Project description:To examine the effects of 20E treatment on mosquito gene expression, treated mosquito cells were examined by RNA-seq to determine the influence of 20E treatment.
Project description:A deeper understanding of malaria parasite development inside the Anopheles mosquito may lead to the identification of processes that can be targeted by transmission-blocking interventions. Paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) is a potent superoxide-inducing agent that impacts Plasmodium ookinete development, especially at higher concentrations. Compounds like Paraquat can potentially induce an oxidative imbalance in the mosquito midgut during ookinete maturation, essentially super-stressing the parasite leading to the arrested development of ookinetes, the only stage that can invade through a mosquito midgut cell to establish an oocyst infection in the mosquito. The mosquito midgut has evolved to handle the natural production of reactive oxygen and nitrogen species (ROS and RNS, respectively) as a result of feeding on blood. The addition of Paraquat to a bloodmeal is expected to induce a cognate response in the midgut to handle the excess ROS/RNS, and high concentrations of this compound can potentially overwhelm the midgut response leading to mosquito death. While several studies have explored the effect of Paraquat on malaria parasites, a fundamental understanding of the mosquito response to this compound remains unknown. Here, we quantified the mosquito midgut proteomic response to a Paraquat-laced sugar meal to understand the intrinsic midgut response (in the absence of a bloodmeal). We then carried out transcriptomic analysis of the mosquito midgut for several antioxidants of the Trx and GSH pathways to compare concordance or discordance between protein and its transcripts during different oxidative stress conditions. Finally, we determined whether the same Trx and GSH pathways are upregulated following infection with either P. falciparum or P. berghei at 24 hrs post-blood feeding, coinciding with the time point for maximal ookinete traversal of the midgut. We discuss the potential selective action of Paraquat on the parasite and the intrinsic tolerance of the mosquito midgut to Paraquat-mediated oxidative stress.
Project description:Insects, unlike vertebrates, are generally believed to lack steroid hormones with functions predominantly associated with adult male biology. In the malaria mosquito Anopheles gambiae, the ecdysteroid 20-hydroxyecdysone (20E) appears to both control egg development in females and induce mating refractoriness and oviposition when sexually transferred by males. Here we show that these sex-specific functions are instead carried out by distinct steroids. We identify a male-specific oxidized form of 20E (3D20E) that upon sexual transfer switches off female mating receptivity, ensuring male paternity. Endogenous female 20E does not induce mating refractoriness, while it triggers oviposition in mated females when expression of a 20E-inhibiting kinase is repressed. 3D20E and 20E have different downstream targets, with 3D20E inducing expression of a tolerance factor that preserves female fitness during Plasmodium infection. The evolution of this male steroid has therefore not only shaped the mating biology of An. gambiae, but also impacted malaria transmission.
Project description:Mosquito midgut is the first tissue encounter the virus. We apply single cell RNA sequencing to investigate the gene difference in cell level between blood fed and Zika virus infected midgut.
Project description:The Anopheles gambiae midgut harbors bacteria that proliferate upon a blood feed. We used microarrays to examine the midgut gene expression response at early stages (3hours) after an artifitial meal containing heat killed bacteria. Anopheles gambiae G3 mosquitoes 5-6 day-old were fed BSA (20% in PBS with fresh 10 mM sodium bicarbonate) with or without heat killed E. coli (equivalent of 2.5 ml of 0.8 OD) . Three pools of 10 mosquito midguts were dissected after 3h and processed for microarray analysis of gene expression.
Project description:Malaria inflicts the highest rate of morbidity and mortality among the vector-borne diseases. The dramatic bottleneck of parasite numbers that occurs in the gut of the obligatory mosquito vector provides a promising target for novel control strategies. Using single-cell transcriptomics, we analyzed Plasmodium falciparum development in the mosquito gut, from unfertilized female gametes through the first 20 hours post blood feeding, including the zygote and ookinete stages. This study revealed the temporal gene expression of the ApiAP2 family of transcription factors, and of parasite stress genes in response to the harsh environment of the mosquito midgut. Further, employing structural protein prediction analyses we found several upregulated genes predicted to encode intrinsically disordered proteins (IDPs), a category of proteins known for their importance in regulation of transcription, translation and protein-protein interactions. IDPs are known for their antigenic properties and may serve as suitable targets for antibody or peptide-based transmission suppression strategies. In total, this study uncovers the P. falciparum transcriptome from early-to-late parasite development in the mosquito midgut, inside its natural vector, which provides an important resource for future malaria transmission-blocking initiatives. Single-cell data can be visualized interactively via https://mubasher-mohammed.shinyapps.io/shinyapp/ In-house bash, R code scripts and data that were implemented in this study are available on GitHub https://github.com/ANKARKLEVLAB/Single-cell-P.falciparum-midgut .
Project description:We conducted a genome wide survey of mosquito gene expression profiles in 4 different tissues of adult Anopheles gambiae mosquitoes. The tissues included the head, the midgut, the carcass (corresponding to the remainder of the mosquito after decapitation and midgut removal) and ovaries. Ovaries were collected from adult female mosquitoes, which had been bloodfed 48h prior to dissection. To investigate mosquito expression in those tissues, we performed competitive two-dye hybridizations of experimental and standard reference RNA samples to MMC1 microarrays. MMC1 microarrays contain approximately 20,000 EST clones. Standard reference RNA was produced in vitro from the spotted ESTs and was utilized to provide consistent, non-zero reference values for almost all probes of the array. For the experiment, two biological replicates, corresponding to mosquito generations 1 and 3 (generation 2 was discarded due to probable labelling errors) and one technical (dye-swap) replicate was conducted.
Project description:Mosquitoes are the most notorious hematophagous insects and due to their blood feeding behavior and genetic compatibility, numerous mosquito species are highly efficient vectors for certain human pathogenic parasites and viruses. The mosquito midgut is the principal organ of blood meal digestion and nutrient absorption. It is also the initial site of infection with blood meal acquired parasites and viruses. We conducted an analysis based on single-nucleus RNA sequencing(snRNA-Seq) to assess the cellular diversity of the midgut and how individual cells respond to blood meal ingestion to facilitate its digestion.