Freeman Jennifer L, Rayburn A Lane
Department of Crop Sciences, 320 ERML, 1201 West Gregory Drive, University of Illinois, Urbana, Illinois 61801, USA.
Environ Toxicol Chem. 2005 Jul;24(7):1648-53. doi: 10.1897/04-338r.1.
Atrazine is one of the major surface water contaminants in the midwestern United States. Speculations have arisen on the potential effects of atrazine contamination to anuran larvae developing in these surface waters. In this study, Xenopus laevis tadpoles were exposed to environmentally relevant concentrations of atrazine. Nuclear and morphological endpoints were used to assess the effects of atrazine on developing X. laevis. Atrazine significantly affected metamorphing X. laevis after three-weeks exposure compared to controls as revealed by flow cytometric nuclear DNA analysis. The flow cytometric analysis was reflective of developmental effects. The number of nuclei per organism also was analyzed. Nuclei number was found to be associated with X. laevis development. Nuclei counting showed significant effects of atrazine after five-weeks exposure. A third endpoint, Nieuwkoop and Faber (NF) morphological staging, also demonstrated that atrazine significantly affected development after four weeks. Atrazine was found to alter the timing of metamorphosis of X. laevis using both nuclear analysis and gross morphology. The NF staging was found to be a sensitive assay to measure effects of development, whereas flow cytometry provided an impartial quantitative measure.
阿特拉津是美国中西部地区主要的地表水污染物质之一。关于阿特拉津污染对在这些地表水中发育的无尾两栖类幼体的潜在影响，已经出现了各种猜测。在本研究中，将非洲爪蟾蝌蚪暴露于与环境相关浓度的阿特拉津中。利用细胞核和形态学指标来评估阿特拉津对发育中的非洲爪蟾的影响。流式细胞术核DNA分析显示，与对照组相比，暴露三周后，阿特拉津对正在变态的非洲爪蟾有显著影响。流式细胞术分析反映了发育效应。还分析了每个生物体的细胞核数量。发现细胞核数量与非洲爪蟾的发育有关。细胞核计数显示，暴露五周后，阿特拉津有显著影响。第三个指标，即Nieuwkoop和Faber（NF）形态学分期，也表明四周后阿特拉津对发育有显著影响。利用细胞核分析和大体形态学方法均发现，阿特拉津会改变非洲爪蟾的变态时间。发现NF分期是一种测量发育效应的灵敏检测方法，而流式细胞术提供了一种客观的定量测量方法。
