CLONING AND EXPRESSION OF CYP4C GENE IN PORTUNUS TRITUBERCULATUS
ZHANG Xiao-Yan;LI Jian;LIU Ping;CHEN Ping;SUN Ming;YANG Ai-Guo;Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences;Ocean University of Shanghai;Ocean University of China;Qingdao Huiquan Ocean Science and Technology Development Company Limited;
A complete cDNA sequence of CYP4C gene in Portunus trituberculatus was first cloned in RT-PCR and Smart-TM Race technology. The length of the CYP4C gene is 1888bp encoding a protein of 514 amino acids. Bioinformatics analysis deduced that the CYP4C gene protein molecular weight is 59.54kDa with a theoretical pI 8.08. The amino acid sequence has CYP conserved domains of helix K(ExxR) and heme-binding motif(FxxGxxxCxG). Blast analysis revealed that the similarities of CYP4C with C. maenas, L. vannamei, Macrobrachium nipponense, Fenneropenaeus chinensis, O. limosus, C. quadricarinatus were 88%, 72%, 66%, 59%, 60%, 59%, respectively. Real-time fluorescent quantitative PCR was used to assess the mRNA expression of CYP4C in different tissues and its expression level of CYP4C in salinity stress. The results show that CYP4C could be expressed in all tested tissues of P. trituberculatus, including hepatopancreas, muscle, eyes, gills, and heart, among them the highest expression level was observed in hepatopancreas, while the lowest in heart. The expression level of CYP4C was up-regulated distinctly in the hepatopancreas at salinity 45, and then gradually reduced with time to the level of control group after 48 h, while at salinity 11, the CYP4C expression dropped significantly below that of the control group 6 h later. The results imply that CYP4C is involved in the accommodation to salinity change and play an important role in its molting.