High insecticide resistance resulting from insensitive acetylcholinesterase (AChE) has emerged in mosquitoes. A single mutation (G119S of the ace-1 gene) explains this high Culex pipiens and Anopheles gambiae. In order to provide better documentation gene effect G119S mutation, we present a three-dimension structure model AChE, showing that unique substitution is localized oxyanion hole, explaining insensitivity its interference with enzyme catalytic functions. As creates restriction site,...

Acetylcholinesterase (AChE) is the target of two major insecticide families, organophosphates (OPs) and carbamates. AChE insensitivity a frequent resistance mechanism in insects responsible mutations ace gene were identified Diptera, Drosophila melanogaster Musca domestica. However, for other insects, cloned by homology with does not code insensitive resistant individuals, indicating existence second locus. We loci genome Anopheles gambiae, one (ace–1) being new locus (ace–2) homologous to...

Gene duplication is thought to be the main potential source of material for evolution new gene functions. Several models have been proposed functions through duplication, most based on ancient events (Myr). We provide molecular evidence occurrence several (at least 3) independent duplications ace-1 locus in mosquito Culex pipiens, selected response insecticide pressure that probably occurred very recently (<40 years ago). This encodes target insecticides, acetylcholinesterase. The described...

One view of adaptation is that it proceeds by the slow and steady accumulation beneficial mutations with small effects. It difficult to test this model, since in most cases genetic basis can only be studied a posteriori traits have evolved for long period time through an unknown sequence steps. In paper, we show how ace-1, gene involved resistance organophosphorous insecticide mosquito Culex pipiens, has during 40 years control program. Initially, major allele strong deleterious side effects...

Wolbachia symbionts are responsible for various alterations in host reproduction. The effects of the genome on endosymbiont levels have often been suggested, but rarely described. Here, we show that density is strongly modified by presence insecticide–resistant genes common house mosquito, Culex pipiens. was estimated using a real–time quantitative PCR assay. Strains harbouring different conferring resistance were more infected than susceptible strain with same genetic background. We this...

The role of inter-specific hybridisation is particular importance in mosquito disease vectors for predicting the evolution insecticide resistance. Two molecular forms Anopheles gambiae s.s., currently recognized as S and M taxa, are considered to be incipient sibling species. Hybrid scarcity field was suggested that differentiation taxa maintained by limited or absent gene flow. However, recent studies have revealed shared polymorphisms within forms, a better understanding occurrence flow...

It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is encoded by ace-1 gene, distinct and divergent from ace-2 which performs this function Drosophila . This an unprecedented situation within Diptera order because both ace genes derive old duplication are present most insects arthropods. Nevertheless, possesses only gene. Thus, a secondary loss occurred during evolution of Diptera, implying vital switch one gene ( ) to other ). We sampled 78 species,...

Retroelements represent a considerable fraction of many eukaryotic genomes and are considered major drives for adaptive genetic innovations. Recent discoveries showed that despite not normally using DNA intermediates like retroviruses do, Mononegaviruses (i.e., viruses with nonsegmented, negative-sense RNA genomes) can integrate gene fragments into the their hosts. This was shown Bornaviridae Filoviridae, sequences which have been found integrated germ line cells vertebrate Here, we show...

Current views about the impact of Wolbachia on Plasmodium infections are almost entirely based data regarding artificially transfected mosquitoes. This work has shown that reduces intensity in mosquitoes, raising exciting possibility using to control or limit spread malaria. Whether natural have same parasite-inhibiting properties is not yet clear. Wolbachia-mosquito combinations with a long evolutionary history are, however, key for understanding what may happen Wolbachia-transfected...

Abstract Widespread resistance to pyrethroids threatens malaria control in Africa. Consequently, several countries switched carbamates and organophophates insecticides for indoor residual spraying. However, a mutation the ace-1 gene conferring these compounds ( R allele), is already present. Furthermore, duplicated allele D ) recently appeared; characterizing its selective advantage mandatory evaluate threat. Our data revealed that unique duplication event, pairing susceptible resistant copy...

Gene copy-number variations are widespread in natural populations, but investigating their phenotypic consequences requires contemporary duplications under selection. Such have been found at the ace-1 locus (encoding organophosphate and carbamate insecticides' target) mosquito Anopheles gambiae (the major malaria vector); recent studies revealed intriguing complexity, consistent with involvement of various numbers types (susceptible or resistant to insecticide) copies. We used an integrative...

Abstract Wolbachia are maternally inherited endosymbiotic bacteria that infect many arthropod species and may induce cytoplasmic incompatibility (CI), resulting in abortive embryonic development. One host, Culex pipiens complex mosquitoes, displays high levels of variability both CI crossing types (cytotypes) DNA markers. We report here an analysis 14 mosquito strains, containing 13 variants, with different cytotypes. Cytotypes were ‐dependent, as antibiotic treatment rendered all strains...

ABSTRACT Wolbachia strains are maternally inherited endosymbiotic bacteria that infect many arthropod species and have evolved several different ways of manipulating their hosts, the most frequent way being cytoplasmic incompatibility (CI). CI leads to embryo death in crosses between infected males uninfected females as well individuals by incompatible strains. The mosquito Culex pipiens exhibits highest crossing type variability reported so far. Our data support notion might be driven at...

The γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus like organisms, ALOs) are emerging as a novel clade of endosymbionts, which exceptionally widespread in insects. biology ALOs is, however, most cases entirely unknown, it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination presence, diversity evolutionary history 25 related species blood-feeding flies: tsetse flies (Glossinidae), louse...

Resistance to insecticides has become a critical issue in pest management and it is particularly chronic the control of human disease vectors. The gravity this situation being exacerbated since there not been new insecticide class produced for over twenty years. Reasoned strategies have developed limit resistance spread but proven difficult implement field. Here we propose conceptual strategy based on inhibitors that preferentially target mosquitoes already resistant currently used...

Insecticide resistance owing to insensitive acetylcholinesterase (AChE)1 has been reported in several mosquito species, and only two mutations the ace-1 gene have implicated resistance: 119S 331W substitutions. We analyzed AChE1 status of Culex vishnui (Theobald) tritaeniorhynchus Giles sampled various regions China. These species displayed distinct leading insensitivity; substitution resistant C. mosquitoes tritaeniorhynchus. A biochemical test was validated detect mutation field samples....

Abstract Screening of the Anopheles funestus genomic DNA library detected 18 new sequences with dinucleotide tandem repeats. Primers were designed to amplify loci and 14 out gave a repeatable scorable amplification. Deviations from Hardy–Weinberg expectations tested for each locus in sample 30 wild females. No heterozygote deficiency was 11 14, thus revealing absence null alleles. The number alleles per ranged 5 15, observed heterozygosity 0.13 0.85.