鳞翅目核仁小RNA Sf-15在逆境胁迫下的表达分析

Expression of Lepidopteran Small Nucleolar RNA Sf-15 Under Stress

核仁小RNA(small nucleolar RNA,snoRNA)除了能够指导rRNA修饰外,在肿瘤发生及生物响应逆境胁迫中也发挥着重要作用。课题组在前期研究中发现一个家蚕C/D box snoRNA Bm-15在鳞翅目昆虫中高度保守,在草地贪夜蛾细胞Sf9中干涉此snoRNA同源序列Sf-15后,细胞出现凋亡现象,与逆境相关的基因表达变化显著。为了进一步研究该snoRNA的功能,对Sf9细胞施加非生物胁迫紫外线照射(ultraviolet,UV)和生物胁迫病毒感染,检测snoRNA Sf-15在胁迫条件下表达量的变化。结果发现,UV处理后Sf9细胞中snoRNA Sf-15迅速响应,处理后4 h表达即上调,至8 h达高峰,随后其表达量逐渐下降;而且随着UV剂量的增大,snoRNA Sf-15的诱导表达量逐渐升高。Sf9细胞被AcMNPV病毒感染后,snoRNA Sf-15呈现先下降后上升再下降的趋势,感染后48 h表达量最高,病毒感染组48 h后Sf-15表达量整体高于对照组。结果表明snoRNA Sf-15在细胞响应非生物及生物胁迫过程中均发挥着重要的作用。该研究在鳞翅目昆虫中发现snoRNA可以参与细胞的逆境胁迫反应,为探索昆虫snoRNA的功能提供了新的思路。

Small nucleolar RNAs(snoRNAs)can not only guide the 2′-O ribosome methylation and pseudouridylation of rRNAs,but also play important roles in tumorigenesis and stress response in different organisms. In the previous study,it was found that a C/D box snoRNA Bm-15 of Bombyx mori was highly conserved in Lepidoptera. Knocking down snoRNA Sf-15 led to apoptosis and significant changes in expression of stress-related genes in Spodoptera frugiperda Sf9 cells.To further investigate the function of snoRNA Sf-15,ultraviolet(UV)and virus were applied to Sf9 cells,and changes in expression of snoRNA Sf-15 were investigated. Results showed that snoRNA Sf-15 in Sf9 cells responded rapidly to UV.Its expression level started to increase after 4 h treatment,reached to the top at 8 h post UV irradiation,and then decreased. With the accumulation of UV irradiation,expression level of snoRNA Sf-15 kept rising. When Sf9 cells were infected with Autographa californica multiple nucleopolyhedrovirus(AcMNPV),expression level of snoRNA Sf-15 decreased first,then increased to the highest level at 48 h post infection,which was higher than that of the control. These results indicated that snoRNA Sf-15 played an important role in response of Sf9 cell to abiotic and biotic stresses.It was found that snoRNA can participate in cell stress response in lepidopteran insects,which facilitates the study on function of snoRNAs in insect.