Project description:Malaria is as one of the most debilitating mosquito-borne global health burdens. While much of the malaria and mosquito-borne disease attention have focused on Africa, South East Asia accounts for a sizable portion of the malaria global burden. Moreover, about 50% of the Asian malaria incidence and deaths have been from India. The completion of genome sequence of Anopheles stephensi, a major malaria vector in Asia, offers new opportunities for global health innovation, not to mention for progress in deciphering the vectorial ability of this mosquito species at a molecular level. Moving forward, tissue-based expression profiling would be the next obvious step in understanding gene functions of Anopheles stephensi. We report here the first study, to the best of our knowledge, on transcriptomic profile of four important organs of an adult female Anopheles stephensi mosquito (midgut, Malpighian tubules, fat body and ovary). In all, we identified over 21,000 transcripts corresponding to more than 12,000 gene loci from these four tissues. This study provides the tissue-based expression profiles of majority of annotated transcripts in Anopheles stephensi genome, and the dynamics of alternative splicing in these tissues. Understanding the transcript expression and gene function at the tissue level would immensely help in enhancing our knowledge of this important vector and decipher the putative role of these tissues. This knowledge might in turn provide the basis of selection of candidates for future studies on vectorial ability and novel molecular targets to intercept malaria transmission.
Project description:In Sub-Saharan Africa, Anopheles gambiae Giles (Diptera: Culicidae) largely contributes to malaria transmission, in direct relation to environmental conditions influencing the vector ecology. Therefore, our study aimed to compare the proteomes of An. gambiae according to varying insecticide pressures associated to cotton crops also integrating different population origins from two climatic regions of Burkina Faso.
Project description:Ascertain the transcriptional response of the major malaria vector Anopheles coluzzii to the pyrethroid deltamethrin over ten time points.
Project description:Resistance to pyrethroids, the only insecticide approved for bednets, threatens control of the major malaria vector, Anopheles funestus, in Malawi. To improve the management of such resistance countrywide, it is crucial to understand the dynamics and mechanisms driving resistance in the field. In this study the levels of insecticide resistance were determined across the highly endemic densely populated lake and southern agricultural area. Insecticide resistance to pyrethoids was assessed using standardized WHO bioassay methods and resistant mosquitoes were hybridized to susceptible mosquitoes. This microarray analysis revealed the key role of cytochrome P450 genes such as CYP6P9a, CYP6P9b and CYP6M7. However, a significant shift in the over-expression of these CYP450s was detected across a south/north transect, with CYP6M7 more highly over-transcribed in the two northern collection sites and the tandemly duplicated genes, CYP6P9a and CYP6P9b, more greatly over-transcribed in the south.
Project description:Contrasting genomic signatures of selection driven by insecticide resistance between populations of the major malaria vector Anopheles funestus in Africa
Project description:Anopheles gambiae mosquitoes play an important role in malaria transmission. In sub-Saharan Africa, the dry season can last several months. The mechanisms for mosquito population to survive through the dry season are poorly understood. One possible mechanism is that adults increase their desiccation tolerance over the dry season. Genetic analyses have shown that inversions 2La, 2Rb, 2Rc, 2Rd and 2Ru are associated with aridity resistance, however little is known about the transcriptional response of genes in response to desiccation. The results of the present study demonstrate that desiccation affects expression of genes associated with several mosquito physiological mechanisms, including those that protect against water loss, but all structural related genes decreased their expression. The identified differentially expressed genes in response to desiccation stress can lay a foundation for better understanding of molecular mechanisms underling dry-season survival of An. gambiae mosquitoes, so it may provide a different option for malaria vector control.
