Zhang Xing, Zhang Yunshan, Dai Kun, Liang Zi, Zhu Min, Pan Jun, Zhang Mingtian, Yan Bingyu, Zhu Hanxue, Zhang Ziyao, Dai Yaping, Cao Manman, Gu Yuchao, Xue Renyu, Cao Guangli, Hu Xiaolong, Gong Chengliang
School of Biology and Basic Medical Science, Soochow University, Suzhou, China.
Institute of Agricultural Biotechnology and Ecological Research, Soochow University, Suzhou, China.
Front Microbiol. 2020 Jan 10;10:2988. doi: 10.3389/fmicb.2019.02988. eCollection 2019.
nucleopolyhedrovirus (BmNPV) is one of the most serious pathogens in sericulture and causes huge economic loss annually. The roles of N6-methyladenosine (m6A) modification in silkworms following BmNPV infection are currently unclear. Here, methylated RNA immunoprecipitation with next-generation sequencing were applied to investigate the m6A profiles in silkworm midgut following BmNPV infection. A total of 9144 and 7384 m6A peaks were identified from the BmNPV-infected (TEST) and uninfected silkworm midguts (CON), respectively, which were distributed predominantly near stop codons. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of common m6A peaks in nuclear genes revealed that these m6A-related transcripts were associated with crucial signaling pathways. Comparative transcriptome analysis showed that 1221 differential expressed m6A peaks were identified between TEST and CON, indicating that m6A modification is regulated following BmNPV infection. GO and KEGG pathway analysis of the differentially expressed m6A peaks showed their association with signal transduction, translation, and degradation. To understand further the effect of the m6A machinery on virus infection, expression levels of m6A-related genes were altered in silencing and overexpression experiments. Expression of viral structural protein VP39 was increased in BmN cells by siRNA-mediated depletion of methyltransferase-like (METTL) enzyme genes (BmMETTL3, BmMETTL14) and cytoplasmic YTH-domain family 3 (BmYTHDF3), while the reverse results were found after overexpression of the m6A-related enzymes in BmN cells. Overall, m6A modification might be a novel epigenetic mechanism that regulation BmNPV infection and interference with this mechanism may provide a novel antiviral strategy for preventing BmNPV disease.
核型多角体病毒（BmNPV）是养蚕业中最严重的病原体之一，每年造成巨大的经济损失。目前尚不清楚N6-甲基腺苷（m6A）修饰在BmNPV感染后的家蚕中的作用。在此，采用甲基化RNA免疫沉淀结合下一代测序技术，研究BmNPV感染后家蚕中肠的m6A图谱。分别从感染BmNPV的（TEST）和未感染的家蚕中肠（CON）中鉴定出9144个和7384个m6A峰，这些峰主要分布在终止密码子附近。对核基因中常见m6A峰的基因本体论（GO）和京都基因与基因组百科全书（KEGG）分析表明，这些与m6A相关的转录本与关键信号通路有关。比较转录组分析显示，在TEST和CON之间鉴定出1221个差异表达的m6A峰，表明m6A修饰在BmNPV感染后受到调控。对差异表达的m6A峰进行GO和KEGG通路分析，表明它们与信号转导、翻译和降解有关。为了进一步了解m6A机制对病毒感染的影响，在沉默和过表达实验中改变了m6A相关基因的表达水平。通过siRNA介导的甲基转移酶样（METTL）酶基因（BmMETTL3、BmMETTL14）和细胞质YTH结构域家族3（BmYTHDF3）的缺失，BmN细胞中病毒结构蛋白VP39的表达增加，而在BmN细胞中过表达m6A相关酶后则得到相反的结果。总体而言，m6A修饰可能是一种新的表观遗传机制，调节BmNPV感染，干扰这一机制可能为预防BmNPV疾病提供一种新的抗病毒策略。
