斜纹夜蛾核多角体病毒感染甜菜夜蛾细胞的研究

Se301 Cells Infected by Spodoptera litura Nucleopolyhedrovirus

研究发现斜纹夜蛾核多角体病毒(Spodoptera litura nucleopolyhedrovirus,SpltNPV)不能成功感染同属甜菜夜蛾(S.exigua,Se)昆虫,为深入研究SpltNPV在离体Se301细胞中的感染进程以及病毒感染失败的原因,对感染后Se301细胞进行DNA复制、病毒基因转录以及病毒蛋白表达等检测。结果显示被感染的Se301细胞中病毒完成了DNA的复制和病毒早、晚期基因转录,但检测不到极晚期基因多角体基因(polyhedrin)的表达,病毒的蛋白表达受阻从而影响了病毒完成复制周期。研究发现病毒蛋白表达受阻是SpltNPV在Se301细胞中无法形成子代病毒,完成整个病毒复制的主要原因,这为深入研究其感染失败机理奠定了坚实基础。

Spodoptera litura（Splt）and Spodoptera exigua（Se） are both extremely serious agricultural lepidopteran pests and belong to the same family（Noctuidae） and the same genera（Spodoptera）.Splt nucleopolyhedrovirus（SpltNPV） and Se multiple nucleopolyhedrovirus（SeMNPV） are viral pathogens to the two insects,respectively.Comparative analysis of the complete genome sequences of SpltNPV and SeMNPV show two genomes are very similar.Although both the pathogens and the hosts are closely related,the mechanism of the two baculovirus not infecting the hosts each other is unclear.This study concentrate on investigating the reason of the Se301 cells by SpltNPV abortion infection.The replication of virus have completed in SpltNPV-infected Se301 cells by testing with dot blotting.The results of RT-PCR analysis displayed that all genes from very early genes to late genes have transcribed in the infected cells.Western blotting analysis revealed that it is no specific POLYHEDRIN with a size of 29 700 when using the POLYHEDRIN antiserum.Collectively,in the Se301 cells infected by SpltNPV,the replication of virus and the transcription of all late genes have happened,although it is not detected the expression of very late genes,suggesting that the blocking of SpltNPV proteins expression is the main limited factors in viral replication cycle.