为探讨氯化汞( HgCl₂)对大鲵皮肤CATH-BF基因及心脏和胰腺CATH-2、CATH-3基因表达的影响，将幼龄中国大鲵分别暴露于0 (对照)、1、10、100 ng/L HgCl₂ 中24、48、72 h，采用实时定量RT-PCR方法分析HgCl₂处理不同时间后，大鲵皮肤CATH-BF、心脏和胰腺中CATH-2、CATH-3基因的表达情况。结果显示，与对照组相比，大鲵暴露于HgCl₂ 24 h后，大鲵皮肤CATH-BF基因表达水平均呈现下降变化趋势，即1、100 ng/L HgCl₂对大鲵暴露24 h极显著下调了大鲵皮肤CATH-BF基因表达水平(P<0.01)，10 ng/L HgCl₂对大鲵暴露24 h显著下调了大鲵皮肤CATH-BF基因表达水平(P<0.05)，10、100 ng/L HgCl₂对大鲵暴露48 h显著诱导了大鲵皮肤CATH-BF基因表达(P<0.05)，大鲵暴露于HgCl₂ 72 h后，HgCl₂对大鲵皮肤CATH-BF基因表达无显著影响；大鲵暴露于HgCl₂ 24 h后，不同质量浓度HgCl₂对大鲵心脏CATH-2基因表达水平有不同的影响，即1、10 ng/L对大鲵暴露24 h极显著下调了心脏CATH-2基因表达水平(P<0.01)，100 ng/L HgCl₂对大鲵暴露24 h极显著上调了心脏CATH-2基因表达水平(P<0.01)，10、100 ng/L HgCl₂对大鲵暴露48 h后显著下调了大鲵心脏CATH-2基因表达水平(P<0.05)；10、100 ng/L HgCl₂对大鲵暴露24 h显著下调了大鲵胰腺CATH-2基因表达水平(P<0.05)；1、10 ng/L HgCl₂对大鲵暴露24 h极显著诱导了心脏CATH-3基因表达水平(P<0.01)，大鲵暴露于HgCl₂ 24、48、72 h后，HgCl₂ 对胰腺CATH-3基因表达均无显著性影响。可见，HgCl₂ 对大鲵皮肤CATH-BF基因及胰腺和心脏CATH-2、CATH-3基因表达的影响处于动态变化模式，并且HgCl₂对大鲵胰腺和心脏CATH-2、CATH-3基因表达影响存在组织特异性差异。

In order to explore the effects of mercuric chloride(HgCl2) on the expression of CATH-BF in the skin and CATH-2 and CATH-3 in the heart and pancreas of Chinese giant salamander(Andrias davidianus),the juvenile stage giant salamanders were continuously exposed to 0(control),1,10,and 100 ng/L HgCl₂ for 24,48,72 h respectively,and the effects of mercuric chloride on the expression of CATH-BF in the skin and CATH-2 and CATH-3 in the heart and pancreas of Chinese giant salamander were investigated by real time quantitative RT-PCR method.After exposure to HgCl₂ for 24 h,the expression level of CATH-BF in the skin of giant salamander was reduced compared with the control group.1 and 100 ng/L HgCl₂ very significantly down-regulated the expression of CATH-BF in the skin (P<0.01). 10 ng/L HgCl₂ significantly down-regulated the expression of CATH-BF gene in the skin after exposure for 24 h(P<0.05).10 and 100 ng/L HgCl₂ significantly induced the expression of CATH-BF gene in the skin after exposure for 48 h(P<0.05).Exposure to HgCl₂ for 72 h had no significant effects on the expression of CATH-BF gene in the skin.Different concentrations of HgCl₂ had different effects on the expression of CATH-2 gene in the heart of the giant salamander.1 and 10 ng/L HgCl₂ significantly down-regulated the expression of CATH-2 gene in the heart after exposure for 24 h(P<0.01).100 ng/L HgCl₂ significantly up-regulated the expression of CATH-2 gene in the heart after exposure for 24 h(P<0.01).10 and 100 ng/L HgCl₂ significantly down-regulated the expression of CATH-2 gene in the heart of the giant salamander after 48 h of exposure(P<0.05).10 and 100 ng/L HgCl₂ significantly down-regulated the expression of CATH-2 gene in the pancreas after 24 h of exposure(P<0.05).1 and 10 ng/L HgCl₂ significantly induced the expression of CATH-3 gene in the heart after exposure to HgCl₂ for 24 h(P<0.01).HgCl2 had no significant effect on the expression of CATH-3 gene in the pancreas after 24, 48 and 72 h of exposure.It was concluded that the pattern of effects of mercuric chloride on the expression of CATH-BF in the skin and CATH-2 and CATH-3 in the heart and pancreas of Chinese giant salamander was dynamic,and the effects of HgCl₂ on the expression of CATH-BF in the skin and CATH-2 and CATH-3 in the heart and pancreas showed tissue specificity.