滴滴涕（DDT）是一类含有机氯的杀虫剂，被列为内分泌干扰素以及可能的致癌物。中华白海豚是珠江口常年性栖息的鲸豚，处于食物链的顶端。前期研究表明，珠江口中华白海豚体内富集了高浓度的DDT，推测其可能受到较为严重的DDT威胁。目前，对于DDT在中华白海豚细胞水平的富集规律及其细胞毒性效应研究十分有限。因此，本项目以中华白海豚皮肤成纤维（ScSF）细胞为研究对象，通过DDT暴露，检测DDT及其代谢产物在细胞内、外残留水平，揭示DDT在ScSF细胞内的富集效率与转化规律。并采用免疫组化、qRT-PCR、荧光探针激光共聚焦显微镜、流式细胞仪等研究方法，从细胞和分子水平探讨线粒体信号通路在DDT诱导ScSF细胞凋亡中的作用、Bcl-2家族蛋白对线粒体凋亡通路的调控作用以及线粒体介导的凋亡途径被激活的分子机制，为中华白海豚保护以及DDT对鲸豚健康潜在风险的评估提供科学依据。

DDT is now listed as endocrine interferon and possible carcinogen. The Indo-Pacic humpback dolphin (Sousa chinensis), on top of the chain, is year-round resident in Pearl River Estuary (PRE). Previous studies have found that there were high concentration of DDT in Sousa chinensis from PRE. S. chinensis may be threatened by DDT due to the high accumulation level. However, the studies on the accumulation and metabolism of DDT in S. chinensis cells and the mechanism in apoptosis are still very limited. This project is designed to investigate the regularity of DDT accumulation and metabolism in S. chinensis skin fibroblast (ScSF), and the effect of mitochondrial pathway, and the regulation of Bcl-2 on mitochondrial pathway in apoptosis of ScSF cells, and to reveal the causes of activation and molecular mechanism of mitochondrial pathway in apoptosis of ScSF cells. The culturing technique of ScSF cells in vitro, laserscanning confocal microscope by fluorescence probe, quantitative ELISA, molecular hybridization, flow cytometry, immunohistochemistry and electron microscope are exploited. The objective of the study is to provide scientific basis for the protection of S. chinensis, and to assess the potential health risk of DDT in cetaceans.