[Observations on mortality and follicle size of Culex pipiens pipiens in the course of hibernation (author's transl)].
1
Citation
0
Reference
10
Related Paper
Keywords:
Hibernation
Culex pipiens
Course (navigation)
Cite
Hibernation
Culex pipiens
Course (navigation)
Cite
Citations (1)
The inadequacy of standard mosquito control strategies calls for ecologically safe novel approaches, for example the use of biological agents such as the endosymbiotic α-proteobacteria Wolbachia or insect-specific viruses (ISVs). Understanding the ecological interactions between these "biocontrol endosymbionts" is thus a fundamental step. Wolbachia are transmitted vertically from mother to offspring and modify their hosts' phenotypes, including reproduction (e.g., cytoplasmic incompatibility) and survival (e.g., viral interference). In nature, Culex pipiens (sensu lato) mosquitoes are always found infected with genetically diverse Wolbachia called wPip that belong to five phylogenetic groups. In recent years, ISVs have also been discovered in these mosquito species, although their interactions with Wolbachia in nature are unknown. Here, we studied the interactions between a widely prevalent ISV, the Culex pipiens densovirus (CpDV, Densovirinae), and Wolbachia in northern Tunisian C. pipiens populations. We showed an influence of different Wolbachia groups on CpDV prevalence and a general positive correlation between Wolbachia and CpDV loads. By investigating the putative relationship between CpDV diversification and wPip groups in the different sites, we detected a signal linked to wPip groups in CpDV phylogeny in sites where all larvae were infected by the same wPip group. However, no such signal was detected where the wPip groups coexisted, suggesting CpDV horizontal transfer between hosts. Overall, our results provide good evidence for an ecological influence of Wolbachia on an ISV, CpDV, in natural populations and highlight the importance of integrating Wolbachia in our understanding of ISV ecology in nature.
Culex pipiens
Cite
Citations (16)
Journal Article Boll Weevils: Time of Entry into Hibernation Sites and Variations in Survival and Emergence Get access H. M. Taft, H. M. Taft Entomology Research Division, Agric. Res. Serv., USDA, Florence, South Carolina 29501 Search for other works by this author on: Oxford Academic PubMed Google Scholar A. R. Hopkins, A. R. Hopkins Entomology Research Division, Agric. Res. Serv., USDA, Florence, South Carolina 29501 Search for other works by this author on: Oxford Academic PubMed Google Scholar W. James, W. James Entomology Research Division, Agric. Res. Serv., USDA, Florence, South Carolina 29501 Search for other works by this author on: Oxford Academic PubMed Google Scholar R. F. Moore, Jr. R. F. Moore, Jr. Entomology Research Division, Agric. Res. Serv., USDA, Florence, South Carolina 29501 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 66, Issue 1, 1 February 1973, Pages 254–256, https://doi.org/10.1093/jee/66.1.254 Published: 01 February 1973 Article history Received: 09 May 1972 Published: 01 February 1973
Entomology
Hibernation
Cite
Citations (3)
Gene duplications have long been advocated to contribute to the evolution of new functions. The role of selection in their early spread is more controversial. Unless duplications are favored for a direct benefit of increased expression, they are likely detrimental. In this article, we investigated the case of duplications favored because they combine already functionally divergent alleles. Their gene-dosage/fitness relations are poorly known because selection may operate on both overall expression and duplicates relative dosage. Using the well-documented case of Culex pipiens resistance to insecticides, we compared strains with various ace-1 allele combinations, including two duplicated alleles carrying both susceptible and resistant copies. The overall protein activity was nearly additive, but, surprisingly, fitness correlated better with the relative proportion of susceptible and resistant copies rather than any absolute measure of activity. Gene dosage is thus crucial, duplications stabilizing a "heterozygote" phenotype. It corroborates the view that these were favored because they fix a permanent heterosis, thereby solving the irreducible trade-off between resistance and synaptic transmission. Moreover, we showed that the contrasted successes of the two duplicated alleles in natural populations depend on genetic changes unrelated to ace-1, confirming the probable implication of recessive sublethal mutations linked to structural rearrangements in some duplications.
Culex pipiens
Gene dosage
Heterozygote advantage
Cite
Citations (33)
Culex pipiens
Esterase
Cite
Citations (14)
Culex pipiens pipiens plays an important role in the transmission of several vector-borne pathogens such as West Nile virus (WNV) in North America. Laboratory and field studies suggest that this species is ornithophilic but because of genetic hybridization with sibling species during the active mosquito season, it may occasionally feed on mammals. Adult female Cx. p. pipiens undergo a facultative diapause and may serve as an overwintering mechanism for WNV. To determine the effect of diapause on the innate host preference of Cx. p. pipiens emerging from winter hibernation, we conducted host-choice experiments using bird and mammal hosts. Mosquitoes were reared under non-diapause induced (NDI), diapause induced (DI), and field collected from overwintering (OW) hibernaculae. They were released into a large mesh enclosure housing two lard can traps, and given a choice between feeding on a dove or a rat. Host seeking Cx. p. pipiens were four times more likely to feed on the dove than the rat, regardless of experimental conditions. Under NDI conditions, Cx. p. pipiens were (p < 0.001) more attracted to the bird (79.9 % [75.6-84.1]) than the rat (20.1 [15.9-24.4]). Overwintering mosquitoes and those exposed to DI conditions were also significantly (p < 0.001) more attracted to birds (81.6 % [75.9-87.3]) than to rats (18.5 [12.7-24.2]). We provide new information about the innate host preference of Cx. p. pipiens emerging from diapause in temperate habitats where winter survival is crucial for disease transmission cycles. Although we showed that Cx. p. pipiens prefers an avian to a mammalian host, nearly 20 % of emerging mosquitoes in the spring could feed on mammals. Changes in host preferences may also contain valuable clues about transmission dynamics and subsequent timely interventions by vector control and public health practitioners.
Overwintering
Culex pipiens
Hibernation
Facultative
Cite
Citations (34)
The α-proteobacteria Wolbachia are among the most common intracellular bacteria and have recently emerged as important drivers of arthropod biology. Wolbachia commonly act as reproductive parasites in arthropods by inducing cytoplasmic incompatibility (CI), a type of conditional sterility between hosts harboring incompatible infections. In this study, we examined the evolutionary histories of Wolbachia infections, known as wPip, in the common house mosquito Culex pipiens, which exhibits the greatest variation in CI crossing patterns observed in any insect. We first investigated a panel of 20 wPip strains for their genetic diversity through a multilocus scheme combining 13 Wolbachia genes. Because Wolbachia depend primarily on maternal transmission for spreading within arthropod populations, we also studied the variability in the coinherited Cx. pipiens mitochondria. In total, we identified 14 wPip haplotypes, which all share a monophyletic origin and clearly cluster into five distinct wPip groups. The diversity of Cx. pipiens mitochondria was extremely reduced, which is likely a consequence of cytoplasmic hitchhiking driven by a unique and recent Wolbachia invasion. Phylogenetic evidence indicates that wPip infections and mitochondrial DNA have codiverged through stable cotransmission within the cytoplasm and shows that a rapid diversification of wPip has occurred. The observed pattern demonstrates that a considerable degree of Wolbachia diversity can evolve within a single host species over short evolutionary periods. In addition, multiple signatures of recombination were found in most wPip genomic regions, leading us to conclude that the mosaic nature of wPip genomes may play a key role in their evolution.
Cytoplasmic incompatibility
Culex pipiens
Monophyly
Cite
Citations (138)
Hibernation
Culex pipiens
Cite
Citations (2)
Journal Article Characterization of a Novel High-Activity Esterase in Tunisian Populations of the Mosquito Culex pipiens Get access Raja Ben Cheikh, Raja Ben Cheikh 1Institut des Sciences de I’Evolution (UM2, CNRS), Equipe Gènètique de I’Adaptation, Universitè Montpellier 2 (C.C. 065), 34095 Montpellier, France.2Laboratoire de Gènètique, Facultè de Mèdecine de Monastir, Universitè de Monastir, 5019 Monastir, Tunisia. Search for other works by this author on: Oxford Academic PubMed Google Scholar Claire Berticat, Claire Berticat 1Institut des Sciences de I’Evolution (UM2, CNRS), Equipe Gènètique de I’Adaptation, Universitè Montpellier 2 (C.C. 065), 34095 Montpellier, France. Search for other works by this author on: Oxford Academic PubMed Google Scholar Arnaud Berthomieu, Arnaud Berthomieu 1Institut des Sciences de I’Evolution (UM2, CNRS), Equipe Gènètique de I’Adaptation, Universitè Montpellier 2 (C.C. 065), 34095 Montpellier, France. Search for other works by this author on: Oxford Academic PubMed Google Scholar Nicole Pasteur, Nicole Pasteur 1Institut des Sciences de I’Evolution (UM2, CNRS), Equipe Gènètique de I’Adaptation, Universitè Montpellier 2 (C.C. 065), 34095 Montpellier, France. Search for other works by this author on: Oxford Academic PubMed Google Scholar Hassen Ben Cheikh, Hassen Ben Cheikh 2Laboratoire de Gènètique, Facultè de Mèdecine de Monastir, Universitè de Monastir, 5019 Monastir, Tunisia. Search for other works by this author on: Oxford Academic PubMed Google Scholar Mylène Weill Mylène Weill 3 1Institut des Sciences de I’Evolution (UM2, CNRS), Equipe Gènètique de I’Adaptation, Universitè Montpellier 2 (C.C. 065), 34095 Montpellier, France. 3Corresponding author, e-mail: weill@isem.univ-montp2.fr Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 101, Issue 2, 1 April 2008, Pages 484–491, https://doi.org/10.1093/jee/101.2.484 Published: 26 September 2014 Article history Received: 12 September 2007 Accepted: 31 October 2007 Published: 26 September 2014
Cite
Citations (7)