中文摘要：

为了探讨镉对长江华溪蟹（Sinopotamon yangtsekiense）的毒性机理，应用mRNA差异显示技术，对4种浓度镉（Cd：5，0．5，0．05，0．005mg／L）胁迫下的华溪蟹心脏组织的基因表达差异进行了比较．结果显示，镉处理前后基因表达在数量水平和质量水平上都存在显著差异，数量水平的差异表现为镉胁迫过程中表达序列标签（ESTs）增强表达或减弱表达，质量水平上的差异表现为镉胁迫使部分ESTs特异诱导表达或沉默表达．12对引物组合共获得246条扩增条带，其中有190条为共有条带，占总条带数的77．2％．差异表达的片段有56条，占总条带数的22．7％．本研究已初步筛选并获得了一些重复性较好的差异条带．

英文摘要：

To investigate the ability of Cd to affect gene transcription,mRNA differential display technique was used to compare with the different expression sequences in the freshwater crab （Sinopotamon yangtsekiense） exposed to different doses of cadmium salt （5,0. 5,0.05,0. 005 mg/L） for 24 h. The analysis of the differences in gene expression during Cd stress indicated that the gene expression was obviously altered both in quantity and quality. Quantitatively, there were enhanced or depressed expressions of genes during Cd stress with genetic expression trend forwards the control. Qualitatively,the freshwater crab could have specific gene expression or silent expression induced by Cd stress. 12 kinds of primer subsets amplified 246 clear bands of cDNA fragment. Moreover, the number of differential expressed cDNA fragment is 56 （22.7%） ;both the normal and Cd-treated heart coincident expression 190 （77.2%） bands. These results could be used in analysis the toxicity of cadmium-induced mechanism of crustaceans on molecular level for aquaculture, environmental monitoring and others to offer theoretical basis.