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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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Aedes aegypti gut transcriptomes respond differently to microbiome transplants from field‐caught or laboratory‐reared mosquitoes
Abstract The mosquito microbiome is critical for host development and plays a major role in many aspects of mosquito biology. While the microbiome is commonly dominated by a small number of genera, there is considerable variation in composition among mosquito species, life stages, and geography. How the host controls and is affected by this variation is unclear. Using microbiome transplant experiments, we asked whether there were differences in transcriptional responses when mosquitoes of different species were used as microbiome donors. We used microbiomes from four different donor species spanning the phylogenetic breadth of the Culicidae, collected either from the laboratory or the field. We found that when recipients received a microbiome from a donor reared in the laboratory, the response was remarkably similar regardless of donor species. However, when the donor had been collected from the field, many more genes were differentially expressed. We also found that while the transplant procedure did have some effect on the host transcriptome, this is likely to have had a limited effect on mosquito fitness. Overall, our results highlight the possibility that variation in mosquito microbiome communities is associated with variability in host–microbiome interactions and further demonstrate the utility of the microbiome transplantation technique for investigating host–microbe interactions in mosquitoes.
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- Award ID(s):
- 2019368
- PAR ID:
- 10485064
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Environmental Microbiology
- Volume:
- 26
- Issue:
- 2
- ISSN:
- 1462-2912
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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