PCBs）为混杂因子，探讨甲基汞和PCBs联合暴露对健康人群的影响。由于人类甲基汞暴露的主要来源是鱼类，具有强烈神经毒性的生物浓缩多氯联苯暴露也会发生。本研究利用DNA微阵列技术，研究了围产期甲基汞暴露组、多氯联苯暴露组、甲基汞和多氯联苯联合暴露组小鼠脑组织基因表达的变化。我们将从暴露动物脑中提取的总RNA样品应用于DNA微阵列。然后根据生物信息学方法对大量数据进行了分析。我们对表达基因的类别进行了分类，并将基因表达谱分为三组：MeHg暴露组、PCB暴露组、MeHg-PCB联合暴露组。

We conducted the screening of gene expression under exposures of environmental contaminant chemicals in order to detect biological response against these chemicals. This study deals with gene expression against methylmercury exposure, especially low-dose, perinatal periods using DNA microarray.Methylmercury is known as neurotoxicant especially in the development period. MeHg enters the aquatic food chain to become the predominant dietary source of mercury in humans. The highest levels of MeHg are found in predatory fish and sea mammals. As the exposure level is low, it is necessary to consider the various confounding factors. In this study, we choose the polychlorinated biphenyls (PCBs) as confounding factor, and investigated the effect of combined exposure to methylmercury and PCBs. Because main sources of human methylmercury exposure are fish, bioconcentrated PCBs exposure which have strong neurotoxicity also occurs. These chemicals are ingested mainly through fish consumption, but little is known about the hazardous effects.In this study, we investigated the gene expression on mouse brain of the MeHg exposed group, the PCBs exposed group, or, co-exposure to MeHg and PCBs during perinatal periods using DNA microarray technique. We applied extracted total RNA sample from brain of exposed animals to the DNA microarray. Then we carried out analysis of plenty of data according to bioinformatics methodologies. We classified the categories of expression genes and characterizing the gene expression profiling under the tree groups ; MeHg exposure group, PCB exposure group, MeHg-PCB co-exposure group.