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Abstract MultipleWolbachiastrains can block pathogen infection, replication and/or transmission inAedes aegyptimosquitoes under both laboratory and field conditions. However,Wolbachiaeffects on pathogens can be highly variable across systems and the factors governing this variability are not well understood. It is increasingly clear that the mosquito host is not a passive player in whichWolbachiagoverns pathogen transmission phenotypes; rather, the genetics of the host can significantly modulateWolbachia‐mediated pathogen blocking. Specifically, previous work linked variation inWolbachiapathogen blocking to polymorphisms in the mosquito alpha‐mannosidase‐2 (αMan2) gene. Here we use CRISPR‐Cas9 mutagenesis to functionally test this association. We developed αMan2 knockouts and examined effects on bothWolbachiaand virus levels, using dengue virus (DENV;Flaviviridae) and Mayaro virus (MAYV;Togaviridae).Wolbachiatitres were significantly elevated in αMan2 knockout (KO) mosquitoes, but there were complex interactions with virus infection and replication. InWolbachia‐uninfected mosquitoes, the αMan2 KO mutation was associated with decreased DENV titres, but in aWolbachia‐infected background, the αMan2 KO mutation significantly increased virus titres. In contrast, the αMan2 KO mutation significantly increased MAYV replication inWolbachia‐uninfected mosquitoes and did not affectWolbachia‐mediated virus blocking. These results demonstrate that αMan2 modulates arbovirus infection inA. aegyptimosquitoes in a pathogen‐ andWolbachia‐specific manner, and thatWolbachia‐mediated pathogen blocking is a complex phenotype dependent on the mosquito host genotype and the pathogen. These results have a significant impact for the design and use ofWolbachia‐based strategies to control vector‐borne pathogens.
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This content will become publicly available on December 1, 2026
Wolbachia enhances the survival of Drosophila infected with fungal pathogens
Background Wolbachia bacteria of arthropods are at the forefront of basic and translational research on multipartite host-symbiont-pathogen interactions. These vertically transmitted microbes are the most widespread endosymbionts on the planet due to factors including host reproductive manipulation and fitness benefits. Importantly, some strains of Wolbachia can inhibit viral pathogenesis within and between arthropod hosts. Mosquitoes carrying the wMel Wolbachia strain of Drosophila melanogaster have a greatly reduced capacity to spread viruses like dengue and Zika to humans. While significant research efforts have focused on viruses, relatively little attention has been given to Wolbachia-fungal interactions despite the ubiquity of fungal entomopathogens in nature. Results Here, we demonstrate that Wolbachia increase the longevity of their Drosophila melanogaster hosts when challenged with a spectrum of yeast and filamentous fungal pathogens. We find that this pattern can vary based on host genotype, sex, and fungal species. Further, Wolbachia correlates with higher fertility and reduced pathogen titers during initial fungal infection, indicating a significant fitness benefit. Finally, RNA sequencing results show altered expression of many immune and stress response genes in the context of Wolbachia and fungal infection, suggesting host immunity may be involved in the mechanism. Conclusions This study demonstrates Wolbachia’s protective role in diverse fungal pathogen interactions and determines that the phenotype is broad, but with several variables that influence both the presence and strength of the phenotype. It also is a critical step forward to understanding how symbionts can protect their hosts from a variety of pathogens.
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- Award ID(s):
- 2330095
- PAR ID:
- 10572824
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- BMC Biology
- Volume:
- 23
- Issue:
- 1
- ISSN:
- 1741-7007
- Page Range / eLocation ID:
- 42
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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