Project description:Mayaro virus (MAYV) is a mosquito-borne Alphavirus responsible for outbreaks in South America and the Caribbean. In this study we infected Anopheles stephensi with MAYV and sequenced mRNA and small RNA to understand how MAYV infection impacts gene transcription and the expression of small RNAs in the mosquito vector. Genes involved with innate immunity and autophagy are regulated in response to MAYV infection of An. stephensi, we also discover novel miRNAs and describe their expression patterns following bloodmeal ingestion. These results suggest that MAYV does induce a molecular response to infection in its mosquito vector species and that MAYV may have mechanisms to evade the vector immune response.
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:Background: Anopheles culicifacies is a rural vector of malaria in tropical and sub tropical South East Asian region. The salivary gland of the mosquito is the target for sporozoite interaction, blood feeding behavior, haemostasis and vector-parasite interactions. Malaria parasite matures inside the salivary gland, gain competence and transmitted to the host along with the saliva during biting. The importance of the proteins expressed in salivary gland is the first step in understanding the physiology of blood feeding and may provide insights into vector- parasite interactions. Since, no genomic or transcriptomics information is available of Anopheles culicifacies, therefore locally expressed functional proteins in salivary glands are of much importance. . Method: In this study, 1DE protein and in solution digestion was combined with tandem mass spectrometry (nano LC-MS/MS) and computational bioinformatics for data mining was employed to study the proteome profile of salivary glands of sugar fed An. culicifacies mosquito species. Functional annotation of all the identified proteins was carried out using gene ontology tools, CELLO and SMART analysis software. Results: Total 102 proteins were identified and analysed by SEQUEST algorithm against mosquito protein database from Uniprot/NCBI. Out of which 81 proteins were identified using gel free approach and 21 proteins using in-gel approach and 15 were common among these two approaches. All the identified proteins were categorized in to 23 groups of biological processes using GO tool. 7 proteins were depicted to be secretary in nature by investigating the signal peptide present. Potential proteins with unknown function were predicted by analyzing their functional association with other characterized proteins by STRING algorithm and were categorized in cell adhesion, cytoskeleton and membrane trafficking networks. Conclusion: Our study elucidates the first proteomic dataset of An. culicifacies salivary gland proteins. Functional annotation of salivary proteins and complementary gene ontology assignments in An. culicifacies species may contribute towards understanding the complex physiology of the tissues in this species. This proteome baseline data may facilitate the discernment of salivary glands and parasite correlation during blood feeding. Furthermore, this mass spectrometry based proteomic data may also provide insights into the elucidation of role of differential functional proteins present in refractory An. culicifacies mosquito and may be useful for development of effective malaria control strategies.
Project description:Anopheles gambiae mosquitoes are primary human malaria vectors, but we know very little about their mechanisms of transcriptional regulation. We profiled chromatin accessibility by ATAC-seq in laboratory-reared An. gambiae mosquitoes experimentally infected with the human malaria parasite Plasmodium falciparum. By integrating ATAC-seq, RNA-seq and ChIP-seq data we showed a positive correlation between accessibility at promoters and introns, gene expression and active histone marks. By comparing expression and chromatin structure patterns in different tissues, we were able to infer cis-regulatory elements controlling tissue specific gene expression and to predict the in vivo binding sites of relevant transcription factors. The ATAC-seq assay also allowed the precise mapping of active regulatory regions, including novel transcription start sites and enhancers that annotate to mosquito immune-response genes. This study is important not only for advancing our understanding of mechanisms of transcriptional regulation in the mosquito vector of human malaria, but also the information we produced is of great potential for developing new mosquito-control and anti-malaria strategies.
Project description:Background: The mosquito Anopheles gambiae is a major vector of human malaria. Increasing evidence indicates that blood cells (hemocytes) comprise an essential arm of the mosquito innate immune response against both bacteria and malaria parasites. To further characterize the role of hemocytes in mosquito immunity, we undertook the first genome-wide transcriptomic analyses of adult female An. gambiae hemocytes following infection by two species of bacteria and a malaria parasite. Results: We identified 4047 genes expressed in hemocytes, using An. gambiae genome-wide microarrays. While 279 transcripts were significantly enriched in hemocytes relative to whole adult female mosquitoes, 959 transcripts exhibited immune challenge-related regulation. The global transcriptomic responses of hemocytes to challenge with different species of bacteria and/or different stages of malaria parasite infection revealed discrete, minimally overlapping, pathogen-specific signatures of infection-responsive gene expression; 105 of these represented putative immunity-related genes including anti-Plasmodium factors. Of particular interest was the specific co-regulation of various members of the Imd and JNK immune signaling pathways during malaria parasite invasion of the mosquito midgut epithelium. Conclusion: Our genome-wide transcriptomic analysis of adult mosquito hemocytes reveals pathogen-specific signatures of gene regulation and identifies several novel candidate genes for future functional studies.
Project description:Anopheles gambiae mosquitoes transmit the human malaria parasite Plasmodium falciparum, which causes the majority of fatal malaria cases worldwide. The hematophagous life style defines the mosquito reproductive biology and is exploited by P. falciparum for its own sexual reproduction and transmission. The two main phases of the mosquito reproductive cycle, pre-vitellogenic (PV) and post-blood meal (PBM) shape its capacity to transmit malaria. Transition between these phases is tightly coordinated to ensure homeostasis between mosquito tissues and successful reproduction. One layer of control is provided by microRNAs, well-known regulators of blood meal digestion and egg development in mosquitoes. Here, we report a global overview of tissue-specific miRNA expression during the PV and PBM phases and identify miRNAs regulated during PV to PBM transition. The observed coordinated changes in the expression levels of a set of miRNAs in the energy-storing tissues suggest a role in the regulation of blood meal-induced metabolic changes.
Project description:Senescence is a biological phenomenon experienced by all living eukaryote organisms. Genome-wide gene expression associated with aging has been explored in model organisms such as Drosophila melanogaster and Caenorhabditis elegans, but this has not been well understood in African malaria vector, Anopheles gambiae. Gene expression profiling using DNA microarray allows for simultaneous study of changes in mRNA levels for thousands of genes. This study examined genome-wide gene expression during aging process in An. gambiae. The influence of blood feeding on gene expression was also examined. The data can be used to further our understanding of mosquito senescence and identify biomarkers for mosquito age grading.