摘要
杆状病毒在感染循环中产生的包涵体衍生病毒(occlusion-derived virus,ODV)介导病毒经口感染。由至少9种经口感染因子(per os infectivity factor,PIF)形成的复合体介导ODV感染昆虫中肠上皮细胞。为深入研究经口感染因子1(PIF1)的作用机制,克隆了家蚕核型多角体病毒(BmNPV)陕西分离株的pif1基因,序列分析显示其编码蛋白与苜蓿银纹夜蛾核型多角体病毒的PIF1氨基酸序列一致性为85%,含有2个RGD基序;5′RACE分析发现pif1转录起始位点位于起始密码子上游53 bp处,含有病毒晚期启动子的保守序列ATAAG;定量PCR分析显示pif1在感染晚期开始大量转录,一直持续到感染极晚期;利用瞬时表达系统将PIF1与EGFP融合表达,通过激光共聚焦显微镜观察荧光分布位置,结果发现荧光均匀分布于细胞质中,而在病毒感染后荧光进入细胞核中,表明PIF1在其他病毒因子参与下,被运输至细胞核中。研究结果为今后深入研究BmNPV PIF1在ODV经口感染中的作用奠定了基础。
Occlusion-derived virus(ODV) produced in baculovirus infection cycle mediates oral infection between insects. A big complex formed by at least 9 per os infectivity factors(PIFs) mediates ODV to infect insect midgut cell. To better understand the functional mechanism of PIF1, pif1 gene from Shaanxi strain of Bombyx mori nucleopolyhedrovirus(BmNPV) was amplified and sequenced. The deduced amino acid sequence shared 85% identity with that of Autographa californica multiple nuclearpolyhedrosisvirus(AcMNPV), and 2 RGD motifs were found according to sequence analysis. 5′ RACE result revealed that transcription start site of pif1 located in 53 bp upstream of ATG, where a typical late promoter motif ATAAG was found. Quantitative PCR analysis showed that pif1 gene was highly transcripted from the late stage to the very late stage of infection. PIF1 was expressed in transient expression system after it was fused to EGFP, and then its fluorescence distribution was observed under laser scanning confocal microscope. It was found that fluorescence of the fusion protein was distributed evenly in cytoplasm, whereas it entered into nucleus with the aid of virus infection, indicating that PIF1 was transported into nucleus with the help of other viral factors. In conclusion, this study laid a foundation for further research on the role of BmNPV PIF1 in oral infection of ODV.
作者
黄金山
程晨
Huang Jinshan;Cheng Chen(Jiangsu Key Laboratory of Sericultural Biology and Biotechnology,College of Biotechnology,Jiangsu University of Science and Technology,Zhenjiang Jiangsu 212018,China;Key Laboratory of Silkworm and Mulberry Genetic Improvement,Ministry of Agriculture and Rural Affairs,Sericultural Research Institute,Chinese Academy of Agricultural Sciences,Zhenjiang Jiangsu 212018,China)
出处
《蚕业科学》
CAS
CSCD
北大核心
2019年第4期525-530,共6页
ACTA SERICOLOGICA SINICA
基金
国家自然科学基金项目(No.31670152)
