中文摘要：

应用显微与亚显微技术和琼脂糖凝胶电泳方法,研究了不同浓度Cd^2＋（0、7.25、14.50、29.00、58.00和116.00mg·L^-1）处理不同时间（24、48、72和96h）对长江华溪蟹（Sinopotamon yangtsekiense）肝胰腺细胞凋亡的影响.结果显示,29.00mg·L^-1Cd^2＋处理48h,光镜下肝胰腺细胞凋亡主要表现为染色质不规则凝聚、固缩和边集;58.00mg·L^-1Cd^2＋处理72h,细胞核碎裂,形成凋亡小体;116mg·L^-1Cd^2＋处理96h,出现坏死细胞;电镜下48h和72h处理组肝胰腺细胞呈现典型的细胞凋亡特征,与光镜检测结果一致,具体表现为核边集、核膜折叠、核裂解形成凋亡小体.琼脂糖凝胶电泳图谱中48和72h处理组出现凋亡细胞所特有的DNA梯状条带,58.00mg·L^-1Cd^2＋处理72h后条带尤为清晰.随着Cd^2＋浓度的增加和处理时间的延长,肝胰腺中凋亡细胞所占比例呈现先升后降的趋势,凋亡指数的变化表现出显著的剂量和时间效应关系.研究表明,镉能够诱导长江华溪蟹肝胰腺出现细胞凋亡.细胞凋亡的检测及凋亡指数的变化能够灵敏地反映出镉对水生动物的胁迫程度及毒性大小,可作为水生态环境镉污染的生物评估指标.

英文摘要：

The effects of cadmium on hepatopancreas apoptosis in freshwater crab Sinopotamon yangtsekiense were investigated by microscopy,transmission electron microscopy （TEM） and agarose gel electrophoresis. To confirm if apoptosis is one of the hepatopancreas cell death pathways upon cadmium （Cd^2＋ ） administration,crabs were exposed to Cd^2＋ （0,7.25,14. 50,29. 00,58. 00 and 116. 00 mg·L^-1） for 24,48,72 and 96 hours. The results of hematoxylin and eosin （HE） staining assays demonstrated that Cd2 ＋ treatment resulted in scattered nucleoli,chromatin condensation and aggregation at the periphery of the nucleons. Moreover,nuclear fragmentation,apoptotic bodies and necrosis were detected as the cells incubated with either high concentration or long - term treatment with Cd2 ＋ . Consistently,the hepatopancreas cells showed the typical morphological characteristics of apoptosis, including nuclear chromatin condensation and marinating,nuclear membrane folding and formation of apoptotic bodies by TEM. The apoptosis characteristic‘ladder’pattern on agarose gel electrophoresis was observed,especially in 72 h exposed groups. With the increase of Cd2 ＋ concentration and duration of treatment,the apoptosis index （AI） increased initially and decreased subsequently,indicating that Cd2 ＋ could induce apoptosis in hepatopancreas cells. The variation of AI could reflect different levels of cellular toxicity caused by Cd2 ＋ . Hence,AI could serve as a biomarker to identify crustaceans from heavy metal - contaminated environments.