Abstract：
Mandarinfish ranavirus (MRV), also known as a variant of largemouth bass virus (LMBV), is an emerging pathogen in mandarinfish aquaculture. In this study, monoclonal antibodies (mAbs) against MRV were produced and characterized, and 7 mAbs were obtained through Western blotting screening and all 7 mAbs specifically recognized MRV/LMBV but not several piscine iridoviruses as ISKNV, GIV and TFV. By LC MS/MS analysis, the recognized viral proteins by seven mAbs were identified as MRV-pORF47L, MRV-pORF55R, MRV-pORF57L, MRV-pORF77L and MRV-pORF78L, respectively, and all five viral proteins are late expression structural proteins by Western blotting. Based on mAb 1C4, immuno-histochemistry and immuno-histo-fluorescence were performed to re-assess the tissue tropism of MRV. The result showed that abundant reactive signals were observed in infected spleen, kidney as well as intestine and pyloric caecum. Real-time quantitative PCR also demonstrated that spleen as well as pyloric caecum and intestines are the major target tissue upon MRV infection. In infected intestines and pyloric caecum, numerous enlarged, multinucleated cells with intracytoplasmic inclusions were identified as the target cells of MRV, suggesting that MRV serves as a digestive tract pathogen to mandarinfish, which may explain why acute infection of MRV can cause the typical clinicopathology featured by severe ascites.
摘要：
曼陀林鱼病毒（MRV），也被称为大嘴鲈鱼病毒（LMBV）的变种，是普通话水产养殖中新兴的病原体。在这项研究中,产生并鉴定了抗MRV的单克隆抗体（mAb），通过蛋白质印迹筛选获得7个mAb，所有7个mAb均特异性识别MRV/LMBV，但未将几种猪虹膜病毒识别为ISKNV，GIV和TFV。通过LCMS/MS分析，由七个单克隆抗体识别的病毒蛋白被鉴定为MRV-PORF47L，MRV-pORF55R,MRV-pORF57L,MRV-pORF77L和MRV-pORF78L,分别,通过蛋白质印迹法，所有五种病毒蛋白都是晚期表达结构蛋白。基于mAb1C4,进行免疫组织化学和免疫组织荧光以重新评估MRV的组织嗜性。结果表明，在感染的脾脏中观察到丰富的反应信号，肾脏以及肠和幽门盲肠。实时定量PCR还表明，脾脏以及幽门盲肠和肠是MRV感染的主要靶组织。在感染的肠道和幽门盲肠中，大量放大，具有胞浆内包涵体的多核细胞被鉴定为MRV的靶细胞，这表明MRV是橘鱼的消化道病原体，这可以解释为什么MRV的急性感染可以导致典型的临床病理特征为严重的腹水。
