State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Virus Res. 2013 Nov 6;177(2):194-200. doi: 10.1016/j.virusres.2013.07.016. Epub 2013 Jul 30.
Rana grylio virus (RGV) is a pathogenic iridovirus that has resulted in high mortality in cultured frog. Here, a recombinant RGV (i53R-RGV-lacIO) containing the inducible lac repressor/operator system was constructed. i53R-RGV-lacIO was a conditional lethal mutant in which the expression of envelope protein 53R was regulated by IPTG. i53R-RGV-lacIO shared characteristics similar to RGV in the presence of IPTG. However, the expression level of 53R, the ability of plaques formation, and the virus titers were strongly reduced in the absence of IPTG. Electron microscopy showed that the number of progeny virus produced by i53R-RGV-lacIO was remarkably reduced without IPTG. Furthermore, over-expression of 53R in vitro could increase titers of i53R-RGV-lacIO in the absence of IPTG. Therefore, the current data suggested that the lac repressor/operator system could regulate gene expression in the recombinant iridovirus. Our study was thought to be the first report of the system in aquatic virus.
蛙病毒（Rana grylio virus，RGV）是一种致病的虹彩病毒，可导致养殖蛙类的高死亡率。在此，构建了一种含有诱导型 lac 阻遏蛋白/操纵子系统的重组 RGV（i53R-RGV-lacIO）。i53R-RGV-lacIO 是一种条件致死突变体，其包膜蛋白 53R 的表达受 IPTG 调控。在存在 IPTG 的情况下，i53R-RGV-lacIO 具有与 RGV 相似的特征。然而，在缺乏 IPTG 的情况下，53R 的表达水平、蚀斑形成能力和病毒滴度均显著降低。电子显微镜显示，i53R-RGV-lacIO 在缺乏 IPTG 的情况下产生的子代病毒数量明显减少。此外，53R 的体外过表达可提高缺乏 IPTG 时 i53R-RGV-lacIO 的病毒滴度。因此，目前的数据表明，lac 阻遏蛋白/操纵子系统可调节重组虹彩病毒中的基因表达。我们的研究被认为是该系统在水生病毒中的首次报道。
