Diphenyl ether herbicides induce an accumulation of protoporphyrin IX in plant tissues. By analogy to human porphyria, the could be attributed decreased (Mg or Fe)-chelatase protoporphyrinogen oxidase activities. Possible effects acifluorfen-methyl on these enzymes were investigated isolated corn (maize, Zea mays) etioplasts, potato (Solanum tuberosum) and mouse mitochondria, yeast mitochondrial membranes. Acifluorfen-methyl was strongly inhibitory activities whatever their origins [concn....

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...

In the mosquito Culex pipiens, insecticide resistance genes alter many life‐history traits and incur a fitness cost. Resistance to organophosphate insecticides involves two loci, with each locus coding for different mechanism of (degradation vs. insensitivity insecticides). The density intracellular Wolbachia bacteria has been found be higher in resistant mosquitoes, regardless involved. To discriminate between costs due from those associated elevated densities, we compared strains sharing...

In the mosquito Culex pipiens, insecticide resistance genes alter many life-history traits and incur a fitness cost. Resistance to organophosphate insecticides involves two loci, with each locus coding for different mechanism of (degradation vs. insensitivity insecticides). The density intracellular Wolbachia bacteria has been found be higher in resistant mosquitoes, regardless involved. To discriminate between costs due from those associated elevated densities, we compared strains sharing...

Iron reduction and uptake was studied in wild-type haem-deficient strains of Saccharomyces cerevisiae. Haem-deficient lacked inducible ferri-reductase activity were unable to take up iron from different ferric chelates such as Fe(III)-citrate or rhodotorulic acid. In contrast, ferrioxamine B taken actively by the mutants well strains. At a low extracellular concentration, insensitive ferrozine competitively-inhibited Ga(III)-desferrioxamine B. Extracellular reductive dissociation siderophore...

Wolbachia bacteria have invaded many arthropod species by inducing Cytoplasmic Incompatibility (CI). These symbionts represent fascinating objects of study for evolutionary biologists, but also powerful potential biocontrol agents. Here, we assess the density dynamics infections in males and females mosquito Aedes albopitcus, an important vector human pathogens, interpret results within framework.Wolbachia densities were measured natural populations age controlled mosquitoes using...

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...

Dose-response relationships reflect the effects of a substance on organisms, and are widely used in broad research areas, from medicine physiology, to vector control pest management agronomy. Furthermore, reporting response organisms stressors is an essential component many public policies (e.g. health, environment), assessment xenobiotic responses integral part World Health Organization recommendations. Building upon R script that we previously made available, considering its popularity,...

Abstract Background Mosquitoes of the Culex pipiens complex are widely distributed vectors for several arboviruses affecting humans. Consequently, their populations have long been controlled using insecticides, in response to which different resistance mechanisms selected. Moreover, ecological preferences and broad adaptability allow C. mosquitoes breed highly polluted water bodies where they exposed many residuals from anthropogenic activities. It has observed mosquito species that...

Plant protoporphyrinogen oxidase is of particular interest since it the last enzyme common branch for chlorophyll and heme biosynthetic pathways. In addition, target diphenyl ether-type herbicides, such as acifluorfen. Two distinct methods were used to investigate localization this within Percoll-purified spinach chloroplasts. We first assayed enzymatic activity by spectrofluorimetry we analyzed specific binding herbicide acifluorfen, using highly purified chloroplast fractions. The results...

Ferrochelatase was purified to homogeneity from yeast mitochondrial membranes and found be a 40-kDa polypeptide with pI at 6.3. Fatty acids were absolutely necessary measure the activity in vitro. The Michaelis constants for protoporphyrin IX (9 x 10(-8) M), ferrous iron (1.6 10(-7) zinc 10(-6) M) determined on enzyme preparations presence of dithiothreitol. However, Km lower when measured absence dithiothreitol (K-m(Zn2+) = 2.5 M, Km(protoporphyrin) unchanged). maximum velocities 35,000...

Abstract Background Insecticide resistance is a rapid and recent evolutionary phenomenon with serious economic public health implications. In the mosquito Anopheles gambiae s.s ., main vector of malaria, to organophosphates carbamates mainly due single amino-acid substitution in acetylcholinesterase 1 (AChE1). This mutation entails large fitness cost. However, resistant duplicated allele gene encoding AChE1 ( ace-1 ), potentially associated lower cost, recently appeared An. . Methods Using...

Many insect species harbor Wolbachia bacteria that induce cytoplasmic incompatibility (CI), i.e. embryonic lethality in crosses between infected males and uninfected females, or females carrying incompatible strains. The molecular mechanism of CI remains unknown, but the available data are best interpreted under a modification–rescue model, where mod function disables reproductive success males' sperm, unless eggs express compatible resc function. Here we examine evolution mosquito Culex...

Background The control of Aedes albopictus, a major vector for viral diseases, such as dengue fever and chikungunya, has been largely reliant on the use larvicide temephos many decades. This insecticide remains primary tool several countries it is potential reliable reserve, emergency epidemics or new invasion cases, in regions Europe which have banned its use. Resistance to detected some regions, but mechanism responsible trait not investigated. Principal findings Temephos resistance was...

Gene duplications are widespread in genomes, but their role contemporary adaptation is not fully understood. Although mostly deleterious, homogeneous that associate identical repeats of a locus often increase the quantity protein produced, which can be selected certain environments. However, another type exists: heterogeneous gene duplications, permanently two (or more) alleles single on same chromosome. They far less studied, as only few examples known. Haldane proposed 1954 they could...

Wolbachia are endosymbiotic bacteria inducing various reproductive manipulations of which cytoplasmic incompatibility (CI) is the most common. CI leads to reduced embryo viability in crosses between males carrying and uninfected females or those an incompatible symbiont strain. In mosquito Culex pipiens , w Pip causes highly complex crossing patterns. This complexity linked amplification diversification causal genes, cidA cidB with polymorphism located CidA-CidB interaction regions. We...

Diphenyl ethers (DPEs) and related herbicides are powerful inhibitors of protoporphyrinogen oxidase, an enzyme involved in the biosynthesis haems chlorophylls. The inhibition kinetics oxidase various origins by four DPEs, (methyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen its methyl ester, acifluorfen-methyl), methyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-chlorobenzoate (LS 820340) methyl-5-[2-chloro-5-(trifluoromethyl)phenoxy]-2-nitrobenzoic (RH 5348),...

Adaptation occurs by gene replacement (or transient balanced polymorphism). Replacement may be caused selection (local or global) and/or genetic drift among alleles. In addition, historical events blur the respective effects of and during course replacement. We address relative importance these processes in evolution insecticide resistance genes mosquito Culex pipiens. The allele, Ester2, has a broad geographic distribution compared to other To distinguish between different explaining this...

Abstract How adaptation appears and is later refined by natural selection has been the object of intense theoretical work. However, testing these theories limited our ability to estimate strength in nature. Using a long-term cline series, we coefficients acting on different alleles at same locus analyze allele replacement observed insecticide resistance gene Ester mosquito Culex pipiens Montpellier area, southern France. Our method allows us accurately account for this area since 1986. A...

Wolbachia are maternally inherited endosymbiotic bacteria, widespread among arthropods thanks to host reproductive manipulations that increase their prevalence into populations. The most commonly observed manipulation is cytoplasmic incompatibility (CI). CI leads embryonic death in crosses between i) infected males and uninfected females ii) individuals with incompatible strains. can be conceptualized as a toxin-antidote system where toxin deposited by the sperm would induce unless countered...