pH、氨氮胁迫对中国对虾HSP90基因表达的影响

Effects of pH and Ammonia-N Stress on HSP90 Gene Expression of Fenneropenaeus chinensis

中文关键词: 中国对虾  HSP90基因  pH胁迫  氨氮胁迫

英文关键词: Fenneropenaeus chinensis  Heat shock protein 90 (HSP90)  pH stress  Ammonia-N stress

中文摘要:

      研究了pH、氨氮胁迫对中国对虾Fenneropenaeus chinensis血细胞、肝胰腺、鳃和肌肉组织HSP90基因时空表达的影响。分别将中国对虾暴露于pH 7.0、9.0的水体中148h和不同氨氮浓度的水体中96h，结果表明，pH（7.0，9.0）胁迫条件下中国对虾鳃、肌肉和血细胞HSP90基因表达均上调，肝胰腺HSP90基因表达对两种pH胁迫差异明显：pH 7.0胁迫条件下，HSP90基因表达3h达峰值后明显降低；pH 9.0胁迫时，HSP90基因表达水平逐渐升高，整个胁迫过程中均显著高于对照组（P＜0.05），说明中国对虾肝胰腺组织是高pH胁迫的响应器官。6mg/L氨氮浓度组鳃和肌肉组织HSP90基因表达水平24h达最高值，分别为对照组的5.46和1.55倍；各胁迫组肝胰腺和血细胞HSP90基因表达水平分别于6h和48h达到最高值，为对照组的1.33~2.08倍和2.20~5.45倍。肝胰腺组织对氨氮胁迫表现敏感，短时间内（6h）通过上调HSP90基因表达水平保护细胞；鳃组织HSP90基因表达波动范围最大，说明鳃组织需要更高表达量的HSP90保护细胞。当氨氮浓度持续48~96h维持在2~6mg/L，各组织HSP90基因表达水平显著降低。

英文摘要:

      Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone contributing to the folding, maintenance of structural integrity and proper regulation of a subset of cytosolic proteins. HSP90 is identified in some crustaceans, however, few studies on the transcript of HSP90 gene in Chinese shrimp Fenneropenaeus chinensis in response to environmental pH and ammonia-N stresses have been reported. In the pH stress experiment, F. chinesis were exposed to marine water with the pH value of 7.0, 9.0 for 148h. During the ammonia-N stress experiment, F. chinensis were exposed to marine water with different concentration of ammonin-N for 96h. The gene expression profiling of HSP90 in different tissues (gill, hepatopancreas, muscle and haemocytes) after pH and ammonia-N stresses were analyzed by quantitative RT-PCR. The HSP90 gene expression in gill, muscle and haemocytes of Chinese shrimp increased when exposed to pH 7.0 and pH 9.0, but the time of the highest gene expression level is different. Obvious different expression of HSP90 gene in hepatopancreas exposed to pH 7.0 and pH 9.0 stress was observed. HSP90 transcripts increased to its highest level post-stress at 3h and then decreased in the pH 7.0 treatment, while in the pH 9.0 treatment the HSP90 gene expression was always higher than that in the control, which indicated the hepatopancreas of Chinese shrimp was the responsive organ to the high pH stress. When the concentration of ammonia-N in marine water was 6 mg/L, the gene HSP90 expression in gill and muscle reached its highest level about 5.46-fold and 1.55-fold respectively post-stress at 24h. HSP90 expression in hepatopancreas and heamocytes in all treatments increased to the maximum value in the range of 1.33~2.08 times and 2.20~5.45 times post-stress at 6h and 48h respectively. The results indicated that the hepatopancreas of Chinese shrimp is more sensitive to ammonia-N stress than other tissues, in which HSP90 expression was up regulated drastically at 6h. It is also illustrated that gill needs higher expression of HSP90 gene than other tissues for cell protection based on the results of the large fluctuation range of HSP90 gene expression in gill. When the concentration of ammonia-N was continuously higher than 2~6 mg/L, the HSP90 expression in all tested tissues was significantly decreased.