ABSTRACT: 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: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.
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:During intra-erythrocytic development, late asexually replicating Plasmodium falciparum parasites sequester from peripheral circulation. This facilitates chronic infection and is linked to severe disease and organ-specific pathology including cerebral and placental malaria. Immature gametocytes M-bM-^@M-^S sexual stage precursor cells M-bM-^@M-^S likewise disappear from circulation. Recent work has demonstrated that these sexual stage parasites are located in the hematopoietic system of the bone marrow before mature gametocytes are released into the blood stream to facilitate mosquito transmission. However, as sequestration occurs only in vivo and not during in vitro culture, the mechanisms by which it is regulated and enacted (particularly by the gametocyte stage) remain poorly understood. We generated the most comprehensive P. falciparum functional gene network to date by integrating global transcriptional data from a large set of asexual and sexual in vitro samples, patient-derived in vivo samples, and a new set of in vitro samples profiling sexual commitment. We defined more than 250 functional modules (clusters) of genes that are co-expressed primarily during the intra-erythrocytic parasite cycle, including 35 during sexual commitment and gametocyte development. Comparing the in vivo and in vitro datasets allowed us, for the first time, to map the time point of asexual parasite sequestration in patients to 22 hours post invasion, confirming previous in vitro observations on the dynamics of host cell modification and cytoadherence. Moreover, we were able to define the properties of gametocyte sequestration, demonstrating the presence of two circulating gametocyte populations: gametocyte rings between 0 and ~30 hours post invasion and mature gametocytes after around 7 days post invasion. We used 164/TdTom, a transgenic parasite line expressing a red fluorescent protein reporter under a gametocyte-specific promoter to generate schizont samples. Schizonts were subsequently isolated from both the fluorescent and non-fluorescent population by FACS and prepared for microarray analysis. Two biological replicates were produced for both the fluorescent and the non-fluorescent samples.
Project description:Gametocytogenesis and gametogenesis in malaria parasites are complex processes of cell differentiation and development likely involving many gene products. Gametocytes develop in the blood of the vertebrate host but mature gametocytes are not activated until taken up by the mosquito vector. Several distinct mutants have been described that block gametogenesis but the detailed molecular causes for the mutant phenotypes are not understood. To investigate whether a block in gametogenesis also results in a changed transcriptional profile, we studied two gene deletions mutants; act2(-) lacking stage-specific actin II and CDPK4(-) lacking calcium-dependent protein kinase 4. Whole-genome microarray analysis was performed from RNA of mature gametocytes to compare the transcriptomes of the mutants with wild-type Plasmodium berghei. The microarray analysis identified ~12% of all genes being differentially expressed in either or both mutants compared to normal gametocytes, as defined by at least two-fold change in transcript abundance. A large proportion of differentially expressed genes in both mutants overlapped consistent with the developmental gametocyte arrest. Distinct profiles in each mutant were also observed. Microarray experiments were performed as dual-color hybridizations on Agilent-024169 custom whole genome Plasmodium berghei 44K arrays. To compensate for dye-specific effects, a dye-reversal color-swap was applied.
Project description:Plasmodium berghei transcriptomes of wild-type ANKA (WT) and garid knockout parasites [garid(-)] were analyzed at the gametocyte stage.
Project description:Plasmodium berghei transcriptomes of pbap2-fg2 and ap2r-2 knockout parasites [pbap2-fg2(-) and ap2r-2(-), respectively] were analyzed at the gametocyte stage.
Project description:Twenty years since publication of the Plasmodium falciparum and P. berghei genomes one-third of their protein-coding genes lack functional annotation. In the absence of sequence and structural homology, protein-protein interactions can facilitate functional prediction of such orphan genes by mapping protein complexes in their natural cellular environment. The Plasmodium NPC (nuclear pore complex) is a case in point: it remains poorly defined; its constituents lack conservation with the 30+ proteins described in the NPC of many opisthokonts, a clade of eukaryotes that includes fungi and animals, but not Plasmodium. Here we developed a labeling methodology based on TurboID fusion proteins, which allows visualization of the berghei NPC and facilitates the identification of its components. Following affinity purification and mass spectrometry we identify four known Nups (138, 205, 221, and the bait 313) and verify interaction with the putative FG Nup637; we assign five proteins lacking annotation (and therefore meaningful homology with proteins outside the genus) to the NPC, which is confirmed by GFP tagging. Based on gene deletion attempts, all new Nups Nup176, 269, 335, 390, and 434 are essential to parasite survival. They lack primary sequence homology with proteins outside the Plasmodium genus; albeit two incorporate short domains with structural homology to human Nup155 and yeast Nup157, and the condensin SMC4. The protocols developed here showcase the power of proximity-labeling for elucidating protein complex composition and annotation in Plasmodium. It opens the door to exploring the function of the Plasmodium NPC and understanding its evolutionary position.
Project description:AP2-FG is a female-specific transcription factor (TF) that plays an essential role in female gametocyte development. AP2-FG activates hundreds of genes by binding to a female-specific ten-base cis-acting element. Here, we report that in the rodent malaria parasite Plasmodium berghei, another female-specific TF designated as a partner of AP2-FG (PFG), controls gene expression in female gametocytes cooperatively with AP2-FG. Transcriptional mechanisms were analyzed in Plasmodium berghei female gametocytes.
Project description:AP2-FG is a female-specific transcription factor (TF) that plays an essential role in female gametocyte development. AP2-FG activates hundreds of genes by binding to a female-specific ten-base cis-acting element. Here, we report that in the rodent malaria parasite Plasmodium berghei, another female-specific TF designated as a partner of AP2-FG (PFG), controls gene expression in female gametocytes cooperatively with AP2-FG. Transcriptional mechanisms were analyzed in Plasmodium berghei female gametocytes.
Project description:Quantitative studies of the P. falciparum transcriptome have shown that the tightly controlled progression of the parasite through the intraerythrocytic developmental cycle (IDC) is accompanied by a continuous gene expression cascade where most expressed genes exhibit a single transcriptional peak. Since proteins represent the decisive business end of gene expression, understanding the correlation between mRNA and protein levels is crucial for inferring biological activity from transcriptional gene expression data. While pertinent studies on other organisms show that as little as 20-40% of protein abundance variation may be attributable to corresponding mRNA levels, the situation in Plasmodium is further complicated by the dynamic nature of the cyclic gene expression cascade where the mRNA levels of most genes change constantly during the IDC. In this study, we simultaneously determined mRNA and protein abundance profiles for P. falciparum parasites during the IDC at 2-hour resolution based on spotted oligonucleotide microarrays and 2D-protein gels in combination with DIGE fluorescent dyes. Intriguingly, most proteins are represented by more than one isoform, presumably due to post-translational modifications. Analysis of 366 protein abundance profiles and the corresponding mRNA levels shows that in 67.2% of cases the protein abundance peaks at least 8 hours after the mRNA level peak. While it may be tempting to interpret this as evidence for widespread post-transcriptional gene regulation additional analyses including computer modeling demonstrate that in >60% of these cases the observed protein profiles including the peak lag times could arise as a consequence of the corresponding mRNA levels when simple translation and degradation dynamics are assumed. We further characterize and illustrate these dynamics and show that even human host proteins within the parasite may be subject to similar dynamics as their parasite counterparts. 24 timepoint samples were harvested from a tightly synchronous 6.5 liter biofermenter culture of P. falciparum (Dd2) at 2-hour intervals during one entire intraerythrocytic developmental cycle and compared against a 3D7 RNA reference pool.