PBDEs对海洋浮游动物生殖机能的毒性效应及基于钙离子信号通路的生殖毒性机制研究

Marine zooplankton is suggested to be the beginning and the key loop of bioaccumulation and biotrasportation of Polybrominated diphenyl ethers(PBDEs), the new type of persistent organic pollutants（POPs） in marine food web. It's of great significance to elucidate the toxic effects of PBDEs on marine zooplankton in order to keep the equilibrium and sustainability of marine ecosystem. Productive toxicity is chosen as the key question of the present studies and the aims are to address the following questions: (1) Are PBDEs have productive toxicities on marine zooplankton? (2)What's the possibly effective pathway and mechanisms? (3)Does the productive toxicity pass from paternal generation to filial one? In order to answer these questions,the experimentally ecological toxic experiments are carried out under controlled laboratory conditions. Two typical kinds of PBDEs:BDE47 and BDE209 are used as the stressors and two model organisms of marine zooplankton: copepod and rotifer are selected as the target ones, and the main research contents include:(1) Basing on the integrated biology theory, the productive toxicities are essayed from multi-pathway and from multi-biospectrum of population, individual, tissue and cell, and molecular. Parameters closely relating to productive ability such as dynamics of pululation structure,eggs production, diaopause eggs and the damages on productive glands and DNA from sub-cellular and molecular views are analyzed;（2）The possible pathway and mechanism on productive toxicity are estimated basing on the theory of calcium signaling pathway,that is Ca2+-CaM-CaMKⅡ pathway. Different sites of the signaling pathway are anzlyzed respectively, which include: calcium homeostasis, calcium signals (the expression of CaM and CaMKⅡ) and two phases of immune responses at the downstream of the pathway: the first phase of cytochrome P450 (CYP450) and the second phase of Glutathione S-transferases (GSTs). Moreover, the relations between the changes of calcium signaling pathway and the immune responses exposed to different stress conditions are analyzed. (3) Technique of GC/MS is applied to analyze the concentration differentiations of the pollutants in the productive glands of paternal and filial generations and the purpose is to bring light on weather productive toxicity induced by PBDES could go down from one generation to the following one. If it is, to what extent would the toxicity be exerted on the offsprings. The present study would provide the basic data and theory for further studies on the potential hazards of PBDEs on marine ecosystem.

海洋浮游动物是新型持久性有机污染物多溴联苯醚(PBDEs)在海洋中食物链中富集和传递的起点，阐明PBDEs对海洋浮游动物群落的影响对维持海洋生态系统的平衡和稳定具有重要意义。本研究拟以PBDEs对海洋浮游动物的生殖毒性为切入点，开展以下研究：(1)基于整合生物学理念，从种群、个体、组织、细胞和分子等不同生物组织层次入手，多途径综合分析PBDEs对海洋浮游动物生殖机能的毒性效应；(2)研究PBDEs胁迫对Ca2+-CaM-CaMKⅡ信号通路的影响，通过对钙离子动态平衡、钙离子信号变化以及钙离子信号通路下游两个阶段的应激响应变化等多个作用位点的分析，系统研究PBDEs生殖毒性的作用途径及机理；(3)分析PBDEs在亲代和子代中的蓄积差异，阐明PBDEs生殖毒性的传代效应。研究结果将为进一步阐明PBDEs的海洋生态学效应提供基础的理论和实验依据。

海洋浮游动物是新型持久性有机污染物多溴联苯醚(PBDEs)在海洋中食物链中富集和传递的起点，研究PBDEs对海洋浮游动物的生殖毒性将对维持海洋生态系统的平衡和稳定具有重要意义。本项目在实验生态条件下从种群、个体、组织和细胞和分子等不同生物组织层次入手，多层次、定量分析PBDEs对海洋浮游动物生殖机能的毒性效应与作用机理，取得如下研究成果：.1、研究PBDEs对褶皱臂尾轮虫的生殖毒性，阐明褶皱臂尾轮虫对PBDEs的生殖响应策略。PBDEs影响褶皱臂尾轮虫种群的动态变化，缩短生殖周期，降低特定年龄存活率，产生明显的发育毒性。卵巢结构与功能受到损伤，卵黄腺皱缩、细胞核变形；每雌体产卵个数与种群的产卵率降低，生殖价随胁迫浓度的增高而不断降低。上述结果均说明PBDEs具有显著的生殖毒性。PBDEs胁迫改变目标生物的生殖过程，抑制无性生殖、激活有性生殖，产生从无性生殖向有性生殖转变的策略性响应。本研究首次建立了ROS荧光探针DCFH-DA和Ca2+荧光探针Fluo-3/AM在海洋浮游动物中的负载技术，提高了研究的可行性。.2、分析ROS与Ca2+介导的信号通路在PBDEs诱导的浮游动物生殖毒性中的作用，提出可能的胁迫响应途径与机理。主要回答了两个问题：ROS是生殖毒性的“因”还是“果”？ PBDEs诱导的细胞凋亡途径是怎样的？研究从Ca2+的动态平衡入手分析PBDEs对[Ca2+]in和CaM的变化；从ROS和抗氧化系统的应激响应入手分析I、Ⅱ相解毒酶活性的变化，研究ASA-GSH通路、MAPKs信号通路变化对PBDEs的响应，提出“ROS诱导的氧化胁迫及由此导致的抗氧化系统I、II相酶的顺序性响应是PBDEs毒性产生的可能途径及作用机理之一”的论断；研究ROS、[Ca2+]in信号变化与细胞凋亡的相关性，明确线粒体途径参与了PBDEs诱导的生殖细胞凋亡过程。这也是首次在海洋浮游动物中开展Ca2+信号通道研究。.3、分析目标污染物在水体与目标生物中的蓄积差异。.基于上述研究结果，共发表学术论文14篇，授权受理专利4项，获省部级奖项1项。