Zhang Chun-Nuan, Zhang Ji-Liang, Liu Wen-Bin, Wu Qiu-Jue, Gao Xiao-Chan, Ren Hong-Tao
College of Animal Science and Technology, Henan University of Scientific and Technology, Luoyang 471003, PR China.
College of Animal Science and Technology, Henan University of Scientific and Technology, Luoyang 471003, PR China.
Fish Shellfish Immunol. 2016 Jul;54:639-47. doi: 10.1016/j.fsi.2016.03.005. Epub 2016 Mar 8.
In the present study, the interleukin-6 gene (IL-6) cDNA in blunt snout bream (Megalobrama amblycephala) was identified and its expression profiles under ammonia stress and bacterial challenge were investigated. The IL-6 sequence consisted of 1045 bp, including a 696 bp ORF which translated into a 232 amino acid (AA) protein. The protein contained a putative signal peptide of 24 AA in length. IL-6 expression analysis showed that the it is differentially expressed in various tissues under normal conditions and the highest IL-6 level was observed in the intestine tissue, followed by the liver, and then in the gills. Under ammonia stress, the IL-6 mRNA level both in spleens and intestine increased significantly (P < 0.05), with the maximum levels attained at 6 h, 12 h (72, 10-fold, respectively). Thereafter, they all significantly decreased (P < 0.01) and returned to the basal value within 48 h. Whereas, in livers it slightly decreased at 3 h firstly (0.5-fold), and then significantly (P < 0.05) increased with the maximum level attained 12 h (3-fold). Further expression analysis showed that the mRNA level of IL-6 in spleens, intestine and livers of blunt snout bream all increased significantly (P < 0.05), with maximum values attained at 6 h, 3 h, 6 h (10, 6, 18-fold, respectively) after Aeromonas hydrophila (A. hydrophila) injection, and then decreased to the basal value within 24 h which suggested that IL-6 was involved in the immune response to A. hydrophila. The cloning and expression analysis of the IL-6 provide theoretical basis to further study the mechanism of anti-adverseness and expression characteristics under stress conditions in blunt snout bream.
在本研究中，鉴定了团头鲂（Megalobrama amblycephala）白细胞介素6基因（IL-6）的cDNA，并研究了其在氨应激和细菌攻击下的表达谱。IL-6序列由1045个碱基对组成，包括一个696个碱基对的开放阅读框，其编码一个232个氨基酸的蛋白质。该蛋白质包含一个长度为24个氨基酸的假定信号肽。IL-6表达分析表明，在正常条件下它在各种组织中差异表达，在肠道组织中观察到最高的IL-6水平，其次是肝脏，然后是鳃。在氨应激下，脾脏和肠道中的IL-6 mRNA水平均显著增加（P < 0.05），在6小时、12小时达到最高水平（分别为72倍、10倍）。此后，它们均显著下降（P < 0.01），并在48小时内恢复到基础值。而在肝脏中，它首先在3小时略有下降（0.5倍），然后显著增加（P < 0.05），在12小时达到最高水平（3倍）。进一步的表达分析表明，嗜水气单胞菌（A. hydrophila）注射后，团头鲂脾脏、肠道和肝脏中IL-6的mRNA水平均显著增加（P < 0.05），在6小时、3小时、6小时达到最大值（分别为10倍、6倍、18倍），然后在24小时内降至基础值，这表明IL-6参与了对嗜水气单胞菌的免疫反应。IL-6的克隆和表达分析为进一步研究团头鲂应激条件下的抗逆机制和表达特性提供了理论依据。
