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Updated: May 20, 2025
Detecting Wolbachia Strain wAlbB in Aedes albopictus Cell Lines
Published on: June 1, 2022
Wolbachia elevates host methyltransferase expression and alters the m6A methylation landscape in Aedes aegypti
Michael Leitner1, Valentine Murigneux2, Kayvan Etebari3
1School of the Environment, The University of Queensland, Brisbane, Australia.
Abstract:
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 N6-methyladenosine (m6A) machinery and post-transcriptional modification landscape. Our study revealed that Wolbachia infection elevates the expression of genes involved in the mosquito's m6A methyltransferase complex. However, knocking down these m6A-related genes did not affect Wolbachia density. Nanopore sequencing identified 1,392 differentially modified m6A DRACH motifs on mosquito transcripts, with 776 showing increased and 616 showing decreased m6A levels due to Wolbachia. These m6A sites were predominantly enriched in coding sequences and 3'-untranslated regions. Gene Ontology analysis revealed that genes with reduced m6A levels were over-represented in functional GO terms associated with purine nucleotide binding functions critical in the post-transcriptional modification process of m6A. 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 m6A modification, respectively. Our findings underscore Wolbachia's ability to modulate many intracellular aspects of its mosquito host by influencing post-transcriptional m6A modifications and gene expression, and it unveils a potential link behind its antiviral properties.
Insights
Wolbachia bacteria alter mosquito gene expression and RNA modifications, specifically N6-methyladenosine (m6A) levels. This modulation of host post-transcriptional processes may explain Wolbachia's ability to block arbovirus replication.
Area of Science:
- Molecular Biology
- Genomics
- Vector Biology
Background:
- Wolbachia pipientis is an endosymbiotic bacterium used to control arboviruses in Aedes aegypti mosquitoes.
- The antiviral mechanisms of Wolbachia remain poorly understood.
- N6-methyladenosine (m6A) is a key RNA modification influencing gene expression.
Purpose of the Study:
- To investigate the impact of Wolbachia wAlbB strain on the host's m6A machinery and RNA modification landscape.
- To explore the relationship between Wolbachia infection, m6A modification, and gene expression in Aedes aegypti.
- To identify potential molecular mechanisms underlying Wolbachia-mediated antiviral activity.
Main Methods:
- Utilized Nanopore direct RNA sequencing to analyze m6A modifications and gene expression.
- Employed gene knockdown to assess the role of m6A-related genes.
- Performed Gene Ontology (GO) analysis and differential gene expression analysis.
Main Results:
- Wolbachia infection upregulated genes involved in the mosquito's m6A methyltransferase complex.
- Identified 1,392 differentially m6A-modified sites, with 776 increased and 616 decreased, predominantly in coding sequences and 3'-UTRs.
- Observed differential expression of 643 protein-coding genes, including downregulated immune genes and an upregulated host factor (TMEM41B) crucial for flavivirus infection.
Conclusions:
- Wolbachia significantly modulates host post-transcriptional m6A modifications and gene expression in Aedes aegypti.
- The study reveals a correlation between altered m6A levels and gene expression changes, including immune-related genes.
- These findings suggest that Wolbachia's influence on host RNA modifications is a key factor in its antiviral properties.
