Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with pyrimethamine
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with WR99210
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with pyrimethamine
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with pyrimethamine RNA from pyrimethamine-treated parasite vs RNA from untreated control, Pyr-sensitive TM4/8.2 strain, pyrimethamine concentration at IC50 and treated for 0 h and 24 h, microarray data were obtained from at least four hybridizations using RNA from at lease two independent parasite cultures
Project description:Comaprision of P.falciparum clinical isolates showing Uncomplicated disease with that shwoing complicated disease(Cerebral malaria) The experiment was designed to try and identify differences if any, at the genome level between P.falciparum isolates from patients with uncomplicated malaria vs. patients with complicated malaria (Cerebral malaria). The emphasis was to highlight possible amplifications/deletions in different regions of the parasite genome.
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with pyrimethamine RNA from pyrimethamine-treated parasite vs RNA from untreated control, Pyr-sensitive TM4/8.2 parasite strain, pyrimethamine concentration at IC50 and treated for 2 h, 4 h, and 8 h, microarray data were obtained from at least four hybridizations using RNA from at least two independent parasite cultures
Project description:To help malaria parasites survive unpredictable host immune responses, it is known that genes for surface proteins express stochastically in Plasmodium falciparum. Here, we demonstrate that gene expression for intracellular metabolic functions may be preordained and insensitive to specific metabolic perturbations. In a tightly-controlled, large microarray study involving over 100 hybridizations to isogenic drug-sensitive and drug-resistant parasites, the lethal antifolate WR99210 failed to over-produce RNA for the biochemically and genetically proven target dihydrofolate reductase-thymidylate synthase (DHFR-TS). Beyond the target, this transcriptional obstinacy carried over to the rest of the parasite genome, including genes for target pathways of folate and pyrimidine metabolism. Even 12 hours after commitment to death, the transcriptome remained faithful to evolutionarily entrained paths. A system-wide transcriptional disregard for metabolic perturbations in malaria parasites may contribute to selective vulnerabilities of the parasite to lethal antimetabolites. While large protective metabolic responses were not detected, DNA microarrays helped capture small, but reproducible drug-dependent perturbations within hours of drug exposure. In addition, in Plasmodium cells that had adapted to long-term drug exposure, DNA microarrays revealed new, large genome-wide transcriptional adjustments in the hard-wired transcriptional program itself. Keywords: Plasmodium falciparum treated with WR99210 RNA from P. falciparum Dd2 and B1G9 (WR99210 resistant cell-line) trophozoites that had been treated with 10 nM WR99210 for varying durations (3, 6, 9, 15, 18, 21 and 24h) was hybridized against a common pool of trophozoite RNA from a cognate clone, a culture containing 0.1% (v/v) DMSO lacking drug was used as untreated control, microarray data were obtained from at least four hybridizations using RNA from two independent parasite cultures
Project description:Malaria pathogenesis results from the asexual replication of Plasmodium falciparum within human red blood cells, which relies on a precisely timed cascade of gene expression over a 48-hour life cycle. However, post-transcriptional control of this hardwired program has been largely unexplored. To this end, we performed a comprehensive characterization of m6A mRNA methylation during the different developmental stages. Using mass spectrometry and parallel m6A and RNA sequencing, we show that m6A is developmentally regulated and present at higher levels (>4-fold) than in other organisms investigated. Knockdown of the m6A methyltransferase by CRISPR interference leads to increased levels of transcripts that normally contain m6A. In accordance, we find an inverse correlation between m6A status and mRNA half-life or translational efficiency. Our data demonstrate the crucial function of extensive m6A mRNA methylation in dynamically fine-tuning the transcriptional program of a unicellular eukaryote and reveal a new ‘epitranscriptomic’ layer of gene regulation in malaria parasites.