仿刺参硫氧还蛋白基因在灿烂弧菌和鳗弧菌刺激下的应激表达特征

Expression of thioredoxin gene in sea cucumber(Apostichopus japonicus)stressed by Vibrio splendidus and V. anguillarum

分别用灿烂弧菌(Vibrio splendidus)和鳗弧菌(V.anguillarum)对仿刺参(Apostichopus japonicus)进行注射感染试验,取注射后0、3、6、9、12、24 h的仿刺参体壁、肠道、呼吸树、触手和体腔细胞5种组织或细胞进行了实时荧光定量PCR检测,分析硫氧还蛋白(Thioredoxin,Trx)基因在这5种组织或细胞中的表达特征,探讨了硫氧还蛋白在仿刺参先天免疫中的作用。结果显示,Trx基因在仿刺参体壁、肠道、触手、呼吸树及体腔细胞中均表达;在灿烂弧菌刺激下各组织或细胞中Trx基因变化趋势相似,呈现一种"突增-下降-再突增"的双峰型模式;鳗弧菌刺激下Trx基因表达量变化同样呈现先升高后降低的趋势,但与灿烂弧菌组相比反应时间与上调幅度都不同。总而言之,Trx基因在仿刺参体内有组成型和诱导型两种表达模式,并存在表达的组织特异性和病原特异性;Trx基因参与了仿刺参对病原感染的免疫应答,使机体免受氧化胁迫,在抵御外界病原入侵、维持胞内氧化还原状态方面起到重要作用。

Expressions of Thioredoxin （Trx） gene were analyzed by quantitative real-time PCR method in the body wall, intestine, respiratory tree, tentacles and coelomocyte of sea cucumber （Apostichopus japonicus） injected with Vibrio splendidus and V. anguillarum for 0 h, 3 h, 6 h, 9 h, 12 h, 24 h to explore the role of Thioredoxin protein in the innate immunity of sea cucumber. The Trx mRNA were identified by using quantitative real-time PCR in different tissues of sea cucumbers including the body wall, intestine, respiratory tree, tentacles and coelomocyte. Expression pat- terns of Trx in different tissues were similar in response to Vibrio splendidus, which presented a increase-discrease-in- crease model. Moreover, expressions of Trx after V. anguillarum challeng in directed tissues seemed different in reaction time and increased speed. These results suggested that expression of Trx presented constitutive and inducible patterns in all the detected tissues, and it was tissue-specific and pathogen-specific expression in the sea cucumber. Thus, Trx may play a very important role in resisting exogenous bacteria and balancing the cellular redox state.