In Vivo Cellular and Molecular Imaging Centers (ICMICs)

该建议的重点是早期和晚期胚胎在胚胎发育方面对遗传毒物的敏感性差异。草虾将被用作模型 生物体的特点的早期和晚期胚胎的敏感性的差异，污染物诱导的DNA损伤。草虾胚胎已被用于毒性测试。成年草虾将暴露于含有铬，汞，或多环芳烃（PAH？s）的情况。将在各个发育阶段跟踪对照和遗传毒性暴露成虫产生的胚胎阶段。将使用彗星试验测量DNA链断裂和修复，包括对特定病变和交联定量的修改。DNA修复酶将被扩增、克隆和测序。根据该序列，将制备引物并进行测试，以开始研究DNA修复基因在早期和晚期胚胎中的表达。这项工作的意义在于，它提供了 遗传毒性研究的模型。通过研究草虾胚胎，草虾胚胎已经充分研究了发育过程，在实验室中容易操纵的快速繁殖周期，并且经常暴露于污染环境中的遗传毒物，我们可以了解使早期胚胎阶段对污染物更敏感的过程。

This proposal focuses on differences in the susceptibility to genotoxicants of early and late stage embryos with respect to embryological development. Grass shrimp will be used as a model organism to characterize the difference in susceptibility of early and late stage embryos to contaminant induced DNA damage. Grass shrimp embryos have been used for toxicity testing. Adult grass shrimp will be exposed to sediments and food containing chromium, mercury, or polycyclic aromatic hydrocarbons (PAH?s). Embryo stages produced from control and genotoxicant exposed adults will be followed through the various stages of development. DNA strand breakage and repair will be measured using the comet assay, including modifications for quantification of specific lesions and crosslinks. A DNA repair enzyme will be amplified, cloned and sequenced. Based on this sequence, primers will be prepared and tested to begin studies on the expressi on of a DNA repair gene in early and late stage embryos. The significance of this work is that it provides a model for the study of genotoxicity. By working with grass shrimp embryos, which have well studied developmental processes, a quick reproductive cycle which is easily manipulated in the laboratory, and are routinely exposed to genotoxicants in contaminated environments, we can understand the processes which make early embryonic stages more sensitive to contaminants.