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LAMBRECHTS, L.

Publications and source records attributed to LAMBRECHTS, L..

6 recordsLinked to original sources

Deep behavioral phenotyping of pathogen infected mosquitoes reveals species-specific behavior changes enhancing transmission

Mosquito-borne pathogens are often proposed to alter mosquito behavior to enhance transmission, yet the prevalence, magnitude, and consequences of such effects remain unclear. Using custom high- throughput behavioral assays and deep-learning analysis, we quantified the blood-feeding behavior of more than 5,000 mosquitoes, and long-term activity patterns of more than 1,000 mosquitoes across six clinically relevant mosquito-pathogen combinations. Infection effects were highly species-specific. Anopheles stephensi infected with an African Plasmodium falciparum strain showed elevated flight activity throughout infection, an increased tendency to blood-feed upon host contact, and prolonged feeding times. In contrast, infection with an Asian P. falciparum strain or P. vivax had little impact on An. stephensi behavior. We detected no behavioral changes associated with P. falciparum infection in Anopheles gambiae s.s. or Anopheles coluzzii. Interestingly, dengue virus infection in Aedes aegypti increased landing, probing, and engorgement rates. Together, these results demonstrate that infection-induced behavioral change is not a general phenomenon among mosquito-borne pathogens, yet differs markedly per mosquito and pathogen species. A transmission model parameterized with our data showed that even modest behavioral shifts can substantially increase transmission, underscoring the potential epidemiological importance of subtle phenotypic shifts.

animal behavior and cognition↗

A targeted amplicon sequencing panel for cost-effective high-throughput genotyping of Aedes aegypti

The mosquito Aedes aegypti is the primary vector for several medically significant arboviruses, including dengue, Zika, chikungunya, and yellow fever. Studying the genetic diversity of Ae. aegypti is crucial for understanding its evolutionary history, population dynamics, and the effectiveness of vector control methods. Due to the large genome size of Ae. aegypti, whole-genome sequencing (WGS) is often cost-prohibitive for large-scale studies. Recent advances in reduced-representation methods, aiming to reduce costs by sequencing only a small portion of the genome, provide cost-effective alternatives. However, a standardized set of genome-wide markers specifically designed for population genetic studies of Ae. aegypti remains unavailable. Here, we present a targeted amplicon sequencing panel designed for cost-effective, high-throughput genotyping across 291 loci distributed throughout the Ae. aegypti genome. Our in silico analyses indicate that this amplicon panel effectively replicates population structure analyses typically derived from WGS data. We demonstrate that the amplicon panel accurately discriminates between diverse laboratory colonies of Ae. aegypti and consistently measures individual genetic admixture to a degree comparable with WGS. By enabling high-throughput genotyping at a reduced cost, we anticipate that our targeted amplicon sequencing panel will facilitate large-scale genotyping studies of Ae. aegypti for vector surveillance and population structure analyses, especially in resource-limited settings.

genomics↗

A Vago-like gene enhances dengue and Zika virus dissemination in Aedes aegypti

Arthropod-borne viruses (arboviruses) such as dengue virus (DENV) and Zika virus (ZIKV) pose a significant threat to global health. Novel approaches to control the spread of arboviruses focus on harnessing the antiviral immune system of their primary vector, the Aedes aegypti mosquito. In arthropods, genes of the Vago family are often presented as analogs of mammalian cytokines with potential antiviral functions, but the role of Vago genes upon virus infection in Ae. aegypti is largely unknown. We conducted a phylogenetic analysis of the Vago gene family in Diptera, which led us to focus on a Vago-like gene that we named VLG-1. Using CRISPR/Cas9-mediated gene editing, we generated a VLG-1 mutant line of Ae. aegypti, which revealed a broad impact of VLG-1 on the mosquito transcriptome, affecting several biological processes potentially related to viral replication, including the oxidative stress response. Surprisingly, experimental viral challenge of the VLG-1 mutant line indicated a modest proviral role for this gene during DENV and ZIKV infections in vivo. In the absence of VLG-1, virus dissemination throughout the mosquitos body was slightly impaired, albeit not altering virus transmission rates. Our results challenge the conventional understanding of Vago-like genes as antiviral factors and underscore the need for further in vivo research to elucidate the molecular mechanisms underlying mosquito-arbovirus interactions.

immunology↗

Atypical landscape of transposable elements in the large genome of Aedes aegypti

Transposable elements (TEs) contribute significantly to variation in genome size among eukaryotic species, but the factors influencing TE accumulation and diversification are only partially understood. Most of our current knowledge about TE organization, dynamics and evolution derives from investigations in model organisms with a relatively small genome size such as Drosophila melanogaster or Arabidopsis thaliana. Whether the observed patterns hold true in larger genomes remains to be determined. The Diptera order is an ideal taxon to address this question, because it includes a forty-year model of TE biology (D. melanogaster) as well as mosquito species with significantly larger genomes. Here, we use a comparative genomics approach to characterize the genomic forces that have shaped the TE content of the Aedes aegypti genome (1.3 Gb) relative to the Anopheles coluzzii genome (300 Mb) and the D. melanogaster genome (180 Mb). Leveraging a newly developed high-quality TE library for Ae. aegypti, our results reveal a contrasted pattern of TE organization in Ae. aegypti compared to An. coluzzii and D. melanogaster. Our analyses suggest that the substantial TE fraction observed in the Ae. aegypti genome reflect both a high rate of TE transposition and a low rate of TE elimination. Together, our results indicate that TE organization and evolutionary dynamics in the large genome of Ae. aegypti are distinct from those of other dipterans with smaller genomes.

evolutionary biology↗

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↗

Tudor-SN promotes early replication of dengue virus in the Aedes aegypti midgut

Diseases caused by mosquito-borne viruses have been on the rise for the last decades, despite the implementation of vector control methods primarily based on insecticides. An alternative control method currently in development is the use of lab-engineered mosquitoes that are incapable to carry viruses. This has stimulated efforts to identify optimal target genes that are naturally involved in mosquito antiviral defenses or required for viral replication. Although several antiviral immune pathways such as RNA interference (RNAi) have been previously characterized in mosquitoes, the genes that prevent or promote early viral replication in the midgut remain elusive. Here, we investigated the role of a member of the Tudor protein family, Tudor-SN, upon dengue virus infection in the mosquito Aedes aegypti. Tudor-SN expression was upregulated early after dengue virus infection and was subsequently positively correlated with viral loads in the midgut. Using RNAi-mediated knockdown, we showed that the loss of Tudor-SN reduced dengue virus replication in the Ae. aegypti derived cell line Aag2 and in the midgut of Ae. aegypti females in vivo. Using immunofluorescence assays, we found that Tudor-SN localizes to the nucleolus in both Ae. aegypti and Aedes albopictus cells. Finally, we used a reporter assay to demonstrate that Tudor-SN was not required for RNAi function in vivo. Collectively, these results define a novel proviral role for Tudor-SN upon early dengue virus infection of the Ae. aegypti midgut.

microbiology↗