National Research Council, U.S. Environmental Protection Agency , 6201 Congdon Blvd., Duluth, Minnesota 55804, United States.
Environ Sci Technol. 2014 Feb 18;48(4):2404-12. doi: 10.1021/es4040254. Epub 2014 Jan 27.
The aim of this study was to explore the utility of "omics" approaches in monitoring aquatic environments where complex, often unknown stressors make chemical-specific risk assessment untenable. We examined changes in the fathead minnow (Pimephales promelas) ovarian transcriptome following 4-day exposures conducted at three sites in Minnesota (MN, USA). Within each site, fish were exposed to water from three locations along a spatial gradient relative to a wastewater treatment plant (WWTP) discharge. After exposure, site-specific impacts on gene expression in ovaries were assessed. Using an intragradient point of comparison, biological responses specifically associated with the WWTP effluent were identified using functional enrichment analyses. Fish exposed to water from locations downstream of the effluent discharges exhibited many transcriptomic responses in common with those exposed to the effluent, indicating that effects of the discharge do not fully dissipate downstream. Functional analyses showed a range of biological pathways impacted through effluent exposure at all three sites. Several of those impacted pathways at each site could be linked to potential adverse reproductive outcomes associated with the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows, specifically signaling pathways associated with oocyte meiosis, TGF-beta signaling, gonadotropin-releasing hormone (GnRH) and epidermal growth factor receptor family (ErbB), and gene sets associated with cyclin B-1 and metalloproteinase. The utility of this approach comes from the ability to identify biological responses to pollutant exposure, particularly those that can be tied to adverse outcomes at the population level and those that identify molecular targets for future studies.
本研究旨在探讨“组学”方法在监测水生环境中的应用，在这些环境中，复杂的、通常未知的胁迫因素使得针对特定化学物质的风险评估变得不可行。我们研究了在明尼苏达州（美国）三个地点进行的为期 4 天的暴露试验中，胖头鱼（Pimephales promelas）卵巢转录组的变化。在每个地点，鱼都暴露在来自废水处理厂（WWTP）排放口的三个位置的水中。暴露后，评估了卵巢中特定于地点的基因表达变化。通过使用梯度内的比较点，使用功能富集分析确定了与 WWTP 废水排放相关的特定生物响应。暴露于废水排放口下游位置水的鱼表现出与暴露于废水中的鱼许多相同的转录组反应，这表明排放的影响不会完全在下游消散。功能分析表明，在所有三个地点，通过废水暴露影响了一系列生物学途径。在每个地点受影响的几个途径可以与与下丘脑-垂体-性腺（HPG）轴相关的女性胖头鱼潜在不良生殖结果联系起来，特别是与卵母细胞减数分裂、TGF-β信号、促性腺激素释放激素（GnRH）和表皮生长因子受体家族（ErbB）相关的信号通路，以及与细胞周期蛋白 B-1 和金属蛋白酶相关的基因集。这种方法的实用性来自于识别污染物暴露引起的生物学反应的能力，特别是那些与种群水平的不良结果有关的反应，以及那些确定未来研究分子靶点的反应。
