Cloning And Expression Of Nuclear Transcription Factors Rel/NF-κB Family Genes In Chinese Shrimp Fenneropenaeus Chinensis

Shrimp cultivation has been suffering serious problems due to the outbreak of diseases throughout the world. The key point to solve this problem is to explore the immune mechanism of shrimp and to find effective methods to control the diseases. Rel/NF-κB family is reported as a transcription factor, which plays a central role in the innate immunity in invertebrates.In this study, degenerate primers were designed according to the sequence homologous with the same genes from other species. Then SMART RACE was used to obtain the full lengths of Relish (FcRelish) and Dorsal (FcDorsal) in Chinese shrimp Fenneropenaeus chinensis. The full length of FcRelish gene is 2157 bp and that of FcDorsal is 1627 bp respectively. The expression of above two genes was analyzed in 12 tissues of shrimp including haemocytes, lymphoid organ, intestine, muscle etc. FcRelish and FcDorsal transcripts in hemocytes and lymphoid organ are higher than those in the other tissues. Since the haemocytes and lymphoid organ play very important roles in the immune reaction of shrimp, FcRelish and FcDorsal might act as important immune factors in shrimp.Real time PCR technique was applied to quantify the transcripts of FcRelish and FcDorsal gene in haemocytes and lymphoid organ when shrimp were challenged by inactivated Vibrio and WSSV. After challenged with WSSV, the expression profile of FcRelish showed a wavy changing curve in both haemocytes and lymphoid organ, which indicate that FcRelish may play an important function when shrimp were challenged by WSSV. The expression of FcRelish in haemocytes does not change obviously after being stimulated by Vibrio, but it showed great variation in lymphoid organ instead. While the expressions of FcDorsal in hemocytes and lymphoid organ are up-regulated significantly when shrimp were stimulated by inactivated Vibrio, which might illuminate that the expression of FcDorsal is sensitive to Vibrio.As a transcription factor, only hydrolyzed NF-κB can activate the transcription of downstream genes. To study the mechanism of shrimps against bacteria and virus challenge, the variation of these two genes at translation level will be studied further.