注射黄芪多糖对吉富罗非鱼热应激蛋白基因表达的影响

摘要

将黄芪多糖(APS)用无菌生理盐水配制成2 mg/mL(低剂量)、20 mg/ mL(高剂量)两种针剂,腹腔注射吉富罗非鱼(Oreochromis niloticus).分别在注射后0h、24h、48 h、72 h和96 h采样提取吉富罗非鱼鳃、头肾、肝脏和脾脏组织中的总RNA,并反转录成cDNA,利用Real-time PCR方法对不同组织中的热应激蛋白(hsp70)基因表达进行定量分析.结果显示,在24h时,高剂量组吉富罗非鱼鳃、头肾和肝脏三个组织中hsp70基因的表达量显著高于同期对照组(P＜0.05),之后表达量快速降低,低剂量组hsp70基因表达量仅在脾脏中有上调.实验表明,APS可通过诱导吉富罗非鱼hsp70基因表达来保护免疫细胞免受应激损伤,从而增强鱼体抵抗病原菌的能力.%Astragalus polysaccharides (APS) was dissolved in sterile saline at the doses of 2 mg/mL (low dose), 20 mg/mL (high dose) to inject Oreochromis niloticus intraperitoneally, and the effects of APS on gene expression of hsp70 in gill, head kidney, liver and spleen of 0. Niloticus were determined using quantitative real-time polymerase chain reac tion at 24 h, 48 h, 72 h and 96 h after intraperitoneal injection. The results revealed that the gene expression level of hsp70 in gill, head kidney and liver of high dose group increased significantly than those of control group (P <0. 05) at 24 h, but decreased quickly afterwards. The gene expression of hsplO was up-regulated only in the spleen in low dose group (P <0.05) at 24 h. These results indicated that APS could protect immune cell from heat injury and enhance the fish immunity against infection of bacterial pathogen by inducing the expression of hsp70 of 0. Niloticus.