食物相硒是动物摄取硒的主要途径，硒进入生物体后可拮抗镉的毒性，这对镉污染环境下生物生存具有重要意义。硒或镉在亲代生物体内蓄积后，随着繁殖过程均可单独通过卵黄蛋白原进入到受精卵，并传递到子代体内。而目前有关硒-镉母体共传递动态过程及其对胚胎和幼鱼发育的生物效应还鲜有研究，其内在机制尚不清楚。针对这一问题，本项目在前期研究基础上，以模式生物日本青鳉鱼为研究对象，拟开展食物相硒拮抗镉毒性和硒-镉母体共传递效应及机制研究。研究从硒-镉蓄积、组织及亚细胞分布等方面来揭示硒对镉拮抗的过程与机理；从主要功能性蛋白（硒蛋白、金属硫蛋白和卵黄蛋白原等）及其基因水平变化、DNA损伤、氧化应激及生长发育繁殖等方面，深入解析硒对镉拮抗与硒-镉母体共传递的生物效应及内在机理。研究结果能深入揭示硒对镉拮抗和母体共传递过程及机制，为二者生物互作提供理论支撑，为硒的合理利用及其生物功能评价提供科学依据。

Dietary exposure route is the predominant route for the bioaccumulation of Se in animals. The antagonism of Se against Cd may be beneficial for the survival of organisms inhabiting in Cd-contaminated environments. The Se and Cd accumulated in the parental generation can be transferred to fertilized eggs and offspring via vitellogenin (i.e., maternal transfer). However, the effects and underlying mechanisms of the co-maternal transfer of Se and Cd in embryonic and larval fish have been rarely studied. Based on our earlier studies, the proposed work use Japanese medaka (Oryzias latipes) as a model organism to explore the protection of Se against Cd toxicity. The aims of this proposed work are to study the Se-Cd antagonism and underlying mechanisms, and to determine the dynamics of their co-maternal transfer in O. latipes. The Se-Cd antagonism is evaluated through the bioaccumulation, tissue and subcellular distribution. The effects and mechanisms of Se-Cd antagonism and co-maternal transfer will be examined, mainly focusing on the crucial functional proteins (e.g., selenoprotein, metallothionein, and vitellogenin etc.) at their transcriptional level, DNA damage, oxidative stress, and growth and reproduction. This research will provide not only deeper insights on the antagonistic effects of Se on Cd, the co-maternal transfer of Se-Cd in aquatic organisms, but technical support for the appropriate use of Se in animal nutrition and evaluation of the biological functions of Se in animals as well.