New Model for the Genesis and Maturation of Viroplasms Induced by Fijiviruses in Insect Vector Cells
New Model for the Genesis and Maturation of Viroplasms Induced by Fijiviruses in Insect Vector Cells
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昆虫载体细胞中斐济病毒诱导病毒质发生和成熟的新模型
DOI：
10.1128/jvi.00409-13
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发表时间：
2013-06-01
影响因子：
5.4
通讯作者：
Wei, Taiyun
中科院分区：
文献类型：
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作者：
Mao, Qianzhuo;Zheng, Shenglan;Wei, Taiyun
植物呼肠孤病毒被认为在称为病毒质的细胞质、非膜性结构中复制和组装。在这里，我们建立了白背飞虱的连续细胞培养，以研究南方水稻黑条矮缩病毒(SRBSDV)在其昆虫媒介感染过程中诱导病毒质发生和成熟的机制。电子显微镜和共聚焦显微镜显示，病毒质由聚集病毒RNA和非结构蛋白P6和P9-1的颗粒区和聚集病毒RNA、子代核心、病毒颗粒以及非结构蛋白P5和P6的丝状区组成。我们的结果表明，丝状病毒质基质是子代病毒粒子的组装部位。由于病毒RNA是由丝状病毒质基质中组装的核心颗粒产生的，我们认为这些病毒RNA可能被运输到颗粒状病毒质基质中。在无病毒感染的情况下，P5形成丝状包涵体，P9-1形成颗粒状包涵体，提示P5和P9-1分别主要形成丝状和颗粒状病毒质基质。通过与P9-1和P5的直接相互作用，P6明显被募集到整个病毒质基质中。因此，本研究结果提示，P5、P6和P9-1共同是SRBSDV感染诱导的丝状和颗粒状病毒基质发生和成熟所必需的。在这些结果的基础上，我们提出了一个新的模型来解释昆虫载体细胞中由FijiVirus诱导的病毒质的发生和成熟。
Plant reoviruses are thought to replicate and assemble within cytoplasmic, nonmembranous structures called viroplasms. Here, we established continuous cell cultures of the white-backed planthopper (Sogatella furcifera Horváth) to investigate the mechanisms for the genesis and maturation of the viroplasm induced by Southern rice black-streaked dwarf virus (SRBSDV), a fijivirus in the family Reoviridae, during infection of its insect vector. Electron and confocal microscopy revealed that the viroplasm consisted of a granular region, where viral RNAs and nonstructural proteins P6 and P9-1 accumulated, and a filamentous region, where viral RNAs, progeny cores, viral particles, as well as nonstructural proteins P5 and P6 accumulated. Our results suggested that the filamentous viroplasm matrix was the site for the assembly of progeny virions. Because viral RNAs were produced by assembled core particles within the filamentous viroplasm matrix, we propose that these viral RNAs might be transported to the granular viroplasm matrix. P5 formed filamentous inclusions and P9-1 formed granular inclusions in the absence of viral infection, suggesting that the filamentous and granular viroplasm matrices were formed primarily by P5 and P9-1, respectively. P6 was apparently recruited in the whole viroplasm matrix by direct interaction with P9-1 and P5. Thus, the present results suggested that P5, P6, and P9-1 are collectively required for the genesis and maturation of the filamentous and granular viroplasm matrix induced by SRBSDV infection. Based on these results, we propose a new model to explain the genesis and maturation of the viroplasms induced by fijiviruses in insect vector cells.