【作者】 雷开宇；

【导师】 徐洵；

【作者基本信息】 厦门大学 ， 生物化学与分子生物学， 2007， 硕士

【摘要】 血蓝蛋白主要存在于甲壳纲,多足纲,肢口纲和蛛形纲动物体内。作为血淋巴的主要组成成分,血蓝蛋白大概占血淋巴总蛋白含量的95%以上。血蓝蛋白在对虾肝胰腺内被合成,并以六聚体为一单位的形式游离在血淋巴中,负责氧气的运输起着"分子肺"(即呼吸蛋白)的作用。另外,血蓝蛋白作为一种多功能蛋白还被证实参与一些生理过程,如渗透压的调节、能量的贮藏和酶的活力。而最受我们关注的是血蓝蛋白已被发现在节肢动物和软体动物的天然免疫系统起着重要的作用,但主要集中在抗菌防御体系,而但对血蓝蛋白在抗病毒防御体系中的作用人们却知之甚少。我们的研究中发现纯化的天然状态的血蓝蛋白在体内能够显著地减缓白斑杆状病毒对对虾的感染。因此,我们从日本囊对虾中克隆得到了两个血蓝蛋白亚基的基因(PjHcL和PjHcY)。有趣的是我们发现病毒感染对这两个亚基的表达产生了不同的影响。病毒的侵染诱导了大量PjHcL基因mRNA的转录,但PjHcY基因却无明显变化。而且,在抗病对虾体内我们也发现血蓝蛋白的表达量显著升高,同时在转录水平,相比于PjHcY基因,PjHcL基因明显上调。这些发现不但揭示了对虾血蓝蛋白在抗病毒防御系统中的重要作用,还提示我们血蓝蛋白这两个不同亚基可能在对虾天然免疫系统中发挥着不同的作用。更多还原

【Abstract】 Hemocyanin occurs in several classes: Crustacea, Myriapoda, Merostomata and Arachnida. As the main protein component of hemolymph, hemocyanin typically represents up to 95% of the total amount of protein. Hepatopancreas has been shown to be the site of hemocyanin synthesis. Hemocyanin (hexamer form) is freely dissolved in shrimp hemolymph and mainly responsible for oxygen transport.In addition to their primary function as an oxygen carrier for many arthropods, it has been suggested that hemocyanins would be multifunctional proteins involved in physiological processes such as osmoregulation, protein storage or enzymatic activities. Although it was also found to function in innate immunity of many arthropods and mollusks, involvement of hemocyanin in antiviral defense is seldom reported. In this study, we found that purified shrimp hemocyanin significantly delayed the infection of shrimp white spot syndrome virus (WSSV) in vivo.Two hemocyanin subunit genes (PjHcY and PjHcL) were thus cloned from Marsupenaeus japonicus. Interestingly, the effect of viral infection on the expression of these two subunits was different. PjHcL mRNA was strongly induced by WSSV infection while PjHcY varied little. Moreover, in WSSV-resistant shrimp, a much more significant up-regulation was found on the expression of PjHcL comparing with PjHcY. These findings not only reveal an important role of shrimp hemocyanin in antiviral defense, but also suggest a possible difference between its subunits in shrimp innate immunity.更多还原