RNA-seq of Plasmodium berghei PbWT and PbHMGB1KO parasite strains
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ABSTRACT: The purpose of the experiment is to identify the differential gene expression pattern of PbHMGB1KO parasites with respect to the PbWT parasites.
Project description:Commitment to and completion of sexual development are essential for malaria parasites to be transmitted through mosquitoes. The molecular mechanism(s) responsible for these processes however, remain largely unknown. We have identified two transcription factors (both belonging to the AP2 family) essential for gametocytogenesis. AP2-G mutants are characterised by a complete inability to produce gametocytes. In AP2-G2 mutants the gametocytaemia is very significantly reduced but not completely abolished. We have performed the microarray experiments in order to cokmpare the transcriptomes of these mutantnts to the WT parasites and between each other. As P.berghei parasites are characterised by asynchronous development in the rodent host, the different stage composition of the sample would impact the analysis. Therefore parasites were harvested and matured in in vitro to the schizont stage Pairwaise comparison between the mutants and parental line was performed. 3 biological replicates of each condition were used.
Project description:The microarray experiments were carried out using a long oligonucleotide DNA microarray that represent all 5363 P. falciparum genes with one oligonucleotide per 1.9kb of coding sequence on average (Hu et al. 2007). Total 247 microarray experiments were carried out including 29-drug treatment time courses with 20 compounds and corresponding untreated controls from different drug or inhibitor treatment. Data of each drug/inhibitor experiment were normalized using a linear normalization and background filtering as implemented by the NOMAD database (http://derisilab.ucsf.edu). Time-series sampling and experiments with synchronized ex vivo culturing parasites. Each experiment has treatment and controls, and starts at a specific time of post invasion. For an example of quinine treatment, the treatments start from late ring stage through trophozoite stage of the parasites. First, IC50 is determined by drug assay with synchronized parasites (5% parasiteomia and 2% RBC). Second, synchronized parasite cultures are splitted into 12 flasks (75ml culture/flask) for a 6 time-point time-series experiment. 6 flasks are treated with quinine (final concentration is IC50) and 6 flasks are negative controls. 1,2,4,6,8 and 10 hrs after the treatment, parasites in each flask were harvested for total RNA isolation and microarray hybridizaiton.
Project description:The aim was to understand the molecular basis of the parasite response to DR. Transcriptomic analysis of synchronized wildtype parasites, collected with 4h intervals, from mice under the two dietary conditions. We found that WT parasites on DR and control diets have different transcriptomes, with a remarkable general repression of transcription in DR.
Project description:To identify protein phosphatases (PP) that are essential during asexual blood stage development in Plasmodium berghei, we attempted systematic deletion of the 30 P. berghei PP genes using double homologous recombination. Of these, we performed strand-specific RNA-sequencing (RNA-Seq) analysis for 2 myristoylated PP mutants _ppm2 and _ppm5 lines across relevant lifestages ( activated gametocyte and schizont stages in both _ppm2 and _ppm5 and ookinete stage in _ppm5 alone). Two to four biological replicates each for _ppm2, _ppm5 and wild-type parasites were processed into strand-specific RNA-seq libraries and sequenced in Illumina Hiseq platform using 100-bp paired end chemistry.
Project description:Transcriptional profiling of gametocyte non-producer lines in Plasmodium berghei Transcriptome of gametocyte non producer lines (natural and genetic KO) and parental (820) lines. The aim of the study was to identify key genes involved in the decision to commit to gametocytogenesis in Plasmodium berghei. These microarrays compare naturally selected lines that do not produce gametocytes, and the parental line and additionally a genetic knock out of AP2-G PBANKA_143750. Data published Sinha, Hughes, et, al Nature tbc. 2- colour microarray comparing to common background pool (containing all life cycle stages). Replicates of different life cycle stages of gametocyte non-producer lines and wild tye (WT) parental control lines
Project description:Many eukaryotic developmental and cell fate decisions are effected post-transcriptionally that mechanistically involve RNA binding proteins as regulators of translation of key mRNAs. In the unicellular eukaryote malaria parasite, Plasmodium, one of the most dramatic changes in cell morphology and function occurs during transmission between mosquito and human host. In the mosquito salivary glands, Plasmodium sporozoites are slender, motile and remain infectious for several weeks; only after transmission and liver cell invasion, does the parasite rapidly transform into a round, non-motile exo-erythrocytic form (EEF) that gives rise to thousands of infectious merozoites to be released into the blood stream. Here we demonstrate a Plasmodium homolog of the RNA binding protein, Pumilio, as a key regulator of the sporozoite to EEF transformation. In the absence of Pumilio-2 (Puf2) Plasmodium berghei sporozoites initiate early stage EEF development inside mosquito salivary glands with characteristic morphological changes; puf2- salivary gland sporozoites lose gliding motility, cell traversal ability and are less infective. Global expression profiling confirmed that transgenic parasites exhibit genome-wide transcriptional adaptations typical for Plasmodium intra-hepatic development. The data demonstrate that Puf2 is a key player in regulating developmental control, and imply that transformation of salivary gland-resident sporozoites into early liver stage parasites is regulated by a post-translational mechanism.