Neuman-Lee Lorin A, Gaines Karen F, Baumgartner Kyle A, Voorhees Jaymie R, Novak James M, Mullin Stephen J
Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois 61920, USA.
Environ Toxicol. 2014 Sep;29(9):1072-82. doi: 10.1002/tox.21837. Epub 2013 Feb 23.
Ecotoxicological studies that focus on a single endpoint might not accurately and completely represent the true ecological effects of a contaminant. Exposure to atrazine, a widely used herbicide, disrupts endocrine function and sexual development in amphibians, but studies involving live-bearing reptiles are lacking. This study tracks several effects of atrazine ingestion from female Northern Watersnakes (Nerodia sipedon) to their offspring exposed in utero. Twenty-five gravid N. sipedon were fed fish dosed with one of the four levels of atrazine (0, 2, 20, or 200 ppb) twice weekly for the entirety of their gestation period. Endpoints for the mothers included blood estradiol levels measured weekly and survival more than 3 months. Endpoints for the offspring included morphometrics, clutch sex ratio, stillbirth, and asymmetry of dorsal scales and jaw length. Through these multiple endpoints, we show that atrazine ingestion can disrupt estradiol production in mothers, increase the likelihood of mortality from infection, alter clutch sex ratio, cause a higher proportion of stillborn offspring, and affect scale symmetry. We emphasize the need for additional research involving other reptile species using multiple endpoints to determine the full range of impacts of contaminant exposure.
专注于单一终点的生态毒理学研究可能无法准确、全面地反映污染物的真实生态效应。阿特拉津是一种广泛使用的除草剂，接触它会扰乱两栖动物的内分泌功能和性发育，但缺乏涉及胎生爬行动物的研究。本研究追踪了雌性北水蛇（Nerodia sipedon）摄入阿特拉津后对其子宫内暴露的后代产生的多种影响。25条怀孕的北水蛇在整个妊娠期每周两次被喂食添加了四种阿特拉津水平（0、2、20或200 ppb）之一的鱼。母亲的终点指标包括每周测量的血液雌二醇水平和存活超过3个月。后代的终点指标包括形态测量、窝卵性别比、死产以及背鳞不对称和颌长。通过这些多个终点指标，我们表明摄入阿特拉津会扰乱母亲体内雌二醇的产生，增加感染导致死亡的可能性，改变窝卵性别比，导致更高比例的死产后代，并影响鳞片对称性。我们强调需要使用多个终点指标对其他爬行动物物种进行更多研究，以确定污染物暴露的全部影响范围。
