Biology subjects

Valiente Moro, C.

Publications and source records attributed to Valiente Moro, C..

5 recordsLinked to original sources

bioRxiv2026

From urban runoff to mosquito success : spatiotemporal microbial assembly in larval water habitats under anthropogenic stressors

Urban mosquito habitats are heterogeneous aquatic ecosystems where anthropogenic inputs shape physicochemical conditions and microbial community assembly. However, the combined effects of environmental chemistry and microbial dynamics on mosquito fitness remain poorly understood across space and time. Here, we integrated environmental chemistry, metabarcoding, and experimental assays to investigate how spatiotemporal variation in urban larval habitats influences environmental microbial assembly and the biology of the Asian tiger mosquito, Aedes albopictus. Six stormwater drains were monitored over five months to characterize ions, dissolved gases, micropollutants, and bacterial and fungal communities. Laboratory assays using water from three contrasting habitats were then conducted to evaluate oviposition preference and mosquito performance. Microbial community composition was strongly structured by breeding-site identity and associated with distinct physicochemical signatures. Bacterial communities remained relatively stable over time, whereas fungal assemblages exhibited stronger temporal turnover. These environmental differences translated into marked variation in larval performance, ranging from rapid development and high survival to delayed development, reduced survival, and episodic cohort collapse under environmentally unstable conditions. Adult traits further revealed carry-over effects of larval environment exposure across life stages. Correlation analyses showed that mosquito fitness was associated with both abiotic variables and microbial taxa linked to larval survival, development, emergence, and adult longevity. In contrast, oviposition preference remained consistently high across habitats despite strong differences in offspring performance, indicating a decoupling between habitat attractiveness and suitability. Overall, our results demonstrate that anthropogenic stressors shape microbial assembly in urban larval habitats, with cascading consequences for mosquito fitness and population dynamics.

ecology↗

bioRxiv2025

Friend or foe: A mosquito parasite with mixed transmission mode displays mutualistic traits promoting oogenesis.

Mutualism is often selected in vertically transmitted symbionts due to their fitness interdependence with hosts. However, the evolution of mutualism remains unclear in symbionts using both vertical and horizontal transmission. In this study, we show that Ascogregarina taiwanensis, previously known as a weak horizontally transmitted parasite of the Asian tiger mosquito (Aedes albopictus), exhibits mutualistic traits that enhance mosquito reproduction. The symbiont improves embryogenesis and extends the egg-laying period while most females are pseudo-vertically transmitting symbiont oocysts to their progeny at oviposition sites. Dual transcriptomic analyses reveal that early oogenesis in infected females involves increased nitrogen metabolism in both partners, enhanced detoxification of blood waste, and activation of egg development pathways. These changes lead to improved assimilation of blood proteins essential for egg production. Our findings provide rare empirical evidence of a symbiont displaying both parasitic and mutualistic traits, offering new insights into the evolutionary dynamics of mixed-mode transmission symbioses. Significance StatementHow mutualism evolves from parasitism remains a central question in evolutionary biology, particularly for symbionts that combine vertical and horizontal transmission. We show that Ascogregarina taiwanensis, an Apicomplexan parasite previously known to be costly for developing Aedes albopictus mosquitoes, is also pseudo-vertically transmitted: most females release oocysts into the water during oviposition, exposing their offspring. Surprisingly, infection enhances host reproduction by promoting oogenesis through protein assimilation, leading to the production of larger larvae. Dual transcriptomic analyses reveal coordinated shifts in host and parasite metabolism, especially in nitrogen assimilation. Our findings provide rare evidence that mutualistic traits can emerge in a symbiont with mixed-mode transmission, offering new insights into the evolutionary transitions shaping host-microbe interactions.

evolutionary biology↗

bioRxiv2024

A major entomoparasite interferes with Chikungunya transmission by Aedes albopictus

The Asian tiger mosquito, Aedes albopictus, spreads diseases like Chikungunya and has caused outbreaks worldwide. Studies show that mosquitoes-associated microbes can affect how well they spread diseases. One of those microbes, the parasite As. taiwanensis, is common in older mosquito populations but rare in newer ones. We found that this parasite slows down the spread of Chikungunya within the mosquito and decreases its transmission rate by half. Unparasitized mosquitoes spread the virus more easily, suggesting that changes in mosquito microbes could impact disease outbreaks and public health.

microbiology↗

bioRxiv2023

Establishment and comparative genomics of a high-quality collection of mosquito-associated bacterial isolates -- MosAIC (Mosquito-Associated Isolate Collection)

Mosquitoes transmit medically important human pathogens, including viruses like dengue virus and parasites such as Plasmodium spp., the causative agent of malaria. Mosquito microbiomes are critically important for the ability of mosquitoes to transmit disease-causing agents. However, while large collections of bacterial isolates and genomic data exist for vertebrate microbiomes, the vast majority of work in mosquitoes to date is based on 16S rRNA gene amplicon data that provides limited taxonomic resolution and no functional information. To address this gap and facilitate future studies using experimental microbiome manipulations, we generated a bacterial Mosquito-Associated Isolate Collection (MosAIC) consisting of 392 bacterial isolates with extensive metadata and high-quality draft genome assemblies that are publicly available for use by the scientific community. MosAIC encompasses 142 species spanning 29 bacterial families, with members of the Enterobacteriaceae comprising 40% of the collection. Phylogenomic analysis of three genera, Enterobacter, Serratia, and Elizabethkingia, reveal lineages of mosquito-associated bacteria isolated from different mosquito species in multiple laboratories. Investigation into species pangenomes further reveals clusters of genes specific to these lineages, which are of interest for future work to identify functions underlying mosquito host association. Altogether, we describe the generation of a physical collection of mosquito-associated bacterial isolates, their genomic data, and analyses of selected groups in context of genome data from closely related isolates, providing a unique, highly valuable resource to investigate factors for bacterial colonisation and adaptation within mosquito hosts. Future efforts will expand the collection to include broader geographic and host species representation, especially from individuals collected from field populations, as well as other mosquito-associated microbes, including fungi, archaea, and protozoa.

microbiology↗

bioRxiv2021

Mosquito-bacteria interactions during larval development trigger metabolic changes with carry-over effects on adult fitness

In animals with distinct life stages such as holometabolous insects, adult phenotypic variation is often shaped by the environment of immature stages, including their interactions with microbes colonizing larval habitats. Such carry-over effects were previously observed for several adult traits of the mosquito Aedes aegypti after larval exposure to different bacteria, but the mechanistic underpinnings are unknown. Here, we investigated the molecular changes triggered by gnotobiotic larval exposure to different bacteria in Ae. aegypti. We initially screened a panel of 16 bacterial isolates from natural mosquito breeding sites to determine their ability to influence adult life-history traits. We subsequently focused on four bacterial isolates (belonging to Flavobacterium, Lysobacter, Paenibacillus, and Enterobacteriaceae) with significant carry-over effects on adult survival and found that they were associated with distinct transcriptomic profiles throughout mosquito development. Moreover, we detected carry-over effects at the level of gene expression for the Flavobacterium and Paenibacillus isolates. The most prominent transcriptomic changes in gnotobiotic larvae reflected a profound remodeling of lipid metabolism, which translated into phenotypic differences in lipid storage and starvation resistance at the adult stage. Together, our findings indicate that larval exposure to environmental bacteria trigger substantial physiological changes that impact adult fitness, uncovering a mechanism underlying carry-over effects of mosquito-bacteria interactions during larval development.

microbiology↗