Larval habitat determines the bacterial and fungal microbiota of the mosquito vector Aedes aegypti

Abstract

Mosquito larvae are naturally exposed to microbial communities present in a variety of larval development sites. Several earlier studies have highlighted that the larval habitat influences the composition of the larval bacterial microbiota. However, little information is available on their fungal microbiota, i.e. the mycobiota. In this study, we provide the first simultaneous characterization of the bacterial and fungal microbiota in field-collected Aedes aegypti larvae and their respective aquatic habitats. We evaluated whether the microbial communities associated with the breeding site may affect the composition of both the bacterial and fungal communities in Ae. aegypti larvae. Our results show a higher similarity in microbial community structure for both bacteria and fungi between larvae and the water in which larvae develop than between larvae from different breeding sites. This supports the hypothesis that larval habitat is a major factor driving microbial composition in mosquito larvae. Since the microbiota plays an important role in mosquito biology, unravelling the network of interactions that operate between bacteria and fungi is essential to better understand the functioning of the mosquito holobiont.

Patterns of Fungal Community Assembly Across Two Culex Mosquito Species

“…The fungal community associated with larval breeding water and mosquito guts and carcasses was dominated by the phyla Ascomycota and Basidiomycota, consistent with data reported in Ae. albopictus mosquito larvae collected in Manhattan, KS (Tawidian et al, 2021) and Aedes mosquito adults and larvae collected from the field (Muturi et al, 2016;Luis et al, 2019;Zouache et al, 2022). The observed phylum dominance was not surprising given the high prevalence of fungi in the phyla Ascomycota and Basidiomycota in habitats where mosquito larvae reside (Shelomi, 2019;Tawidian et al, 2021;Udujih Obinna Godwin et al, 2021;Zouache et al, 2022).…”

“…albopictus mosquito larvae collected in Manhattan, KS (Tawidian et al, 2021) and Aedes mosquito adults and larvae collected from the field (Muturi et al, 2016;Luis et al, 2019;Zouache et al, 2022). The observed phylum dominance was not surprising given the high prevalence of fungi in the phyla Ascomycota and Basidiomycota in habitats where mosquito larvae reside (Shelomi, 2019;Tawidian et al, 2021;Udujih Obinna Godwin et al, 2021;Zouache et al, 2022). In addition, it can also be attributed to the amplification bias of the ITS2 primers (fITS7 and ITS4) toward fungi belonging to these phyla with low affinity for early-diverging fungal lineages, e.g., including taxa in the Chytridiomycota (Bellemain et al, 2010;Blaalid et al, 2013;Bokulich and Mills, 2013).…”

“…albopictus and Ae. aegypti larvae reflect those in the larval breeding site (Tawidian et al, 2021;Zouache et al, 2022). In addition, tissue-specific fungal communities were observed in Ae.…”

“…albopictus and Ae. aegypti larvae (Tawidian et al, 2021;Zouache et al, 2022). However, it remains unclear whether similar patterns in fungal community assembly are observed in the larvae of other mosquito species.…”

Cryopreservation of mosquito microbiota for use in microcosm experiments

“…13.499917 doi: bioRxiv preprint then demonstrated the utility of this approach to study the factors shaping microbiome acquisition and assembly in mosquitoes and the mechanisms by which specific microbial taxa and assemblages contribute to different mosquito traits under controlled conditions (55). However, while these results highlight the value of expanding tools to manipulate the microbiota in mosquitoes, important questions remain regarding (i) the utility of microbiome transplantation approaches to establish reproducible communities in mosquito larval rearing environments, which harbor microbial communities that are much more complex than those in adult mosquitoes (5,8,52,(56)(57)(58)(59)(60)(61)(62), and (ii) how microbiota transplantation efficacy may be shaped by long-term preservation of donor microbial communities (e.g., via cryogenic freezing), which is absolutely necessary to facilitate long-term studies and intra-and interlaboratory comparisons but may introduce additional variability via impacts on bacterial viability and recovery (63)(64)(65)(66)(67)(68).…”