Browsing by Subject "Culex pipiens"

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    A Conserved Female-Specific Requirement for the GGT Gene in Mosquito Larvae Facilitates RNAi-Mediated Sex Separation in Multiple Species of Disease Vector Mosquitoes
    (MDPI, 2022-01-27) Mysore, Keshava; Sun, Longhua; Li, Ping; Roethele, Joseph B.; Misenti, Joi K.; Kosmach, John; Igiede, Jessica; Duman-Scheel, Molly; Medical and Molecular Genetics, School of Medicine
    Although several emerging mosquito control technologies are dependent on mass releases of adult males, methods of sex-sorting that can be implemented globally have not yet been established. RNAi screens led to the discovery of siRNA, which targets gamma-glutamyl transpeptidase (GGT), a gene which is well conserved in multiple species of mosquitoes and located at the sex-determining M locus region in Aedes aegypti. Silencing the A. aegypti, Aedes albopictus, Anopheles gambiae, Culex pipiens, and Culex quinquefasciatus GGT genes resulted in female larval death, with no significant impact on male survival. Generation of yeast strains that permitted affordable expression and oral delivery of shRNA corresponding to mosquito GGT genes facilitated larval target gene silencing and generated significantly increased 5 males:1 female adult ratios in each species. Yeast targeting a conserved sequence in Culex GGT genes was incorporated into a larval mass-rearing diet, permitting the generation of fit adult male C. pipiens and C. quinquefasciatus, two species for which labor-intensive manual sex separation had previously been utilized. The results of this study indicate that female-specific yeast-based RNAi larvicides may facilitate global implementation of population-based control strategies that require releases of sterile or genetically modified adult males, and that yeast RNAi strategies can be utilized in various species of mosquitoes that have progressed to different stages of sex chromosome evolution.
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    Culex pipiens and Culex restuans larval interactions shape the bacterial communities in container aquatic habitats
    (Oxford University Press, 2024-02-12) Njoroge, Teresia M.; Berenbaum, May R.; Stone, Christopher M.; Kim, Chang-Hyun; Dunlap, Christopher; Muturi, Ephantus J.; Medical and Molecular Genetics, School of Medicine
    Container aquatic habitats host a community of aquatic insects, primarily mosquito larvae that browse on container surface microbial biofilm and filter-feed on microorganisms in the water column. We examined how the bacterial communities in these habitats respond to feeding by larvae of two container-dwelling mosquito species, Culex pipiens and Cx. restuans. We also investigated how the microbiota of these larvae is impacted by intra- and interspecific interactions. Microbial diversity and richness were significantly higher in water samples when mosquito larvae were present, and in Cx. restuans compared to Cx. pipiens larvae. Microbial communities of water samples clustered based on the presence or absence of mosquito larvae and were distinct from those of mosquito larvae. Culex pipiens and Cx. restuans larvae harbored distinct microbial communities when reared under intraspecific conditions and similar microbial communities when reared under interspecific conditions. These findings demonstrate that mosquito larvae play a major role in structuring the microbial communities in container habitats and that intra- and interspecific interactions in mosquito larvae may shape their microbiota. This has important ecological and public health implications since larvae of the two mosquito species are major occupants of container habitats while the adults are vectors of West Nile virus.