College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China.
J Gen Virol. 2013 Jul;94(Pt 7):1669-1679. doi: 10.1099/vir.0.050583-0. Epub 2013 Mar 27.
Bombyx mori nucleopolyhedrovirus (BmNPV) BmP95 is a highly conserved gene that is found in all of the baculovirus genomes sequenced to date and is also found in nudiviruses. To investigate the role of BmP95 in virus infection in vitro, a BmP95 deletion virus (vBmP95-De) was generated by homologous recombination in Escherichia coli. Fluorescence and light microscopy and titration analysis indicated that the BmP95 deletion bacmid led to a defect in production of infectious budded virus (BV). However, deletion of BmP95 did not affect viral DNA replication. Electron microscopy showed that masses of aberrant tubular structures were present in cells transfected with the BmP95 deletion bacmid, indicating that deletion of BmP95 affected assembly of the nucleocapsid. This defect could be rescued by insertion of full-length BmP95 into the polyhedrin locus of the BmP95-knockout bacmid but not the N-terminal domain of BmP95. Together, these results showed that full-length BmP95 is essential for BV production and is required for nucleocapsid assembly.
家蚕核型多角体病毒（BmNPV）BmP95 是一个高度保守的基因，存在于迄今为止测序的所有杆状病毒基因组中，也存在于 nudiviruses 中。为了研究 BmP95 在病毒体外感染中的作用，通过大肠杆菌中的同源重组生成了 BmP95 缺失病毒（vBmP95-De）。荧光和光学显微镜以及滴定分析表明，BmP95 缺失 bacmid 导致传染性芽生病毒（BV）的产生缺陷。然而，BmP95 的缺失并不影响病毒 DNA 的复制。电子显微镜显示，用 BmP95 缺失 bacmid 转染的细胞中存在大量异常的管状结构，表明 BmP95 的缺失影响了核衣壳的组装。通过将全长 BmP95 插入 BmP95 敲除 bacmid 的多角体蛋白基因座，可以挽救这种缺陷，但插入 BmP95 的 N 端结构域则不行。总之，这些结果表明全长 BmP95 对于 BV 的产生是必不可少的，并且对于核衣壳的组装是必需的。
