Cues that guide gravid Anopheles gambiae sensu lato to oviposition sites can be manipulated to create new strategies for monitoring and controlling malaria vectors. However, progress towards identifying such cues is slow in part due to the lack of appropriate tools for investigating long-range attraction to putative oviposition substrates. This study aimed to develop a relatively easy-to-use bioassay system that can effectively analyse chemical attraction of gravid Anopheles gambiae sensu stricto. BG-Sentinel™ mosquito traps that use fans to dispense odourants were modified to contain aqueous substrates. Choice tests with two identical traps set in an 80 m2 screened semi-field system were used to analyse the catch efficacy of the traps and the effectiveness of the bioassay. A different batch of 200 gravid An. gambiae s.s. was released on every experimental night. Choices tested were (1) distilled versus distilled water (baseline) and (2) distilled water versus soil infusion. Further, comparisons were
1. Takken W, Knols BG. Odor-mediated behavior of Afrotropical malaria mosquitoes. Annu Rev Entomol. 1999;44:131-157 2. Zwiebel LJ, Takken W. Olfactory regulation of mosquito-host interactions. Insect Biochem Mol Biol. 2004;34:645-652 3. Himeidan YE, Temu EA, El rayah EA. et al. Chemical cues for malaria vectors oviposition site selection: Challenges and opportunities. Journal of Insects. 2013 Article ID685182: 1-9 4. Meijerink J, Braks MA, van Loon JJ. Olfactory receptors on the antennae of the malaria mosquito Anopheles gambiae are sensitive to ammonia and other sweat-borne components. J Insect Physiol. 2001;47:455-464 5. Lu T, Qiu YT, Wang G. et al. Odor coding in the maxillary palp of the malaria vector mosquito Anopheles gambiae. Curr Biol. 2007;17:1533-1544 6. Qiu YT, van Loon JJ, Takken W. et al. Olfactory coding in antennal neurons of the malaria mosquito, Anopheles gambiae. Chem Senses. 2006;31:845-863 7. McIver SB. Sensilla of mosquitoes (Diptera: Culicidae). J Med Entomol. ...
Synthetic versions of human derived kairomones can be used as baits when trapping host seeking mosquitoes. The effectiveness of these lures depends not only on their attractiveness to the mosquitoes but also on the medium from which they are dispensed.We report on the development and evaluation of nylon strips as a method of dispensing odorants attractive to the malaria vector, Anopheles gambiaes.s. (Giles).When a synthetic blend of attractants was dispensed using this method, signiÞcantly more mosquitoes were trapped than when two previous methods, open glass vials or low density polyethylene sachets were used. We conclude that the nylon strips are suitable for dispensing odorants in mosquito trapping operations and can be adopted for use in rural and remote areas. The nylon material required is cheap and widely available and the strips can be prepared without specialized equipment or ...
Anopheles gambiae sensu stricto, one of the principal vectors of malaria, has been divided into two subspecific groups, known as the M and S molecular forms. Recent studies suggest that the M form found in Cameroon is genetically distinct from the M form found in Mali and elsewhere in West Africa, suggesting further subdivision within that form. Chromosomal, microsatellite and geographic/ecological evidence are synthesized to identify sources of genetic polymorphism among chromosomal and molecular forms of the malaria vector Anopheles gambiae s.s. Cytogenetically the Forest M form is characterized as carrying the standard chromosome arrangement for six major chromosomal inversions, namely 2La, 2Rj, 2Rb, 2Rc, 2Rd, and 2Ru. Bayesian clustering analysis based on molecular form and chromosome inversion polymorphisms as well as microsatellites describe the Forest M form as a distinct population relative to the West African M form (Mopti-M form) and the S form. The Forest-M form was the most highly diverged
The long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are major malaria vector control strategies in Mali. The success of control strategies depends on a better understanding of the status of malaria vectors with respect to the insecticides used. In this study we evaluate the level of resistance of Anopheles gambiae (sensu lato) to bendiocarb and the molecular mechanism that underlies it. Larvae of An. gambiae (s.l.) were collected from breeding habitats encountered in the three study sites and bioassayed with bendiocarb. The ace-1 target site substitution G119S was genotyped using a TaqMan assay. The three species of the An. gambiae complex in Mali, i.e. An. arabiensis, An. coluzzii and An. gambiae (s.s.) were found in sympatry in the three surveyed localities with different frequencies. We observed a resistance and suspicious resistance of the three species to bendiocarb with a mortality rate ranging from 37% to 86%. The allelic frequency of the G119S mutation
Malaria is a serious threat to human life in sub-Saharan Africa, claiming many lives and causing the greatest morbidity as compared to other infectious diseases. Female Anopheles gambiae mosquito acts as the definitive host of Plasmodium protozoa, and allows sexual reproduction to take place in its gut. Infection rates may vary seasonally due to temperature changes, but this occurrence is not well studied in the Kenyan highlands. This study therefore aimed at investigating the seasonal variations in infection of Anopheles gambiae by Plasmodium oocysts and its implications on malaria prevalence in human beings. The study was conducted in three estates namely, Daraja mbili, Mwembe, and Maili Mbili which surround Kisii town in Nyanza province. Three villages in Keumbu location which is in the outskirts of Kisii town were also sampled to represent the rural population. Bi-weekly collection of mosquitoes during both wet and dry seasons was done for a period of 2 months in each season. Data were ...
Background: The non-random distribution of anopheline larvae in natural habitats suggests that gravid females discriminate between habitats of different quality. Whilst physical and chemical cues used by Culex and Aedes vector mosquitoes for selecting an oviposition site have been extensively studied, those for Anopheles remain poorly explored. Here the habitat selection by Anopheles gambiae sensu lato (s.l.), the principal African malaria vector, was investigated when presented with a choice of two infusions made from rabbit food pellets, or soil. Methods: Natural colonization and larval survival was evaluated in artificial ponds filled randomly with either infusion. Dual-choice, egg-count bioassays evaluated the responses of caged gravid females to (1) two- to six-day old infusions versus lake water; (2) autoclaved versus non-autoclaved soil infusions; and assessed (3) the olfactory memory of gravid females conditioned in pellet infusion as larvae. Results: Wild Anopheles exclusively colonized ...
Kabbale, F., Akol, A., Kaddu, J., & Onapa, A. (2013). Biting patterns and seasonality of Anopheles gambiae sensu lato and Anopheles funestus mosquirtoes in Kamuli District, Uganda. Parasites and Vectors, 12, 1 - 20 ...
The work included in this thesis arose from a long-standing interest in the possible use of genetic control for one of the most important malaria vectors in Africa, Anopheles gambiae sensu stricto. It was hoped that the genes involved in animal biting in the sibling species Anopheles quadriannulatus could be exploited by crossing with An. gambiae s. s. and using the fertile female hybrids for successive backcrosses to An. gambiae s. s.. It was envisaged that this method could be used in an attempt to produce a mosquito stock that is harmless to humans because it is zoophilic but with the genetic background of An. gambiae s. s. so that there would be no barriers to cross-mating in the wild. The innate host preference of mosquitoes can be determined in the laboratory using an olfactometer, or in the field using baits. Host-selection patterns in nature are often affected by external factors, which may or may not mask the host preference of the mosquito species in question (discussed in section ...
Anopheles gambiae AGER protein: AGER - EGFR ortholog from Anopheles; from the malaria mosquito Anopheles gambiae: orthologs from Drosophila, human, mouse & chicken; Genbank, AJ301655 and AJ304406
... for FGENESH the program with parameters for major model organisms is available for on line usage at: http://www.softberry.com/berry.phtml?topic=gfind Method description: A new parameter set for gene prediction Anopheles gambiae is developed for FGENESH program. Accuracy of prediction of Plasmodium falciparum protein coding genes is about 98% on the nucleotide level. The FGENESH algorithm is based on pattern recognition of different types of signals and Markov chain models of coding regions. Optimal combination of these features is then found by dynamic programming and a set of gene models is constructed along given sequence. FGENESH is the fastest and most accurate ab initio gene prediction program available. Fgenesh output: fgenesh Tue Nov 5 16:23:15 EST 2002 FGENESH 1.1 Prediction of potential genes in Anopheles_gambiae genomic DNA Time : Tue Nov 5 16:23:16 2002 Seq name: Softberry SERVER PAST Sequence Length of sequence: 1542 Number of predicted genes ...
Various strategies that block malaria transmission from an infected human host to a female Anopheline mosquito that involve killing of the blood fed mosquito have been studied as a potential strategy to control malaria. These include the immunization of animal hosts with either whole homogenized blood fed mosquito midguts or their extracts. In 1939, William Trager first demonstrated anti-vector immunity by immunizing guinea pigs and rabbits with extracts of the tick Dermacentor variabilis. This immunological targeting of tick midgut antigens led to the commercial development of a vaccine against Boophilus microplus ticks licenced in 1985.This study investigated the mosquitocidal effects of an immune response elicited by immunization of BALB/c mice with a gene, Anopheles gambiae mucin 1 gene (AgMUC1 gene) alone or in combination with immunostimulatory cytokine genes GM-CSF or IL-12. The AgMUC1 genes were cloned from the midgut of blood fed female Anopheles gambiae mosquitoes. Four groups of ...
Anopheles gambiae sensu lato (s.l.) consists of several morphologically cryptic species throughout sub-Saharan Africa. In the Sahel region of Mali, this complex includes Anopheles arabiensis (Patton 1905) and A. gambiae sensu stricto (s.s.) (Giles 1902), which is further divided into the M and S molecular forms; all are important malaria vectors (Coluzzi et al., 1979; Collins et al., 2001; della Torre et al., 2001; Coluzzi et al., 2002; della Torre et al., 2002). Although they are morphologically indistinguishable and can occur in sympatry (Lindsay et al., 1998; Coluzzi et al., 2002; della Torre et al., 2002; della Torre et al., 2005; Simard et al., 2009), these cryptic species often differ in abundance according to season, local rainfall, latitude and larval site characteristics (Gimnig et al., 2001; Edillo et al., 2002; Koenraadt et al., 2004; Diabaté et al., 2005; Edillo et al., 2006; Diabaté et al., 2008; Costantini et al., 2009), and thus local differentiation may occur between these ...
Anopheles gambiae sensu stricto was recently reclassified as two species, An. coluzzii and An. gambiae s.s., in wild-caught mosquitoes, on the basis of the molecular form, denoted M or S, of a marker on the X chromosome. The An. gambiae Keele line is an outbred laboratory colony strain that was developed around 12 years ago by crosses between mosquitoes from 4 existing An. gambiae colonies. Laboratory colonies of mosquitoes often have limited genetic diversity because of small starting populations (founder effect) and subsequent fluctuations in colony size. Here we describe the characterisation of the chromosomal form(s) present in the Keele line, and investigate the diversity present in the colony using microsatellite markers on chromosome 3. We also characterise the large 2La inversion on chromosome 2. The results indicate that only the M-form of the chromosome X marker is present in the Keele colony, which was unexpected given that 3 of the 4 parent colonies were probably S-form. Levels of diversity
BACKGROUND: The strategy for malaria vector control in the context of reducing malaria morbidity and mortality has been the scale-up of long-lasting insecticidal nets to universal coverage and indoor residual spraying. This has led to significant decline in malaria transmission. However, these vector control strategies rely on insecticides which are threatened by insecticide resistance. In this study the status of pyrethroid resistance in malaria vectors and its implication in malaria transmission at the Kenyan Coast was investigated. RESULTS: Using World Health Organization diagnostic bioassay, levels of phenotypic resistance to permethrin and deltamethrin was determined. Anopheles arabiensis showed high resistance to pyrethroids while Anopheles gambiae sensu stricto (s.s.) and Anopheles funestus showed low resistance and susceptibility, respectively. Anopheles gambiae sensu lato (s.l.) mosquitoes were further genotyped for L1014S and L1014F kdr mutation by real time PCR. An allele frequency ...
Anopheles gambiae sensu lato IS a major vector of malaria in western Kenya where environmental conditions are highly conducive for its survival and reproduction. Breeding mostly occurs in newly formed small and transient water bodies but as the habitats age they may become unattractive for breeding of the species. The aim of this study was to deduce some of the ecological implications of this strategy of early colonization of breeding sites by Anopheles gambiae s.l. Ten semi-natural habitats (5 small and 5 large) were studied longitudinally (sampled same population over time) for a period of 12 weeks with daily sampling of all larval and pupal stages and quantification of all other identifiable aquatic fauna. This was followed by a final census and retrieval of all inhabitants of each habitat. A new set of 10 habitats was investigated together with the old habitats using the same procedures for an additional period of 9 weeks. Larval cohorts lasting on average twelve days were easily noticeable ...
Smelly feet and heat - how malaria mosquitoes find their hosts. Spitzen et al. [1], studied the host-seeking behavior of the malaria mosquito Anopheles gambiae sensu stricto.
When natural larval habitats of An. gambiae s.l. dry up, their contribution towards the population dynamics of the adult stage is often neglected, since mass larval mortality is assumed to occur [9]. We found that eggs of An. gambiae s.s. hatched and that emerging larvae showed limited capability of reaching a nearby breeding site, when placed on damp soil. With this experiment we simulated a natural situation whereby eggs remain on damp soil when the water level drops or eggs are oviposited deliberately on damp soil after desiccation of the habitat [8, 10]. In addition, we found that larvae of An. gambiae s.s. survive for several days in sites that are drying up, depending on the larval stage.. Larvae that hatch from eggs on damp soil were able to reach a breeding site within a distance of 10 cm, albeit in low numbers. We induced hatching of the eggs by keeping the soil of our experimental sites damp by daily spraying of water, but during spraying we made sure that no water ran off or that a ...
Author Summary Malaria causes more than one million deaths every year, mostly among children in Sub-Saharan Africa. Anopheles mosquitoes are exclusive vectors of human malaria. Many malaria vectors belong to species complexes, and members within these complexes can vary significantly in their ecological adaptations and ability to transmit the parasite. To better understand evolution of epidemiologically important traits, we studied relationships among nonvector and vector species of the African Anopheles gambiae complex. We analyzed gene orders at genomic regions where evolutionary breaks of chromosomal inversions occurred in members of the complex and compared them with gene orders in species outside the complex. This approach allowed us to identify ancient and recent gene orders for three chromosomal inversions. Surprisingly, the more ancestral chromosomal arrangements were found in mosquito species that are vectors of human malaria, while the more derived arrangements were found in both nonvectors
To help improve the functional annotation of the Anopheles gambiae genome we have generated the MozAtlas, a unified catalogue of tissue-specific gene expression from a single mosquito strain. In Drosophila melanogaster, cataloguing tissue expression patterns has been useful, especially for inferring biological functions, since the majority of genes encoded in the genome are not ubiquitously expressed [19]. As with the fruit fly, Anopheles gene expression also exhibits substantial tissue specificity, with only a third of detectably expressed genes found in all tissues. Thus, the MozAtlas is a useful resource for better understanding the mosquito genome, providing direct evidence of genes with tissue restricted expression. Below we highlight the utility of MozAtlas for identifying classes of gene with tissue or sex-biased expression that may be exploited for vector control. Analysis of the MozAtlas also identifies gene expression features that are of interest from an evolutionary perspective, ...
Serine proteases play a crucial role during the digestion of the blood meal in the mosquito gut. The isolation and the analysis of the genomic organisation of the corresponding genes may lead to the characterization of gut-specific, inducible promoters, suitable for the expression of anti-parasitic agents in the gut of transgenic mosquitoes. We report here on the identification of a trypsin and a chymotrypsin gene family of Anopheles gambiae. Following a blood meal, the transcription of all members of the two identified gene clusters, seven trypsin genes (Antryp1-7) and two chymotrypsin genes (Anchym1-2), is induced. Recombinant Antryp1 and Antryp2, expressed in E. coli, were both active in vitro against blood proteins. Moreover, mouse sera raised against Antryp1, Anchym1 and Anchym2 recognized the corresponding proteases among the proteins of a lysate prepared from dissected guts of An. gambiae mosquitoes.. ...
Sawadogo, Simon P., Costantini, Carlo, Pennetier, Cédric, Diabaté, Abdoulaye, Gibson, Gabriella and Dabiré, Roch K. (2013) Differences in timing of mating swarms in sympatric populations of Anopheles coluzzii and Anopheles gambiae s.s. (formerly An. gambiae M and S molecular forms) in Burkina Faso, West Africa. Parasites & Vectors, 6 (1):275. ISSN 1756-3305 (Print), 1756-3305 (Online) (doi:10.1186/1756-3305-6-275) Pennetier, Cédric, Warren, Ben, Dabiré, K. Roch, Russell, Ian J. and Gibson, Gabriella (2009) "Singing on the wing" as a mechanism for species recognition in the malarial mosquito Anopheles gambiae. Current Biology, 20 (2). pp. 131-136. ISSN 0960-9822 (doi:10.1016/j.cub.2009.11.040) Bonnet, Julien, Pennetier, Cédric, Duchon, Stéphane, Lapied, Bruno and Corbel, Vincent (2009) Multi-function oxidases are responsible for the synergistic interactions occurring between repellents and insecticides in mosquitoes. Parasites & Vectors, 2 (17). ISSN 1756-3305 (doi:10.1186/1756-3305-2-17) ...
Here we present data on a cluster of 3 female LRT-specific serine protease genes suggested to be involved in post-mating processes in A. gambiae s.s. As already shown for other genes with different functions, the reconstruction of the 3 gene-trees shows that most species share alleles at all loci, as an effect of introgression and/or retention of ancestral polymorphisms, and that only A. merus and A. melas are placed in monophyletic assemblages (Figure 2). On the other hand, we found an unusually high substitution rate, which contributes mostly to an exceptionally high level of intra-specific polymorphisms, especially at nonsynonymous sites (Table 1). Moreover, while A. gambiae, A. arabiensis, and A. quadriannulatus do not differ for any fixed replacement, A. melas and A. merus diverge from the other species at all loci, showing a high number of fixed substitutions at both synonymous (7-9) and nonsynonymous (13-23) sites at locus AGAP005195.. The comparisons of different site-models - used to ...
The Genetics Society of America (GSA), founded in 1931, is the professional membership organization for scientific researchers and educators in the field of genetics. Our members work to advance knowledge in the basic mechanisms of inheritance, from the molecular to the population level.. Online ISSN: 1943-2631. ...
Mosquitoes are important vectors of infectious diseases and successful transmission depends on the efficacy of host discrimination and blood uptake. This process is directed by the need for the mosquito to feed on those hosts that provide greatest fitness. We have preliminary evidence that mosquitoes can detect the quality of the blood meal based on the volatiles emitted from the human skin. The mosquito would thus be able to decide who is the best host for the development of her eggs. We will unravel one of the most important evolutionary mechanisms behind mosquito host choice by answering the hypothesis that malaria mosquitoes detect the quality of a host by its skin volatiles. Therefore, we will link someones attractiveness towards mosquitoes with his/her blood quality. Blood of 40 individuals will be analysed and fed to the malaria mosquito Anopheles gambiae in vivo and in vitro to determine differences in egg production. In addition, odour samples will be analysed and tested for ...
Renal function is essential to maintain homeostasis. This is particularly significant for insects that undergo complete metamorphosis; larval mosquitoes must survive a freshwater habitat whereas adults are terrestrial, and mature females must maintain ion and fluid homeostasis after blood feeding. To investigate the physiological adaptations required for successful development to adulthood, we studied the Malpighian tubule transcriptome of Anopheles gambiae using Affymetrix arrays. We assessed transcription under several conditions; as third instar larvae, as adult males fed on sugar, as adult females fed on sugar, and adult females after a blood meal. In addition to providing the most detailed transcriptomic data to date on the Anopheles Malpighian tubules, the data provide unique information on the renal adaptations required for the switch from freshwater to terrestrial habitats, on gender differences, and on the contrast between nectar-feeding and haematophagy. We found clear differences ...
Both new and previously identified immune markers are expressed in adult mosquitoes, and thus are suited for monitoring induction by the malaria parasite. The markers show distinct and in some cases complex developmental expression profiles, which may reflect potential non‐defence‐related functions. Developmental and immune‐related processes often share the same components: examples are regulatory factors such as Dif, Dorsal and Relish in D.melanogaster (Dushay et al., 1996; Hoffmann et al., 1996), or effectors such as the Sarcophaga antibacterial defence proteins sapecin, sapecin B and cathepsin L (Natori and Kubo, 1996). Some of the A.gambiae infection‐responsive markers, GNBP, IGALE20 and ICHIT, encode adhesive motifs (Dimopoulos et al., 1996, 1997), and could be involved both in binding to microbial substances in defence and in the removal of apoptotic cells and tissue remodelling during development. NOS is known to have multiple functions in a variety of physiological processes. The ...
integral component of membrane, mitochondrial inner membrane, L-aspartate transmembrane transporter activity, L-glutamate transmembrane transporter activity, aspartate transport, L-glutamate transmembrane transport, malate-aspartate shuttle
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
2015) Efficacy, Persistence and Vector Susceptibility to Pirimiphos-methyl (Actellic® 300CS) Insecticide for Indoor Residual Spraying in Zanzibar. Parasites & vectors, 8 (1). p. 628. ISSN 1756-3305 (2014) Islands and Stepping-Stones: Comparative Population Structure of Anopheles gambiae sensu stricto and Anopheles arabiensis in Tanzania and Implications for the Spread of Insecticide Resistance. PloS one, 9 (10). e110910. ISSN 1932-6203 (2013) Challenges for Malaria Elimination in Zanzibar: Pyrethroid Resistance in Malaria Vectors and Poor Performance of Long-Lasting Insecticide Nets. Parasites & vectors, 6 (1). p. 82. ISSN 1756-3305 (2013) The Dynamics of Pyrethroid Nesistance in Anopheles Arabiensis from Zanzibar and an Assessment of the Underlying Genetic Basis. Parasites & vectors, 6. p. 343. ISSN 1756-3305 ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Malaria is a blood-borne human disease, and is transmitted to mosquitoes in the bloodmeal, an obligatory step in human malaria transmission. This is a study of malaria parasites in the major mosquito vector of human malaria in Africa, Anopheles gambiae. The intent of the study is to develop modern forms of vector control that would specifically decrease disease transmission by targeting the vector. Genetic linkage mapping of the mosquito vector (Anopheles gambiae) in Africa has identified a small genomic region in the mosquito that controls most of the natural genetic variation for resistance to mosquito infection with the human malaria parasite (Plasmodium falciparum). In order to study the influence of mosquito vector genetics on transmission of malaria parasites, mosquitoes are exposed to malaria parasites and then the efficiency of parasite development within the mosquito is measured. The goal of the study is to promote and expand this non-transmitting subset of the vector population in ...
Malaria is a blood-borne human disease, and is transmitted to mosquitoes in the bloodmeal, an obligatory step in human malaria transmission. This is a study of malaria parasites in the major mosquito vector of human malaria in Africa, Anopheles gambiae. The intent of the study is to develop modern forms of vector control that would specifically decrease disease transmission by targeting the vector. Genetic linkage mapping of the mosquito vector (Anopheles gambiae) in Africa has identified a small genomic region in the mosquito that controls most of the natural genetic variation for resistance to mosquito infection with the human malaria parasite (Plasmodium falciparum). In order to study the influence of mosquito vector genetics on transmission of malaria parasites, mosquitoes are exposed to malaria parasites and then the efficiency of parasite development within the mosquito is measured. The goal of the study is to promote and expand this non-transmitting subset of the vector population in ...
The original description of clathrin-coated vesicles as intracellular transport shuttles was based upon ultrastructural studies of developing mosquito oocytes (Roth and Porter, 1964). Vesicular profiles encased within a `bristle coat were very prominent at the cortex of Aedes aegypti oocytes several hours following a blood meal (Roth and Porter, 1964). The dramatic appearance of this bristle border, which we now know is composed of clathrin and associated coat proteins, reflects the fact that both A. aegypti and Anopheles gambiae mosquitoes are anautogenous - adult females must feed before egg production (Raikhel and Dhadialla, 1992). Thus, unlike Drosophila melanogaster, where a succession of progressively more mature egg chambers develop continuously (Drummond-Barbosa and Spradling, 2001; Schonbaum et al., 2000), egg maturation in newly eclosed A. aegypti or A. gambiae females developmentally arrests at a previtellogenic stage (Raikhel and Dhadialla, 1992; Roth and Porter, 1964). A blood meal ...
The ability to detect chemical information from the environment is of critical importance to insects, whose ecological and evolutionary boundaries typically revolve around taste and smell. Of the receptors involved in chemoperception, the gustatory receptor (Gr) protein family comprises most of the diversity in the insect chemoreceptor superfamily, including within it not only taste receptors, but select olfactory receptors as well. Manual annotation of the Gr family in the genome sequence of the yellow fever mosquito, Aedes aegypti Linnaeus, yielded a total of 114 potential proteins encoded by 79 genes. In the sequenced genome, 23 of these genes and protein isoforms are pseudogenic, leaving 91 putatively functional Grs. Comparison with the set of 76 Grs encoded by 52 genes in the distantly related Anopheles gambiae Giles mosquito revealed 13 new AgGrs encoded by eight genes. Phylogenetic analysis reveals the conservation of carbon dioxide, sugar and several orphan receptors in these two ...
Malaria is vectored by the mosquito Anopheles gambiae (Ag) in Sub-Saharan Africa and infects approximately 500 million people annually. The increasing prevalence of pyrethroid-resistant mosquitoes has amplified the need for development of new, selective mosquitocides for use on insecticide-treated nets. We have developed several phenyl-substituted N-methylcarbamates producing a high degree of selectivity for Anopheles gambiae acetylcholinesterase (AgAChE) over human AChE. Molecular models suggest alternate conformations (flexibility) of W84 and W431 (Ag numbering) at the hydrophobic subpocket of the AgAChE active site and poor flexibility within human AChE, allowing for the high selectivity of our novel carbamates. Initial selectivity data was obtained through screening of these insecticides while using ethanol as a solvent. Re-screening of these carbamates in the presence of 0.1% DMSO (v/v) resulted in antagonism of inhibition for AgAChE, thus reducing the AgAChE-selectivity by at least ...
The pyrethroid knockdown resistance gene (kdr) has become widespread in Anopheles gambiae in West Africa. A trial to test the continuing efficacy of insecticide-treated nets (ITN) and indoor residual spraying (IRS) was undertaken in experimental huts at 2 sites in Benin, the first where kdr is present at high frequency (Ladji), the second-where An. gambiae is susceptible (Malanville). Holes were made in the nets to mimic worn nets. At Malanville, 96% of susceptible An. gambiae were inhibited from blood-feeding, whereas at Ladji feeding was uninhibited by ITNs. The mortality rate of An. gambiae in ITN huts was 98% in Malanville but only 30% at Ladji. The efficacy of IRS was equally compromised. Mosquitoes at Ladji had higher oxidase and esterase activity than in a laboratory-susceptible strain, but this fact did not seem to contribute to resistance. Pyrethroid resistance in An. gambiae appears to threaten the future of ITN and IRS in Benin ...
Vector control is a major component of the malaria control strategy. The increasing spread of insecticide resistance has encouraged the development of new tools such as genetic control which use releases of modified male mosquitoes. The use of male mosquitoes as part of a control strategy requires an improved understanding of male mosquito biology, including the factors influencing their survival and dispersal, as well as the ability to accurately estimate the size of a target mosquito population. This study was designed to determine the seasonal variation in population size via repeated mark-release-recapture experiments and to estimate the survival and dispersal of male mosquitoes of the Anopheles gambiae complex in a small west African village ...
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UC Riversides Bradley White has received a five-year grant of more than $1.8 million from the National Institute of Allergy and Infectious Diseases to
Researchers at the Johns Hopkins Malaria Research Institute demonstrated for the first time that the Anopheles mosquitos innate immune system could be genetically engineered to block the...
In an article published in Nature Communications in January of 2015, a connection was revealed between the presence of antibiotics in human blood and increased mosquito transmissibility of malaria. The apparent link, between the otherwise disparate concepts, lies in the effect of antibiotics on the gut flora of the Anopheles gambiae mosquito - the main vector involved in malaria transmission [1]. It is largely accepted that the use of antibiotics in humans can change the personal microbiome, including the makeup of gut flora. However, it has also been argued that these changes may be permanent [2]. Long-term antibiotic use has been shown to increase susceptibility to infections, such as Clostridium difficile [3], by way of changes or reductions in the good bacteria in our gut flora. The effects of antibiotics on human microbiomes has been significantly studied and considered. What has not been considered are the effects of human antibiotic use on disease vectors. The Nature Communications study ...
Scientists at the University of Notre Dame have found that exposure to just 10 minutes of light at night suppresses biting and manipulates flight behavior in the Anopheles gambiae mosquito, the major vector for transmission ...
Originally From: Kostas Iatrou ,iatrou at bio.demokritos.gr, NATIONAL CENTRE FOR SCIENTIFIC RESEARCH DEMOKRITOS INSTITUTE OF BIOLOGY Insect Molecular Genetics and Biotechnology Group Director: Prof. Kostas Iatrou, PhD Tel: 210 650 3562, Email: iatrou at bio.demokritos.gr POST-DOCTORAL POSITION FOR STUDIES ON MOSQUITO OLFACTION A post-doctoral position to study the molecular and functional properties of odorant receptors in the malaria mosquito vector Anopheles gambiae is available in the laboratory of Insect Molecular Genetics and Biotechnology , Institute of Biology, National Centre for Scientific Research Demokritos . The research is conducted under the framework of a 4-year European research project entitled ENAROMaTIC: European Network for Advanced Research on Olfaction for Malaria Transmitting Insect Control . The project aims at a reduction in the frequency of malaria transmission through interference with the mosquito s capacity to detect in its environment the presence of odors of human ...
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Phylogenetic analysis of PLC-γ proteins: The PLC-γ homolog encoded by sl is the only one present in the now almost-complete D. melanogaster genome sequence, and only a single gene has been identified in the other invertebrate genomes sequenced to date. By contrast, a gene duplication event produced separate γ1 and γ2 subtypes at some point in the vertebrate lineage; each subtype has identical domain structure and similar sequence, but distinct functions. To reveal the relationships between PLC-γ homologs, we produced a translation of the putative ORFs from both D. pseudoobscura and D. virilis and compared them to all other complete PLC-γ homologs in the GenBank database, including D. melanogaster, the mosquito Anopheles gambiae, the sponge E. fluviatilis, the nematode Caenorhabditis elegans, the cow Bos taurus (γ1), the rat Rattus rattus (γ1 and γ2), and Homo sapiens (γ1 and γ2). The best tree from this comparison is shown in Figure 1A. The tree divides the taxa unambiguously into a ...
F5HL56 , AGAP004222-PB (Anopheles gambiae) from UniProtKB/TrEMBL Length: 534 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 520 530 F5HL56_ANOGA 1 MDTLIGSLLVDDIGVARQRQQVRIAEQSHTVWSAGIVTERSGFDQQIPSTTSSTILATVVGGSATVGLEPGSSIPTPFAVLLAHNQTTGDHGFGHGFTGDGGDAGGSGSGEAIVGPAASIGIGGSLGVPLAGGTTVATIVSSTLANATLSEHELDLDTIRKVIICIVLLAVIFGTIVGNILVCVAVCLVRKLRRPCNYLLVSLAVSDLCVACLVMPPALMYEVLGEWNFGRVFCDIWVSFDVLSCTASILNLCAISVDRYWAITKPLEYGVKRTPRRMMLCVALVWLAAACISLPPLLILGNKHTIGEGPDQRPFCAVCEDVGYQIYATLGSFYIPLAVMLFVYYQIFRAARRIVKDEKRAQTRLENSLAVDKTSTTAATTTTTTTSMSLKPPDSIVPAMSVGGGSPHQKKLRFQLAKERKASTTLGIIMSAFTICWLPFFILALVRPLMDDDYPTLSSFFLWLGYANSLLNPIIYATLNRDFRKPFQEILYFRCSNLNILMREDFYHSQYGEPGSQRFVLENEGQHTARESFL 534 ...
This is a double‐blind, randomised, placebo‐controlled, parallel‐group, 3‐arm, dose‐finding trial in adults with uncomplicated malaria. Monte Carlo simulations based on pharmacokinetic modelling were performed to determine the optimum dosing regimens to be tested. Modelling showed that a 3‐day regimen of 600 mcg/kg/day achieves similar median (5‐95 percentiles) Cmax concentrations of ivermectin to single‐dose of 800 mcg/kg, while increasing the median time above the LC50 (16 ng/mL) from 1.9 days (1.0‐5.7) to 6.8 (3.8‐13.4) days. The 300 mcg/kg/day dose was chosen at 50% of the higher dose to allow evaluation of the dose response. Mosquito survival will be assessed daily up to 28 days in laboratory‐reared Anopheles gambiae s.s. populations fed on patients blood taken at days 0, 2 (Cmax), 7 (primary outcome), 10, 14, 21, and 28 after the start of treatment. Safety outcomes include QT‐prolongation and mydriasis. The trial will be conducted in 6 health facilities in western ...
This is a critical topic for developing genetic control of mosquito vectors since all genetic programs require mating between wild mosquitoes and some type of modified mosquito that will be released. Competitiveness among males for mating with wild virgin females is an - perhaps THE most - important characteristic, but little has been known about what characteristics promote male competitiveness.. Furthermore, how does con-specific mate recognition occur between closely related forms such as the An. gambiae M and S molecular forms.. These two forms are known to segregate based on genetic data, but the means was not clear: is recognition olfactory, swarm timing, location, auditory?. Insight has been provided by two studies particularly: one on a possible mechanism by which individuals recognize similar molecular forms and another regarding the locations of swarms in natural settings .. Pennetier et al. recently reported that wingbeat matching between M and S types occurred less frequently than ...
Gene expression is known to vary extensively among tissues and between sexes. However, detailed descriptions of tissue-and sex-specific gene expression are available for only a few model organisms. A new study published in BMC Genomics presents such a data set for the mosquito, Anopheles gambiae, which is the vector of human malaria. In addition to providing a valuable resource for the community of mosquito researchers, the study allows comparative transcriptomic studies of dipteran insects to be extended over 250 million years of evolution, since the divergence of A. gambiae and Drosophila melanogaster. ...