ORCID Profile
0000-0001-5958-2138
Current Organisations
Institut Pasteur
,
Centre National de la Recherche Scientifique
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Public Library of Science (PLoS)
Date: 07-10-2019
Publisher: Proceedings of the National Academy of Sciences
Date: 18-04-2011
Abstract: Most studies on the ability of insect populations to transmit pathogens consider only constant temperatures and do not account for realistic daily temperature fluctuations that can impact vector–pathogen interactions. Here, we show that diurnal temperature range (DTR) affects two important parameters underlying dengue virus (DENV) transmission by Aedes aegypti . In two independent experiments using different DENV serotypes, mosquitoes were less susceptible to virus infection and died faster under larger DTR around the same mean temperature. Large DTR (20 °C) decreased the probability of midgut infection, but not duration of the virus extrinsic incubation period (EIP), compared with moderate DTR (10 °C) or constant temperature. A thermodynamic model predicted that at mean temperatures °C, DENV transmission increases as DTR increases, whereas at mean temperatures °C, larger DTR reduces DENV transmission. The negative impact of DTR on Ae. aegypti survival indicates that large temperature fluctuations will reduce the probability of vector survival through EIP and expectation of infectious life. Seasonal variation in the litude of daily temperature fluctuations helps to explain seasonal forcing of DENV transmission at locations where average temperature does not vary seasonally and mosquito abundance is not associated with dengue incidence. Mosquitoes lived longer and were more likely to become infected under moderate temperature fluctuations, which is typical of the high DENV transmission season than under large temperature fluctuations, which is typical of the low DENV transmission season. Our findings reveal the importance of considering short-term temperature variations when studying DENV transmission dynamics.
Publisher: Public Library of Science (PLoS)
Date: 06-01-2022
DOI: 10.1371/JOURNAL.PPAT.1010202
Abstract: The exogenous small interfering RNA (exo-siRNA) pathway is a key antiviral mechanism in the Aedes aegypti mosquito, a widely distributed vector of human-pathogenic arboviruses. This pathway is induced by virus-derived double-stranded RNAs (dsRNA) that are cleaved by the ribonuclease Dicer 2 (Dcr2) into predominantly 21 nucleotide (nt) virus-derived small interfering RNAs (vsiRNAs). These vsiRNAs are used by the effector protein Argonaute 2 within the RNA-induced silencing complex to cleave target viral RNA. Dcr2 contains several domains crucial for its activities, including helicase and RNase III domains. In Drosophila melanogaster Dcr2, the helicase domain has been associated with binding to dsRNA with blunt-ended termini and a processive siRNA production mechanism, while the platform-PAZ domains bind dsRNA with 3’ overhangs and subsequent distributive siRNA production. Here we analyzed the contributions of the helicase and RNase III domains in Ae . aegypti Dcr2 to antiviral activity and to the exo-siRNA pathway. Conserved amino acids in the helicase and RNase III domains were identified to investigate Dcr2 antiviral activity in an Ae . aegypti -derived Dcr2 knockout cell line by reporter assays and infection with mosquito-borne Semliki Forest virus ( Togaviridae , Alphavirus ). Functionally relevant amino acids were found to be conserved in haplotype Dcr2 sequences from field-derived Ae . aegypti across different continents. The helicase and RNase III domains were critical for silencing activity and 21 nt vsiRNA production, with RNase III domain activity alone determined to be insufficient for antiviral activity. Analysis of 21 nt vsiRNA sequences (produced by functional Dcr2) to assess the distribution and phasing along the viral genome revealed erse yet highly consistent vsiRNA pools, with predominantly short or long sequence overlaps including 19 nt overlaps (the latter representing most likely true Dcr2 cleavage products). Combined with the importance of the Dcr2 helicase domain, this suggests that the majority of 21 nt vsiRNAs originate by processive cleavage. This study sheds new light on Ae . aegypti Dcr2 functions and properties in this important arbovirus vector species.
Publisher: Public Library of Science (PLoS)
Date: 08-03-2013
Publisher: Oxford University Press (OUP)
Date: 2013
DOI: 10.1603/ME11242
Abstract: Seasonal variation in dengue virus transmission in northwestern Thailand is inversely related to the magnitude of diurnal temperature fluctuations, although mean temperature does not vary significantly across seasons. We tested the hypothesis that diurnal temperature fluctuations negatively influence epidemiologically important life-history traits of the primary dengue vector, Aedes aegypti (L.), compared with a constant 26 degrees C temperature. A large diurnal temperature range (DTR) (approximately equals 18 degrees C daily swing) extended immature development time (>1 d), lowered larval survival (approximately equals 6%), and reduced adult female reproductive output by 25% 14 d after blood feeding, relative to the constant 26 degreesC temperature. A small DTR (approximately equal 8 degrees C daily swing) led to a negligible or slightly positive effect on the life history traits tested. Our results indicate that there is a negative impact of large DTR on mosquito biology and are consistent with the hypothesis that, in at least some locations, large temperature fluctuations contribute to seasonal reduction in dengue virus transmission.
Publisher: American Society of Tropical Medicine and Hygiene
Date: 03-04-2013
Publisher: Public Library of Science (PLoS)
Date: 25-04-2013
Publisher: Oxford University Press (OUP)
Date: 09-2017
DOI: 10.1093/GBE/EVX171
Publisher: Springer Science and Business Media LLC
Date: 08-04-2019
DOI: 10.1038/S41564-019-0440-7
Abstract: This Article was mistakenly not made Open Access when originally published this has now been amended, and information about the Creative Commons Attribution 4.0 International License has been added into the ‘Additional information’ section.
Publisher: Springer Science and Business Media LLC
Date: 04-03-2019
DOI: 10.1038/S41564-019-0376-Y
Abstract: The global population at risk from mosquito-borne diseases—including dengue, yellow fever, chikungunya and Zika—is expanding in concert with changes in the distribution of two key vectors: Aedes aegypti and Aedes albopictus . The distribution of these species is largely driven by both human movement and the presence of suitable climate. Using statistical mapping techniques, we show that human movement patterns explain the spread of both species in Europe and the United States following their introduction. We find that the spread of Ae. aegypti is characterized by long distance importations, while Ae. albopictus has expanded more along the fringes of its distribution. We describe these processes and predict the future distributions of both species in response to accelerating urbanization, connectivity and climate change. Global surveillance and control efforts that aim to mitigate the spread of chikungunya, dengue, yellow fever and Zika viruses must consider the so far unabated spread of these mosquitos. Our maps and predictions offer an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.
Publisher: Cold Spring Harbor Laboratory
Date: 15-03-2023
DOI: 10.1101/2023.03.13.532092
Abstract: Domestication is a complex, multi-stage and species-specific process that results in organisms living close to humans. In the arboviral vector Aedes aegypti adaptation to living in proximity with anthropogenic environments has been recognized as a major evolutionary shift, separating a generalist form, Aedes aegypti formosus (Aaf), from the domestic form Aedes aegypti aegypti (Aaa), which tends to deposit eggs artificial containers and bite humans for a blood meal. These behaviors enhance the mosquito vectorial capacity. The extent to which domestication has impacted the Ae. aegypti genome has not been thoroughly investigated yet. Taking advantage of two forms’ distinct and historically documented geographic distributions, we analyzed the genomes of 634 worldwide Ae. aegypti mosquitoes. Using more than 300 million high-confidence SNPs, we found a unique origin for all out-of-Africa Ae. aegypti mosquitoes, with no evidence of admixture events in Africa, apart from Kenya. A group of genes were under positive selection only in out-of-Africa mosquitoes and 236 genes had nonsynonymous mutations, occurring at statistically different frequencies in Aaa and Aaf mosquitoes. We identified a clear signal of genetic differentiation between Aaa and Aaf, circumscribed to a catalogue of candidate genes. These “ Aaa molecular signature ” genes extend beyond chemosensory genes to genes linked to neuronal and hormonal functions. This suggests that the behavioral shift to domestication may rely on the fine regulation of metabolic and neuronal functions, more than the role of a few significant genes. Our results also provide the foundation to investigate new targets for the control of Ae. aegypti populations.
Publisher: Informa UK Limited
Date: 26-10-2021
Publisher: Informa UK Limited
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 21-03-2019
DOI: 10.1038/S41564-019-0429-2
Abstract: In the version of this Article originally published, the affiliation for author Catherine Linard was incorrectly stated as ‘ 6 Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK’. The correct affiliation is ‘ 9 Spatial Epidemiology Lab (SpELL), Universite Libre de Bruxelles, Brussels, Belgium’. The affiliation for author Hongjie Yu was also incorrectly stated as ‘ 11 Department of Statistics, Harvard University, Cambridge, MA, USA’. The correct affiliation is ‘ 15 School of Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China’. This has now been amended in all versions of the Article.
Publisher: Cold Spring Harbor Laboratory
Date: 29-12-2017
DOI: 10.1101/240747
Abstract: Female Aedes aegypti mosquitoes infect hundreds of millions of people each year with dangerous viral pathogens including dengue, yellow fever, Zika, and chikungunya. Progress in understanding the biology of this insect, and developing tools to fight it, has been slowed by the lack of a high-quality genome assembly. Here we combine erse genome technologies to produce AaegL5, a dramatically improved and annotated assembly, and demonstrate how it accelerates mosquito science and control. We anchored the physical and cytogenetic maps, resolved the size and composition of the elusive sex-determining “M locus”, significantly increased the known members of the glutathione-S-transferase genes important for insecticide resistance, and doubled the number of chemosensory ionotropic receptors that guide mosquitoes to human hosts and egg-laying sites. Using high-resolution QTL and population genomic analyses, we mapped new candidates for dengue vector competence and insecticide resistance. We predict that AaegL5 will catalyse new biological insights and intervention strategies to fight this deadly arboviral vector.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-11-2020
Abstract: Why hasn't Zika virus (ZIKV) disease caused as much devastation in Africa, its continent of origin, as it has in the Americas? Outside of Africa, this flavivirus is transmitted by a ubiquitous mosquito subspecies, Aedes aegypti aegypti , which emerged from the African forerunner subspecies A. aegypti formosus and acquired a preference for human blood and a peridomestic lifestyle. Now, this subspecies colonizes many intertropical cities, aided by climate change and human trash. Aubry et al. tested 14 laboratory mosquito colonies for their relative susceptibility to ZIKV. Quantitative trait locus mapping showed differences on chromosome 2 between mosquitoes from Gabon and Guadeloupe. Mouse infection experiments revealed that African mosquitoes transmitted a smaller virus inoculum than the South American insects. Increased susceptibility coupled with the ability of A. aegypti aegypti to breed in any discarded object containing water has lified the problematic nature of this virus as it has circumnavigated the world. Science , this issue p. 991
Publisher: Springer Science and Business Media LLC
Date: 11-2018
Publisher: Elsevier BV
Date: 07-2015
No related grants have been discovered for Louis Lambrechts.