中文摘要：

采用RACE-PCR和RT-PCR方法获得大黄鱼组织蛋白酶L（Cathepsin三）基因的cDNA中间片段，片段长度为773bp。BLAST分析显示，大黄鱼CathepsinL基因cDNA片段与鲵鱼的同源性最高达到95％，与斑马鱼同源性为80％。实时定量分析了大黄鱼CathepsinL基因在宰杀当天和冷藏期间的mRNA水平，结果表明，大黄鱼0℃条件下冷藏0、5、10、15、20d肌肉中mRNA都具有相对稳定性，但是含量水平有差异并且是呈现下降趋势，宰杀当天的大黄鱼肌肉中CathepsinL基因mRNA含量水平最高，与冷藏5、10、15、20d的CathepsinL基因mRNA水平差异性极显著妒〈0．01），冷藏5d的Cathepsi，zL基因mRNA水平与15、20d的水平也达到了极显著水平（P〈0．01）。同时结果表明，在不同储藏时间CathepsinL基因的mRNA含量水平与肌肉TPA和pH等也表现了高度的相关性，表明Catheps咖三基因的mRNA含量可以作为评价大黄鱼冷藏期间肉品质指标的可行性和准确性。

英文摘要：

The cDNA fragments of Cathepsin L gene in Pseudosciaena crocea were amplified and quantified by RACE-PCR and RT-PCR. And the fragment length is 773bp. The analytical results of BLAST showed that the Cathepsin L gene in P crocea have 95% homology with the gene in brown croaker and 80% homology in zebra fish. And the mRNA level of Cathepsin L gene was determined by RT-PCR in different cold storage period. The results showed that mRNA in muscle was relatively stable at 0~C during 0, 5, 10, 15, 20d. However, the mRNA levels were different and declining in different storage period. The highest level of mRNA were determined in 0d and varied significantly between 0d and other storage period （P〈0.01）. Besides, the difference of mRNA levels between 5d, 15d and 20d were also obvious （P〈0.01）. And rnRNA level, TPA and pH values were highly correlated in different storage periods. Therefore, these results showed that mRNA level of Cathepsin L gene could be taken as an important evaluating indicator for P. crocea muscle in different cold storage period.