中国明对虾Rel／NF-κB家族基因在弧菌刺激下的表达

EXPRESSION OF Rel/NF-κB FAMILY FcRel GENE IN VIBRIO-CHALLENGED CHINESE SHRIMP FENNEROPENAEUS CHINENSIS

利用RT-PCR和RACE技术获得了中国明对虾Rel/NF-κB家族成员FcRel基因的部分cDNA片段,并研究了该基因在弧菌刺激条件下的转录表达变化。结果表明,该cDNA编码320个氨基酸,包含一个完整的RHD结构域和部分IPT-NFkappaB结构域。FcRel基因的RHD结构域与其它物种的RHD结构域的分子系统学分析表明,中国明对虾的FcRel与果蝇的Relish聚在一起,然后与疟蚊、烟草天蛾等其它节肢动物的Relish聚为一类。在弧菌刺激时,FcRel在血细胞和淋巴器官中的转录表达显示出不同的变化模式。在弧菌注射后3h和5h,血细胞中FcRel的转录表达出现明显下调;而弧菌注射引起淋巴器官中FcRel基因明显的上调表达。说明FcRel基因的表达与弧菌刺激密切相关,提示Relish可能参与了对虾抗菌反应的信号转导通路。

Rel/NF-κB is a group of nuclear transcription factors, and very important in mediating innate immune reactions in animals. RT-PCR and RACE techniques were applied in this study to produce partial cDNA fragments of FcRel-a member of Rel/NF-κB family from Chinese shrimp Fenneropenaeus chinensis. The cDNA fragment encoded 320 amino acids, including a whole RHD domain and a partial IPT-NFκB domain. Phylogenetic analysis on RHDs from different species shows that FcRel is categorized with the Relish of Drosophila melanogaster first, and then joined the Relish of Aedes aegypti and Bornbyx mori. Real-time PCR analysis revealed different expression profiles of FcRel gene between hemocytes and lymphoid organ of shrimp when they were challenged by Vibrio. The transcription of FcRel in hemocytes showed down-regulation 3h and 5h post-challenge, while that of FcRel in lymphoid organ showed apparent up-regulation post-challenge. It was indicated that the expression of FcRel was closely related to Vibrio challenge. Therefore, it is deduced that Relish may be involved in the signal transduction pathway of antibacterial response in shrimp.