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

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 Bombyx 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.