东方蜜蜂微孢子虫侵染中华蜜蜂过程中的高表达基因表达谱及其潜在作用

Expression profile of high-expressing genes and its potential role during Apis cerana cerana infected by Nosema ceranae

摘要:

本研究旨在通过高通量测序技术和生物信息学方法探究东方蜜蜂微孢子虫（Nosema ceranae）在侵染中华蜜蜂（Apis cerana cerana，简称中蜂）过程中的高表达基因（highly expressed gene, HEG）表达谱及潜在作用.利用RNA-seq技术对N. ceranae感染后7d和10d的中蜂工蜂中肠进行测序，通过连续比对东方蜜蜂（Apis cerana）和N. ceranae的基因组，滤除中蜂的数据，得到侵染中蜂工蜂的N. ceranae（Nc1和Nc2）的有效读段数分别为180 237 114和36 054 033条.根据FPKM值大于15的标准，从Nc1和Nc2中分别筛选出1 482和901个HEG.Venn分析结果显示二者的共有HEG数为890个，特有HEG数分别为592和11个.GO分类和KEGG通路富集分析结果显示，上述共有HEG分布于24个功能条目和富集于72条代谢通路.进一步分析发现分别有2个HEG富集在与真菌的应激反应和毒力密切相关的MAPK信号通路.此外，N. ceranae的孢壁蛋白等毒力因子编码基因和ATP/ADP转移酶基因等能量代谢相关蛋白编码基因在侵染过程维持高量表达.通过RT-PCR验证了随机挑选的8个HEG的表达.研究结果提供了N. ceranae在侵染中蜂工蜂过程中的HEG表达谱及潜在作用.

Abstract:

To investigate the expression profile of highly expressed genes (HEGs) and its potential role during Apis cerana cerana infected by Nosema ceranae, RNA-seq was used to sequence the midguts of A. c. cerana workers at 7 d and 10 d postinfection by N. ceranae, followed by continuously mapping the genomes of Apis cerana and N. ceranae to filter out the data of A.c.cerana. In total, 180 237 114 and 36 054 033 clean reads were obtained from N. ceranae infecting A. c. cerana worker (Nc1 and Nc2), respectively. According to the criterion that the FPKM value >15, 1 482 and 901 HEGs in Nc1 and Nc2 were filtered out, respectively. Venn analysis showed that the total number of HEGs of the two groups was 890, and the number of specific HEGs was 592 and 11, respectively. Besides, GO classification and KEGG pathway enrichment analysis indicated the shared HEGs were distributed in 24 GO terms and enriched in 72 pathways. Further analysis demonstrated two HEGs were enriched in MAPK signaling pathway, which is closely associated with the stress response and virulence. Besides, some genes coding virulence factors such as spore wall protein, and several genes coding energy metabolismassociated proteins, such as ATP/ADP translocase were highly expressed during N. ceranae infection of A. c. cerana worker. Finally, eight randomly selected HEGs were confirmed using RT-PCR. Together, these results reveal the expression profile and potential role of HEGs during N. ceranae infection of A. c. cerana worker.