Beaty B J, Black W C, Carlson J O, Clements W H, DuTeau N, Harrahy E, Nuckols J, Kenneth E, Olson K E, Rayms-Keller A
Department of Microbiology, Colorado State University, Fort Collins 80523, USA.
Environ Health Perspect. 1998 Dec;106 Suppl 6(Suppl 6):1395-407. doi: 10.1289/ehp.98106s61395.
Molecular and population genetic ecotoxicologic approaches are being developed for the utilization of arthropods as bioreporters of heavy metal mixtures in the environment. The explosion of knowledge in molecular biology, molecular genetics, and biotechnology provides an unparalleled opportunity to use arthropods as bioreporter organisms. Interspecific differences in aquatic arthropod populations have been previously demonstrated in response to heavy metal insult in the Arkansas River (AR) California Gulch Superfund site (CGSS). Population genetic analyses were conducted on the mayfly Baetis tricaudatus. Genetic polymorphisms were detected in polymerase chain reaction amplified 16S mitochondrial rDNA (a selectively neutral gene) of B tricaudatus using single-strand conformation polymorphism analysis. Genetic differences may have resulted from impediments to gene flow in the population caused by mortality arising from exposure to heavy metal mixture pollution. In laboratory studies a candidate metal-responsive mucinlike gene, which is metal and dose specific, has been identified in Chironomus tentans and other potential AR-CGSS bioreporter species. Population genetic analyses using the mucinlike gene may provide insight into the role of this selectable gene in determining the breeding structure of B. tricaudatus in the AR-CGSS and may provide mechanistic insight into determinants of aquatic arthropod response to heavy metal insult. Metal-responsive (MR) genes and regulatory sequences are being isolated, characterized, and assayed for differential gene expression in response to heavy metal mixture pollution in the AR-CGSS. Identified promoter sequences can then be engineered into previously developed MR constructs to provide sensitive in vitro assays for environmental bioreporting of heavy metal mixtures. The results of the population genetic studies are being entered into an AR geographic information system that contains substantial biological, chemical, and geophysical information. Integrated spatial, structural, and temporal analyses of these parameters will provide invaluable information concerning environmental determinants that restrict or promote gene flow in bioreporter populations.
分子和群体遗传生态毒理学方法正在被开发，用于将节肢动物用作环境中重金属混合物的生物报告物。分子生物学、分子遗传学和生物技术领域知识的爆炸式增长，为将节肢动物用作生物报告生物提供了前所未有的机会。先前已证明，阿肯色河（AR）加利福尼亚峡谷超级基金场地（CGSS）中水生节肢动物种群对重金属侵害存在种间差异。对三尾蜉蝣进行了群体遗传分析。使用单链构象多态性分析，在三尾蜉蝣聚合酶链反应扩增的16S线粒体rDNA（一个选择性中性基因）中检测到遗传多态性。遗传差异可能是由于暴露于重金属混合物污染导致的死亡率引起种群基因流动受阻所致。在实验室研究中，已在摇蚊和其他潜在的AR-CGSS生物报告物种中鉴定出一个候选的金属反应性粘蛋白样基因，该基因具有金属和剂量特异性。使用该粘蛋白样基因进行群体遗传分析，可能有助于深入了解这个可选择基因在决定AR-CGSS中三尾蜉蝣繁殖结构方面的作用，并可能为水生节肢动物对重金属侵害反应的决定因素提供机制性见解。正在分离、表征金属反应性（MR）基因和调控序列，并检测其对AR-CGSS中重金属混合物污染的差异基因表达。然后可以将鉴定出的启动子序列工程化到先前开发的MR构建体中，以提供用于重金属混合物环境生物报告的灵敏体外检测方法。群体遗传研究的结果正在输入一个包含大量生物、化学和地球物理信息的AR地理信息系统。对这些参数进行综合的空间、结构和时间分析，将提供有关限制或促进生物报告种群基因流动的环境决定因素的宝贵信息。
