Use of gene regulatory sensors to monitor environmental pollutant levels in small mammals and birds

由于人类活动，环境中杀虫剂和二恶英类污染物的大量增加。其中一些化学物质是持久性的，并在食物链中积累，这引起了人们对中期和长期接触对人类甚至野生动物健康的重大关切。测量环境中这类污染物的经典方法是用生化方法对水源和土壤源进行取样，以评估它们的丰度。一旦确定了这些测量值，就会评估它们是否在被认为对生物“安全”的范围内。然而，主要的缺陷是，人们如何知道需要多少这些化学物质才能影响单个物种的健康？通过芳烃受体（AhR）的作用，细胞将至少部分地解毒污染物和杀虫剂，芳烃受体调节属于细胞色素P450 1A家族的外生代谢酶（包括CYP1A1和CYP1B1）。理论上，这些CYP基因表达得越多，一个特定物种就越能应对一种特定污染物的显著剂量。我的实验室开发了分子工具，通过qRT-PCR来测量细胞中CYP基因的表达。因此，我的研究计划将是测量CYP1A1和CYP1B1基因表达，这些动物生活在农业密集地区附近，也生活在农药使用最少的地区。这些物种包括（但不限于）树燕、蒙面鼩鼱、浣熊和小棕蝙蝠。我们还将监测这些动物的雌激素信号是否受到损害，并直接检测遗传毒性雌激素代谢物的存在。这个多学科研究项目旨在解决几个重要的生物/环境问题。我坚信，我们的遗传方法（结合HPLC/质谱）比传统的生化/化学方法在测量环境污染方面更加敏感和准确。因此，在评估集约化农业对野生动物和人类健康的潜在影响方面，我们的遗传工具可能证明是极其有用和具有成本效益的。

The abundance of pesticides and dioxin-like pollutants has massively increased in the environment due to human activity. Some of these chemicals are persistent and accumulate in the food chain, which raises major concerns regarding mid- and long-term exposure on human and even wildlife health. The classical way of measuring such pollutants in the environment is to sample water and soil sources by biochemical means to assess their abundance. Once these measurements are determined, it is assessed whether they are within a range that is deemed "safe" for living creatures. However the major flaw with this is that how does one know how much of these chemicals are required to affect the health of individual species? Cells will be detoxified of pollutants and pesticides, at least in part, by the action of the aryl hydrocarbon receptor (AhR), which regulates xenobiotic metabolism enzymes belonging to the cytochrome P450 1A family (including CYP1A1 and CYP1B1). In theory, the more these CYP genes are expressed, the more a particular species is dealing with a significant dose of a particular pollutant. My laboratory has developed molecular tools to measure CYP gene expression in cells by qRT-PCR. Thus, my research plan will be to measure CYP1A1 and CYP1B1 gene expression in animals that live close to regions of intense agricultural practices, and also in regions where the use of pesticides is minimal. These species will include (but not limited to) the tree swallow, the masked shrew, the raccoon, and the little brown bat. We will also monitor if estrogen signaling is compromised in these animals and directly test for the presence of genotoxic estrogen metabolites. This multidisciplinary research program aims at addressing several important biological/environmental problems. I firmly believe that our genetic approach (coupled to HPLC/mass spectrometry) is significantly more sensitive and accurate than conventional biochemical/chemical methods to measure contamination in the environment. Hence our genetic tools could prove to be extremely useful and cost effective in assessing the potential effects of intense agriculture on wildlife and human health.