Host-Pathogen Interactions and Resilience

@article{CF2024,

title = {Neofunctionalization driven by positive selection led to the retention of the loqs2 gene encoding an Aedes specific dsRNA binding protein},

author = {Estevez-Castro CF and Rodrigues MF and Babarit A and Ferreira FV and de Andrade EG and Marois E and Cogni R and Aguiar ERGR and Marques JT and Olmo RP},

url = {https://doi.org/10.1186/s12915-024-01821-4},

doi = {10.1186/s12915-024-01821-4},

year  = {2024},

date = {2024-01-25},

urldate = {2024-01-25},

journal = {BMC Biol },

volume = {22},

number = {14},

abstract = {Background

Mosquito borne viruses, such as dengue, Zika, yellow fever and Chikungunya, cause millions of infections every year. These viruses are mostly transmitted by two urban-adapted mosquito species, Aedes aegypti and Aedes albopictus. Although mechanistic understanding remains largely unknown, Aedes mosquitoes may have unique adaptations that lower the impact of viral infection. Recently, we reported the identification of an Aedes specific double-stranded RNA binding protein (dsRBP), named Loqs2, that is involved in the control of infection by dengue and Zika viruses in mosquitoes. Preliminary analyses suggested that the loqs2 gene is a paralog of loquacious (loqs) and r2d2, two co-factors of the RNA interference (RNAi) pathway, a major antiviral mechanism in insects.

Results

Here we analyzed the origin and evolution of loqs2. Our data suggest that loqs2 originated from two independent duplications of the first double-stranded RNA binding domain of loqs that occurred before the origin of the Aedes Stegomyia subgenus, around 31 million years ago. We show that the loqs2 gene is evolving under relaxed purifying selection at a faster pace than loqs, with evidence of neofunctionalization driven by positive selection. Accordingly, we observed that Loqs2 is localized mainly in the nucleus, different from R2D2 and both isoforms of Loqs that are cytoplasmic. In contrast to r2d2 and loqs, loqs2 expression is stage- and tissue-specific, restricted mostly to reproductive tissues in adult Ae. aegypti and Ae. albopictus. Transgenic mosquitoes engineered to express loqs2 ubiquitously undergo developmental arrest at larval stages that correlates with massive dysregulation of gene expression without major effects on microRNAs or other endogenous small RNAs, classically associated with RNA interference.

Conclusions

Our results uncover the peculiar origin and neofunctionalization of loqs2 driven by positive selection. This study shows an example of unique adaptations in Aedes mosquitoes that could ultimately help explain their effectiveness as virus vectors.},

keywords = {Aedes mosquitoes, Double-stranded RNA (dsRNA), dsRNA binding protein (dsRBP), loqs2, M3i, marois, Marques, Olmo, RNA interference (RNAi)},

pubstate = {published},

tppubtype = {article}

}

@article{Green2024,

title = {A population modification gene drive targeting both Saglin and Lipophorin disables Plasmodium transmission in Anopheles mosquitoes},

author = {Emily I Green and Etienne Jaouen and Dennis Klug and Roenick Proveti Olmo and Amandine Gautier and Stéphanie Blandin and Eric Marois},

url = {https://elifesciences.org/articles/93142},

doi = {10.7554/eLife.93142},

year  = {2024},

date = {2024-01-12},

journal = {Genetics and Genomics},

abstract = {Lipophorin is an essential, highly expressed lipid transport protein that is secreted and circulates in insect hemolymph. We hijacked the Anopheles coluzzii Lipophorin gene to make it co-express a single-chain version of antibody 2A10, which binds sporozoites of the malaria parasite Plasmodium falciparum. The resulting transgenic mosquitoes show a markedly decreased ability to transmit Plasmodium berghei expressing the P. falciparum circumsporozoite protein to mice. To force the spread of this antimalarial transgene in a mosquito population, we designed and tested several CRISPR/Cas9-based gene drives. One of these is installed in, and disrupts, the pro-parasitic gene Saglin and also cleaves wild-type Lipophorin, causing the anti-malarial modified Lipophorin version to replace the wild type and hitch-hike together with the Saglin drive. Although generating drive-resistant alleles and showing instability in its gRNA-encoding multiplex array, the Saglin-based gene drive reached high levels in caged mosquito populations and efficiently promoted the simultaneous spread of the antimalarial Lipophorin::Sc2A10 allele. This combination is expected to decrease parasite transmission via two different mechanisms. This work contributes to the design of novel strategies to spread antimalarial transgenes in mosquitoes, and illustrates some expected and unexpected outcomes encountered when establishing a population modification gene drive.},

keywords = {Anopheles, blandin, gene drive, Lipophorin, M3i, marois, marque, Marques, Olmo, Plasmodium, Saglin},

pubstate = {published},

tppubtype = {article}

}

@article{Abbo2023,

title = {The virome of the invasive Asian bush mosquito Aedes japonicus in Europe},

author = {Abbo SR and de Almeida JPP and Olmo RP and Balvers C and Griep JS and Linthout C and Koenraadt CJM and Silva BM and Fros JJ and Aguiar ERGR and Marois E and Pijlman GP and Marques JT},

doi = {10.1093/ve/vead041},

year  = {2023},

date = {2023-09-22},

urldate = {2023-09-22},

journal = {Virus Evol.},

volume = {9},

issue = {2},

abstract = {The Asian bush mosquito Aedes japonicus is rapidly invading North America and Europe. Due to its potential to transmit multiple pathogenic arthropod-borne (arbo)viruses including Zika virus, West Nile virus, and chikungunya virus, it is important to understand the biology of this vector mosquito in more detail. In addition to arboviruses, mosquitoes can also carry insect-specific viruses that are receiving increasing attention due to their potential effects on host physiology and arbovirus transmission. In this study, we characterized the collection of viruses, referred to as the virome, circulating in Ae. japonicus populations in the Netherlands and France. Applying a small RNA-based metagenomic approach to Ae. japonicus, we uncovered a distinct group of viruses present in samples from both the Netherlands and France. These included one known virus, Ae. japonicus narnavirus 1 (AejapNV1), and three new virus species that we named Ae. japonicus totivirus 1 (AejapTV1), Ae. japonicus anphevirus 1 (AejapAV1) and Ae. japonicus bunyavirus 1 (AejapBV1). We also discovered sequences that were presumably derived from two additional novel viruses: Ae. japonicus bunyavirus 2 (AejapBV2) and Ae. japonicus rhabdovirus 1 (AejapRV1). All six viruses induced strong RNA interference responses, including the production of twenty-one nucleotide-sized small interfering RNAs, a signature of active replication in the host. Notably, AejapBV1 and AejapBV2 belong to different viral families; however, no RNA-dependent RNA polymerase sequence has been found for AejapBV2. Intriguingly, our small RNA-based approach identified an ∼1-kb long ambigrammatic RNA that is associated with AejapNV1 as a secondary segment but showed no similarity to any sequence in public databases. We confirmed the presence of AejapNV1 primary and secondary segments, AejapTV1, AejapAV1, and AejapBV1 by reverse transcriptase polymerase chain reaction (PCR) in wild-caught Ae. japonicus mosquitoes. AejapNV1 and AejapTV1 were found at high prevalence (87-100 per cent) in adult females, adult males, and larvae. Using a small RNA-based, sequence-independent metagenomic strategy, we uncovered a conserved and prevalent virome among Ae. japonicus mosquito populations. The high prevalence of AejapNV1 and AejapTV1 across all tested mosquito life stages suggests that these viruses are intimately associated with Ae. japonicus.},

keywords = {Aedes japonicus, anphevirus, bunyavirus, M3i, marois, Marques, metagenomics, mosquito, Olmo, rhabdovirus, RNA Interference, totivirus, virome},

pubstate = {published},

tppubtype = {article}

}

@article{Lutrat2023,

title = {Combining two Genetic Sexing Strains allows sorting of non-transgenic males for Aedes genetic control},

author = {Lutrat C and Burckbuchler M and Olmo RP and Beugnon R and Fontaine A and Akbari OS and Argiles-Herrero R and Baldet T and Bouyer J and Marois E},

url = {https://www.nature.com/articles/s42003-023-05030-7},

doi = {10.1038/s42003-023-05030-7},

year  = {2023},

date = {2023-06-16},

urldate = {2023-06-16},

journal = {Commun Biol.},

volume = {6},

issue = {1},

pages = {646},

abstract = {Chemical control of disease vectoring mosquitoes Aedes albopictus and Aedes aegypti is costly, unsustainable, and increasingly ineffective due to the spread of insecticide resistance. The Sterile Insect Technique is a valuable alternative but is limited by slow, error-prone, and wasteful sex-separation methods. Here, we present four Genetic Sexing Strains (two for each Aedes species) based on fluorescence markers linked to the m and M sex loci, allowing for the isolation of transgenic males. Furthermore, we demonstrate how combining these sexing strains enables the production of non-transgenic males. In a mass-rearing facility, 100,000 first instar male larvae could be sorted in under 1.5 h with an estimated 0.01–0.1% female contamination on a single machine. Cost-efficiency analyses revealed that using these strains could result in important savings while setting up and running a mass-rearing facility. Altogether, these Genetic Sexing Strains should enable a major upscaling in control programmes against these important vectors.},

keywords = {Aedes, M3i, marois, mosquitoes, Olmo, vectoring},

pubstate = {published},

tppubtype = {article}

}

@article{Olmo.2023,

title = {Mosquito vector competence for dengue is modulated by insect-specific viruses},

author = {Olmo R.P. and Todjro Y.M.H. and Aguiar E.R.G.R. and de Almeida J.P.P. and Ferreira F.V. and Armache J.N. and de Faria I.J.S. and Ferreira A.G.A. and Amadou S.C.D. and Silva A.T.S. and de Souza K.P.R. and Vilela A.P.P. and Babarit A. and Tan C.H. and Diallo M. and Gaye A. and Paupy C. and Obame-Nkoghe J. and Visser T.M. and Koenraadt C.J.M. and Wongsokarijo M.A. and Cruz A.L.C. and Prieto M.T. and Parra M.C.P. and Nogueira M.L., and Avelino-Silva V. and Mota R.N. and Borges M.A.Z. and Drumond B.P. and Kroon E.G. and Recker M. and Sedda L. and Marois E. and Imler J.L. and Marques J.T. },

url = {https://doi.org/},

doi = {10.1038/s41564-022-01289-4},

year  = {2023},

date = {2023-01-05},

urldate = {2023-01-05},

journal = {Nature Microbiology},

volume = {8},

issue = {1},

abstract = {Aedes aegypti and A. albopictus mosquitoes are the main vectors for dengue virus (DENV) and other arboviruses, including Zika virus (ZIKV). Understanding the factors that affect transmission of arboviruses from mosquitoes to humans is a priority because it could inform public health and targeted interventions. Reasoning that interactions among viruses in the vector insect might affect transmission, we analysed the viromes of 815 urban Aedes mosquitoes collected from 12 countries worldwide. Two mosquito-specific viruses, Phasi Charoen-like virus (PCLV) and Humaita Tubiacanga virus (HTV), were the most abundant in A. aegypti worldwide. Spatiotemporal analyses of virus circulation in an endemic urban area revealed a 200% increase in chances of having DENV in wild A. aegypti mosquitoes when both HTV and PCLV were present. Using a mouse model in the laboratory, we showed that the presence of HTV and PCLV increased the ability of mosquitoes to transmit DENV and ZIKV to a vertebrate host. By transcriptomic analysis, we found that in DENV-infected mosquitoes, HTV and PCLV block the downregulation of histone H4, which we identify as an important proviral host factor in vivo.},

keywords = {Dengue, imler, M3i, marois, Marques, mosquito, Olmo, virus},

pubstate = {published},

tppubtype = {article}

}