Leitner Michael, Murigneux Valentine, Etebari Kayvan, Asgari Sassan
School of the Environment, The University of Queensland, Brisbane, Australia.
QCIF Facility for Advanced Bioinformatics, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
BMC Microbiol. 2025 Mar 25;25(1):164. doi: 10.1186/s12866-025-03898-5.
Wolbachia pipientis is an intracellular endosymbiotic bacterium that blocks the replication of several arboviruses in transinfected Aedes aegypti mosquitoes, yet its antiviral mechanism remains unknown. For the first time, we employed Nanopore direct RNA sequencing technology to investigate the impact of wAlbB strain of Wolbachia on the host's N-methyladenosine (mA) machinery and post-transcriptional modification landscape. Our study revealed that Wolbachia infection elevates the expression of genes involved in the mosquito's mA methyltransferase complex. However, knocking down these mA-related genes did not affect Wolbachia density. Nanopore sequencing identified 1,392 differentially modified mA DRACH motifs on mosquito transcripts, with 776 showing increased and 616 showing decreased mA levels due to Wolbachia. These mA sites were predominantly enriched in coding sequences and 3'-untranslated regions. Gene Ontology analysis revealed that genes with reduced mA levels were over-represented in functional GO terms associated with purine nucleotide binding functions critical in the post-transcriptional modification process of mA. Differential gene expression analysis of the Nanopore data uncovered that a total of 643 protein-coding genes were significantly differentially expressed, 427 were downregulated, and 216 were upregulated. Several classical and non-classical immune-related genes were amongst the downregulated DEGs. Notably, it revealed a critical host factor, transmembrane protein 41B (TMEM41B), which is required for flavivirus infection, was upregulated and methylated in the presence of Wolbachia. Indeed, there is a strong correlation between gene expression being upregulated in genes with both increased and decreased levels of mA modification, respectively. Our findings underscore Wolbachia's ability to modulate many intracellular aspects of its mosquito host by influencing post-transcriptional mA modifications and gene expression, and it unveils a potential link behind its antiviral properties.
嗜虫沙雷氏菌是一种细胞内共生细菌，它能阻止几种虫媒病毒在经转染的埃及伊蚊中复制，但其抗病毒机制尚不清楚。我们首次采用纳米孔直接RNA测序技术，研究了嗜虫沙雷氏菌的wAlbB菌株对宿主N-甲基腺苷（mA）机制和转录后修饰图谱的影响。我们的研究表明，感染嗜虫沙雷氏菌会提高参与蚊子mA甲基转移酶复合物的基因表达。然而，敲低这些与mA相关的基因并不会影响嗜虫沙雷氏菌的密度。纳米孔测序在蚊子转录本上鉴定出1392个差异修饰的mA DRACH基序，其中776个因嗜虫沙雷氏菌而使mA水平升高，616个则降低。这些mA位点主要富集在编码序列和3'非翻译区。基因本体分析显示，mA水平降低的基因在与嘌呤核苷酸结合功能相关的功能性GO术语中过度富集，而嘌呤核苷酸结合功能在mA的转录后修饰过程中至关重要。对纳米孔数据的差异基因表达分析发现，共有643个蛋白质编码基因显著差异表达，其中427个下调，216个上调。一些经典和非经典的免疫相关基因在下调的差异表达基因中。值得注意的是，研究发现一种黄病毒感染所需的关键宿主因子跨膜蛋白41B（TMEM41B）在嗜虫沙雷氏菌存在的情况下上调并发生甲基化。事实上，基因表达上调分别与mA修饰水平升高和降低的基因之间存在很强的相关性。我们的研究结果强调了嗜虫沙雷氏菌通过影响转录后mA修饰和基因表达来调节其蚊子宿主许多细胞内方面的能力，并揭示了其抗病毒特性背后的潜在联系。
