西伯利亚鲟免疫球蛋白M重链区mRNA的组织分布和细菌感染后的表达

摘要

Tissue profiles and expression of immunoglobulin M heavy chain mRNA ( IgHM mRNA ) in normal and bacterial challenging Siberian sturgeon Acipenser baerii with body weight of (260. 2±37. 8) g were investigated by a primer designed based on Siberian sturgeon in GenBank,and by Sybrgreen real time PCR. The results showed that IgHM mRNA was expressed in abundance in spleen,a little amount of IgHM mRNA expression in liver and heart, and almost no IgHM mRNA expression in gill, hindgut, muscle, gonad and brain. The mortality was observed in the Siberian sturgeon with muscular injection of pathogenic bacterium Aeromonas veronii with density of 2. 0 ×107 CFU/mL at a dose of 0. 1 mL/100 g body weight at water temperature of 22. 6-24. 5℃ 40 h after injection. Sixty-two h after injection, however, no mortality was found in the Siberian sturgeon with IgHM mRNA expression in spleen at a level as that in the fish in the control group. The Siberian sturgeon challenged for 93 h showed as higher 3. 7 times IgHM mRNA expression in spleen as that in the fish in the control group, indicating that the challenged Siberian sturgeon had activated specific immune response.%根据GenBank登录的西伯利亚鲟Acipernser baerii免疫球蛋白M重链区mRNA ( IgHM mRNA)设计引物,进行SYBR green实时定量。结果表明：鲟的脑、鳃、性腺、心脏、后肠、肝脏、肌肉、脾脏8种组织中, IgHM mRNA在脾脏中表达最高,在肝脏和心脏中表达较少,在脑、鳃、性腺、后肠、肌肉5种组织中几乎不表达；在水温22.6~24.5℃时,按100 g体质量注射0.1 mL菌液,给体质量为(260.2±37.8) g的西伯利亚鲟注射浓度为2.0×107 CFU/mL的维氏气单胞菌Aeromonas veronii,注射后40 h鱼开始死亡,62 h后停止死亡,注射后直至62 h时,处理组脾脏IgHM mRNA表达量一直处于对照组水平,93 h时处理组脾脏IgHM mRNA显著升高(P<0.05),为93 h对照组含量的3.7倍,说明机体已经开始特异性免疫应答。