Novel macula-like virus identified in Bombyx mori cultured cells
Novel macula-like virus identified in Bombyx mori cultured cells
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DOI：
10.1128/jvi.79.9.5577-5584.2005
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发表时间：
2005-05-01
影响因子：
5.4
通讯作者：
Shimada, T
中科院分区：
文献类型：
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作者：
Katsuma, S;Tanaka, S;Shimada, T
我们发现了一个全长6,513个碱基的新RNA，命名为家蚕斑点样潜伏病毒(BmMLV)RNA，该RNA在家蚕BmN细胞中大量表达。BmMLV RNA可能编码两种蛋白质，推测的RNA复制酶和外壳蛋白，这两种蛋白质与植物RNA病毒MaculaVirus的结构特征和序列相似。Northern印迹分析表明，在BMN细胞中表达了两个转录本：6.5kb长的RNA，包含可能的RNA复制酶和外壳蛋白基因；以及1.2kb长的RNA，只包含外壳蛋白基因。Southern杂交分析表明，家蚕基因组不携带BmMLV RNA。RT-PCR分析还发现，除BmN细胞外，其他几个家蚕细胞系中也存在BmMLV RNA，这表明BmMLV RNA潜伏在家蚕培养细胞中。感染研究表明，BmMLV病毒粒子能够感染BmMLV阴性的果蝇SF-9细胞和家蚕幼虫。电子显微镜和Northern杂交分析表明，纯化的BmMLV病毒粒子直径为28~30 nm，含有6.5kb的基因组RNA。这些结果表明，BmMLV是一种新的感染家蚕细胞并可在其上复制的斑疹样病毒。
We identified a novel, 6,513-bp-long RNA, termed Bombyx mori macula-like latent virus (BmMLV) RNA, which abundantly expressed in B. mori cultured BmN cells. BmMLV RNA potentially encodes two proteins, putative RNA replicase and coat protein, which share structural features and sequence similarities with those of a plant RNA virus, the genus Maculavirus. Northern blot analysis showed that two transcripts were expressed in BmN cells: a 6.5-kb-long RNA, which contains both putative RNA replicase and coat protein genes, and a 1.2-kb-long RNA, which contains only a coat protein gene. Southern blot analysis showed that BmMLV RNA is not carried by the B. mori genome. RT-PCR analysis also revealed the presence of BmMLV RNA in several B. mori cell lines other than BmN cells, suggesting that BmMLV RNA latently exists in B. mori cultured cells. Infection studies showed that BmMLV virions were able to infect BmMLV-negative Spodoptera frugiperda Sf-9 cells and B. mori larvae. Electron microscopy and Northern blot analysis of a purified BmMLV revealed that isometric virions appear to be 28 to 30 nm in diameter and contain a 6.5-kb genomic RNA. These results showed that BmMLV is a novel macula-like virus infectious to and replicable in B. mori-derived cells.